2012 North Carolina Fuel Gas Code Level II Level II Training

1 2012 North Carolina Fuel Gas Code Level II Level II Tra...

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2 2012 North Carolina Fuel Gas Code Level II12/1/2017 Overview Chapter 1: Administration Chapter 2: Definitions Chapter 3: General Regulations Chapter 4: Gas Piping Installations Chapter 5: Chimneys and Vents Chapter 6: Specific Appliances Chapter 7: Gaseous Hydrogen Systems Chapter 8: Referenced Standards 2 Copyright 2012, International Code Council

3 2012 North Carolina Fuel Gas Code Level II12/1/2017 Description This seminar highlights essential provisions of the 2012 North Carolina State Fuel Gas Code® and provides practice in applying key requirements. It reinforces learning by supplying immediate feedback or clarification. It walks participants through the content outline of the code book, highlights and describes important sections. 3 Copyright 2012, International Code Council

4 2012 North Carolina Fuel Gas Code Level II12/1/2017 Goal Participants will be able to apply key code sections of the 2012 North Carolina State Fuel Gas Code to aid in its administration and enforcement while performing their jobs. 4 Copyright 2012, International Code Council

5 2012 North Carolina Fuel Gas Code Level II12/1/2017 Objectives Upon completion, participants will be better able to: Summarize the purpose and content of each chapter contained in the 2012 North Carolina State Fuel Gas Code®. Describe the intent and application of major sections within the 2012 North Carolina State Fuel Gas Code®. Explain the application of the 2012 North Carolina State Fuel Gas Code® through inspection, plan review and enforcement. 5 Copyright 2012, International Code Council

6 2012 North Carolina Fuel Gas Code Level II12/1/2017 Target Audience Architects Building Inspectors Building Officials Contractors Engineers Plans Examiners 6 Copyright 2012, International Code Council

7 Introduction to the 2012 North Carolina Fuel Gas Code2012 North Carolina Fuel Gas Code Level II 12/1/2017 Introduction to the 2012 North Carolina Fuel Gas Code Purpose – Designed to meet needs through model code regulations that safeguard health, safety, property and public welfare internationally. Adoption – In accordance with proceedings establishing the jurisdiction’s laws. Maintenance – Kept up-to-date through the review of proposed changes considered through an open code development process. 7 Copyright 2012, International Code Council

10 Chapter 1: Administration2012 North Carolina Fuel Gas Code Level II 12/1/2017 Chapter 1: Administration This chapter is concerned with maintaining “due process of law” in enforcing the performance criteria contained in the code. Only through careful observation of the administrative provisions can the code official reasonably hope to demonstrate that “equal protection under the law” has been established. Chapter 1 is largely concerned with maintaining “due process of law” in enforcing the performance criteria contained in the code. Only through careful observation of the administrative provisions can the code official reasonably hope to demonstrate that “equal protection under the law” has been established. Although it is generally assumed that the administrative and enforcement sections of a code are geared toward the code official, this is not entirely true. The provisions also establish the rights and privileges of the registered design professional, the contractor and the building owner. The position of the code official is merely to review the proposed and completed work and determine whether a fuel gas installation conforms to the code requirements. The registered design professional is responsible for the design of a safe, sanitary fuel gas system. The contractor is responsible for installing the system in strict accordance with the plans. 10 Copyright 2012, International Code Council

11 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section 101 General The scope of the code covers the initial design, installation, construction, and maintenance of: Gas piping systems Fuel gas appliances Gaseous hydrogen systems 11 Copyright 2012, International Code Council

12 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section 101 General The responsibilities of the various professionals include: The code official – reviews the proposed work for code compliance, checks for maintenance of the spirit and intent of the law, and verifies that the fuel gas system provides adequate protection of the public. The design professional – designs a safe, operational fuel gas system. The contractor – installs the system in strict accordance with the plans and/or manufacturer’s installation requirements. 12 Copyright 2012, International Code Council

13 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section Intent The purpose of the code is to provide minimum standards to safeguard life or limb, health, property and public welfare by regulating and controlling the design, construction, installation, quality of materials, location, operation and maintenance or use of fuel gas systems. The intent of the code is to set forth requirements that establish the minimum acceptable level to safeguard life or limb, health, property and public welfare. The intent becomes important in the application of such sections as Sections 102, 104.2, and 108, as well as any enforcement-oriented interpretive action or judgment. Like any code, the written text is subject to interpretation. Interpretations should not be affected by economics or the potential impact on any party. The only consideration should be protection of the public health, safety and welfare. 13 Copyright 2012, International Code Council

14 Section 102 Applicability2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 102 Applicability Existing installations Maintenance Additions, alternations or repairs Change in occupancy Historic buildings Moved buildings Referenced codes and standards Requirements not covered by this code The scope of the code as described in Section 101 is referenced in this section. The most restrictive code requirement is to apply where different requirements may be specified in the code for a specific installation. The code is designed to regulate new construction and new work and is not intended to be applied retroactively to existing buildings except where existing fuel-gas-related systems are specifically addressed in this section and Section 108. 14 Copyright 2012, International Code Council

15 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section 105 Approval The code official may amend or make exceptions to the code as needed where strict compliance with the code is impractical. Only the code official has the authority to grant modifications. Modifications and consideration of alternatives to code provisions are addressed in this section. The code official may amend or make exceptions to the code as needed where strict compliance with the code is impractical. Only the code official has the authority to grant modifications. Consideration of a particular difficulty is to be based on the application of the owner and a demonstration that the intent of the code is satisfied. This section is not intended to permit setting a code provision aside or ignoring a provision; rather, it is intended to provide for the acceptance of equivalent protection. Such modifications do not, however, extend to actions that are necessary to correct violations of the code. In other words, a code violation or the expense of correcting a code violation cannot constitute a practical difficulty. Details of the modification must be filed for later retrieval to substantiate the reasons for the modification. Comprehensive written records are an essential part of an effective administrative system. Unless clearly written records of the considerations and documentation used in the modification process are created and maintained, subsequent enforcement action cannot be supported. 15 Copyright 2012, International Code Council

16 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section 106 Permits A permit is required for all activities that are regulated by the code, and these activities cannot begin until the permit is issued. Replacement of an existing piece of equipment or related piping is treated no differently from a new installation in new building construction. A permit causes the work to be inspected to determine compliance with the intent of the code. In general, a permit is required for all activities that are regulated by the code, and these activities cannot begin until the permit is issued. A fuel gas permit is required for the installation, replacement, alteration or modification of fuel gas systems and components that are in the scope of applicability of the code. Replacement of an existing piece of equipment or related piping is treated no differently than a new installation in new building construction. A permit causes the work to be inspected to determine compliance with the intent of the code. 16 Copyright 2012, International Code Council

17 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section 106 Permits Exception: When appliance and equipment replacements and repairs are needed in an emergency situation, the permit application will be submitted within the next working business day of the Department of Inspection. The exception provides for prompt permit applications for situations where equipment and appliance replacements and repairs are done to address an emergency. This action enables the department having jurisdiction to promptly inspect the work. 17 Copyright 2012, International Code Council

19 2012 North Carolina Fuel Gas Code Level II12/1/2017 Chapter 2: Definitions Chapter 2 provides an alphabetical listing of terms that are commonly used throughout the code. Codes, by their very nature, are technical documents. Literally every word, term and punctuation mark can add to or change the meaning of the intended result. This is even more so with performance code text where the desired result often takes on more importance than the specific words. 19 Copyright 2012, International Code Council

20 2012 North Carolina Fuel Gas Code Level II12/1/2017 Definitions Appliance – Any apparatus or device that utilizes gas as a fuel or raw material to produce light, heat, power, refrigeration or air conditioning. An appliance is a manufactured component or assembly of components that converts one source of energy into a different form of energy to serve a specific purpose. The term “appliance” generally refers to residential- and commercial-type utilization equipment that is manufactured in standardized sizes or types. The term “appliance” is generally not associated with industrial-type equipment. For the application of the code provisions, the terms “appliance” and “equipment” are not interchangeable. 20 Copyright 2012, International Code Council

21 2012 North Carolina Fuel Gas Code Level II12/1/2017 Definitions Appliance shutoff valve. A valve located in the piping system, used to isolate individual appliances for purposes such as service or replacement. The definition makes it clear that the primary purpose of an appliance shutoff valve is not related to the emergency shutoff of the appliance. 21 Copyright 2012, International Code Council

22 2012 North Carolina Fuel Gas Code Level II12/1/2017 Definitions Barometric Draft Regulator – A balanced damper device attached to a chimney, vent connector, breeching or flue gas manifold to protect combustion appliances by controlling chimney draft. A double-acting barometric draft regulator is one whose balancing damper is free to move in either direction to protect combustion appliances from both excessive draft and backdraft. These units automatically open or close depending on the difference between the internal vent pressure and the atmospheric pressure. See the commentary for the definition of “Atmospheric pressure.” Excessive negative pressure in the vent will cause excessive draft; therefore, the draft regulator will open as a result of the higher atmospheric pressure on the exterior of the damper, allowing air to enter the vent and thereby increase the internal vent pressure. With excessive positive internal vent pressure, a double-acting regulator will open to relieve the pressure, lowering the vent internal pressure. 22 Copyright 2012, International Code Council

24 2012 North Carolina Fuel Gas Code Level II12/1/2017 Definitions Bonding Jumper – A conductor installed to electrically connect metallic gas piping to the grounding electrode system. This term is used in Section relative to the bonding of gas piping systems. It is a number 6 AWG or larger copper conductor or equivalent that is used to electrically bond gas piping to the grounding electrodes that are a part of the electrical service for the structure. 24 Copyright 2012, International Code Council

25 2012 North Carolina Fuel Gas Code Level II12/1/2017 Definitions Counter Appliances – Appliances such as coffee brewers and coffee urns and any appurtenant water-heating appliance, food and dish warmers, hot plates, griddles, waffle bakers and other appliances designed for installation on or in a counter. Counter appliances are small low-energy-input appliances and need not be vented unless the aggregate input rating of all the appliances exceeds that allowed in Section 25 Copyright 2012, International Code Council

26 2012 North Carolina Fuel Gas Code Level II12/1/2017 Definitions Exhaust Air – Air being removed from any space or piece of equipment or appliance and conveyed directly to the atmosphere. Exhaust air may be from a space, an appliance or a piece of equipment. Exhaust air systems are terminated outside of the building, in some cases after the exhaust air has been treated to remove any harmful emissions. Exhaust air is not recirculated. 26 Copyright 2012, International Code Council

27 2012 North Carolina Fuel Gas Code Level II12/1/2017 Definitions Draft – The pressure difference existing between the appliance or any component part and the atmosphere, that causes a continuous flow of air and products of combustion through the gas passages or he appliance to the atmosphere. Draft is the negative static pressure measured relative to atmospheric pressure that is developed in chimneys and vents and in the flue-ways of fuel-burning appliances. Draft can be produced by hot flue-gas buoyancy (“stack effect”), mechanically by fans and exhausters or by a combination of both natural and mechanical means. 27 Copyright 2012, International Code Council

28 2012 North Carolina Fuel Gas Code Level II12/1/2017 Definitions Draft: Mechanical or induced draft – The pressure difference created by the action of a fan, blower or ejector that is located between the appliance and the chimney or vent termination. Draft: Natural draft - The pressure difference created by a vent or chimney because of its height, and the temperature difference between the flue gases and the atmosphere. Mechanical or induced draft - Induced draft systems use a fan or blower to boost or “induce” draft in a venting system that produces insufficient natural draft. Draft induction implies that the combustion gases are “pulled” through a passageway or conduit. Draft inducers produce negative pressures on the inlet (upstream) side of the fan or blower. They are separate field-installed units located between an appliance and its venting system. Draft inducers are used with natural draft venting systems to overcome the resistance of vent or chimney connectors and to compensate for the inability of the chimney or vent to produce sufficient and reliable draft. Natural draft - Natural draft systems do not use mechanical devices such as fans or blowers, but instead rely on the principle of buoyancy to carry the products of combustion to the atmosphere. Because of the difference in temperature and the resultant difference in density between the hot products of combustion and the ambient atmosphere, the gases within the chimney or flue will rise, creating a buoyant “draft.” The phenomenon of natural draft is sometimes referred to as “stack effect” and is measured in inches of water column (kPa). The amount of draft is affected by the height of the chimney or vent and also by the ability of the chimney or vent to maintain the temperature differential between the combustion gases and the ambient air. 28 Copyright 2012, International Code Council

29 2012 North Carolina Fuel Gas Code Level II12/1/2017 Definitions Equipment – Apparatus and devices other than appliances. Exterior Masonry Chimneys – Masonry chimneys exposed to the outdoors on one or more sides below the roof line. Equipment - The term “equipment” does not refer to or describe anything that is defined as an “Appliance,” despite the fact that some appliances are commonly referred to in the field as “pieces of equipment.” The term “equipment” includes control devices, pressure regulators, valves, appliance appurtenances, gas connectors, power exhausters and a multitude of other devices that do not fit the description of “appliance.” Exterior Masonry Chimneys - The part of a chimney that extends above the roof will obviously be exposed to the outdoors, but some of the sizing methods in Section 504 are based on the chimney being indoors below the roof. If any one wall or multiple walls of a chimney are exposed to the outdoors, the chimney will be hard to warm up, will lose heat more rapidly, will likely produce condensation internally and may fail to produce the required draft. Some tables in Section 504 are specific to exterior masonry chimneys. 29 Copyright 2012, International Code Council

30 2012 North Carolina Fuel Gas Code Level II12/1/2017 Definitions Gas Appliance Regulator – A pressure regulator for controlling pressure to the manifold appliance. Types of appliance regulators are as follows: Adjustable. Multistage. Nonadjustable. These regulators are integral to the appliance and serve to stabilize the appliance input pressure and supply fuel gas to the appliance at the desired pressure. Most appliances come equipped with appliance regulators because the appliances are designed to operate at a pressure lower than the delivery pressure, even when low pressure gas [0.5 psig or lower (3.4 kPa)] is supplied. 30 Copyright 2012, International Code Council

31 2012 North Carolina Fuel Gas Code Level II12/1/2017 Definitions Labeled – Appliances, equipment, material or products to which have been affixed a label, seal, symbol or other identifying mark of a nationally recognized testing laboratory, inspection agency or other organization concerned with product evaluation that maintains periodic inspection of the product of the above-labeled items and whole labeling indicates either that the appliance, equipment, material or product meets identified standards or has been tested and found suitable for a specified purpose. North Carolina-specific: Laboratories, agencies or organizations that have been identified by approval and accreditation bodies, such as ANSI, IAS, ICC or OSHA, are acceptable. 31 Copyright 2012, International Code Council

32 2012 North Carolina Fuel Gas Code Level II12/1/2017 Definitions Listed – Appliances, equipment, materials, products or services included in a list published by a organization acceptable to the code official and concerned with evaluation of products or services that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services and whose listing states either that the appliance, equipment, material, product or service meets identified standards or has been tested and found suitable for a specified purpose. North Carolina-specific: Laboratories, agencies or organizations that have been identified by approval and accreditation bodies, such as ANSI, IAS, ICC or OSHA, are acceptable. 32 Copyright 2012, International Code Council

33 2012 North Carolina Fuel Gas Code Level II12/1/2017 Definitions Outlet – The point at which a gas-fired appliance connects to the gas piping system. Piping System – All fuel piping, valves and fittings from the outlet of the point of delivery to the outlets of the appliance shutoff valves. Outlet - A gas outlet is analogous to an electrical receptacle outlet. See Section for requirements covering the location of gas piping outlets. Piping System - A piping system includes tubing, pipe, fittings, valves and line pressure regulators used to convey fuel gas from the point of delivery to the appliance. This definition was revised to state that the piping system ends at the outlets of the appliance shutoff valves. This revision allows the last 6 feet (1829 mm) or less of gas conduit between the shutoff valve and the appliance inlet connection to be sized as a connector. Copyright 2012, International Code Council

34 2012 North Carolina Fuel Gas Code Level II12/1/2017 Definitions Room Large in Comparison with Size of the Appliance – Rooms having a volume equal to at least 12 times the total volume of a furnace, water heater or air-conditioning appliance and at least 16 times the total volume of a boiler. Total volume of the appliance is determined from exterior dimensions and is to include fan compartments and burner vestibules, when sued. When the actual ceiling height of a room is greater than 8 feet, the volume of the room is figured on the basis of a ceiling height of 8 feet. This definition deals with providing adequate space for installing heat-producing appliances, primarily for the prevention of excessive heat build-up and high temperatures. In rooms that satisfy this definition, appliances may be installed with clearances required by the listing and in accordance with the manufacturers’ installation instructions. Equipment may be installed in smaller rooms, alcoves and closets if the listing specifically states approval for such an installation and clearances are not reduced as would otherwise be allowed by Section 308. 34 Copyright 2012, International Code Council

35 Activity: Definition Matching2012 North Carolina Fuel Gas Code Level II 12/1/2017 Activity: Definition Matching Column A Column B Piping System The pressure difference created by a vent or chimney because of its height, and the temperature difference between the flue gases and the atmosphere. Bonding Jumper Equipment, material or product with an identified mark or nationally recognized testing laboratory. Natural Draft Chimney exposed to the outdoors on one or more sides. Exterior Masonry Chimneys The point at which a gas-fired appliance connects to the gas piping system. Labeled The fuel piping, valves and fittings from the outlets to the shutoff valves. Outlet A conductor installed to connect the gas piping to the electrode system. 35 Copyright 2012, International Code Council

37 Chapter 3: General Regulations2012 North Carolina Fuel Gas Code Level II 12/1/2017 Chapter 3: General Regulations Chapter 3 governs the approval and installation of all equipment and appliances that make up part of the installations regulated by the IFGC. Chapter 3 contains requirements for the safe and proper installation of gas-fired equipment and appliances to help assure protection of life and property. 37 Copyright 2012, International Code Council

38 Section 304 Combustion, Ventilation and Dilution Air2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 304 Combustion, Ventilation and Dilution Air Methods for providing combustion air include: All indoor air (Section 304.5). All outdoor air (Section 304.6). Combination indoor and outdoor air (Section 304.7). Engineered design (Section 304.8). Mechanical combustion air supply (Section 304.9). The provisions of Section 304 describe requirements for the combustion air necessary for the complete combustion of fuel gas, dilution of flue gases, and ventilation of gas-fired appliances and the space in which they are installed. An inadequate combustion air supply to gas-fired appliances can compromise safety by causing incomplete combustion, resulting in appliance malfunction and production of excess carbon monoxide. 38 Copyright 2012, International Code Council

40 Section 304.5 Indoor Combustion Air2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Indoor Combustion Air There are two methods for determining the required room volume: Standard method (Section ). 50 cubic feet per 1,000 Btu/h of the appliance input rating Known air-infiltration-rate method (Section ). Use Equation 3-1 for appliances other than fan-assisted Use Equation 3-2 for fan-assisted appliances The required room volume is determined by two methods: one method based on the actual air infiltration rate of the building and the other based on the familiar fixed ratio of 50 ft3 per 1000 Btu/h. Air taken directly from inside the building is an acceptable source of combustion air if a sufficient volume of air is available for the appliances served and the building construction allows sufficient infiltration. The provisions of this section rely on building envelope infiltration as the only source of combustion air. 40 Copyright 2012, International Code Council

41 Section 304.5.1 Standard Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Standard Method This is the optional default method intended for use when the ACH rate is unknown. If the actual ACH rate is known to be greater than 0.40, the method of Section will yield smaller required volumes. If the ACH rate is known to be less than 0.40, this method must not be used because it is based on an assumed ACH rate of at least The rate of 50 ft3/1,000 Btu/h (4.8 m3/kW) is a carryover from the previous editions of the code and was used for buildings that were not of unusually tight construction. 41 Copyright 2012, International Code Council

42 Section 304.5.2 Known Air-infiltration-rate Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Known Air-infiltration-rate Method This method considers the actual or calculated ACH rate and requires space volumes to be commensurate with that rate. This method can also be used when the ACH rate is unknown by simply picking a conservative ACH rate (0.40 ACH or less) representing the lowest anticipated ACH rate for the given building. 42 Copyright 2012, International Code Council

43 Section 304.5.2 Known Air-infiltration-rate Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Known Air-infiltration-rate Method For appliances other than fan-assisted, calculate volume using Equation 3-1. 43 Copyright 2012, International Code Council

44 Section 304.5.2 Known Air-infiltration-rate Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Known Air-infiltration-rate Method For fan-assisted appliances, calculate volume using Equation 3-2. where: Iother = All appliances other than fan assisted (input in Btu/h). Ifan = Fan-assisted appliance (Btu/h). ACH = Air change per hour 44 Copyright 2012, International Code Council

45 Section 304.5.3 Indoor Opening Size and Location2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Indoor Opening Size and Location This section prescribes the size and location of openings used to conjoin (couple) spaces for the purpose of increasing the available volume. Sections and prescribe the size and location of openings used to conjoin (couple) spaces for the purpose of increasing the available volume. The last sentence of Section speaks of this. These openings must be permanently open, except where interlocked motorized dampers are used in accordance with Section 45 Copyright 2012, International Code Council

48 Indoor Combustion Air Calculation2012 North Carolina Fuel Gas Code Level II 12/1/2017 Indoor Combustion Air Calculation Step 1 Starting with the fan-assisted boilers, use Section , Equation 3-2 to calculate the required volume for each boiler. 48 Copyright 2012, International Code Council

49 Indoor Combustion Air Calculation2012 North Carolina Fuel Gas Code Level II 12/1/2017 Indoor Combustion Air Calculation Step 2 Use Section , Equation 3-1 to calculate the required volume for each water heater. 49 Copyright 2012, International Code Council

50 Indoor Combustion Air Calculation2012 North Carolina Fuel Gas Code Level II 12/1/2017 Indoor Combustion Air Calculation Step 3 Total the volumes required for all appliances. Boiler 1 5,350 Boiler 2 Water heater 1 4.500 + Water heater 2 4,500 19,700 ft3 50 Copyright 2012, International Code Council

51 Indoor Combustion Air Calculation2012 North Carolina Fuel Gas Code Level II 12/1/2017 Indoor Combustion Air Calculation Step 4 Determine available (actual) volume in the building. Basement volume 48 ft x 25 ft x 9 ft = 10,800 ft3 Grade-floor volume + 21,600 ft3 Basement volume < Required volume 10,800 ft2 < 19,700 ft2 Therefore, for inside air to work, the volume of spaces on the two floors will have to be checked in accordance with Section 51 Copyright 2012, International Code Council

52 Indoor Combustion Air Calculation2012 North Carolina Fuel Gas Code Level II 12/1/2017 Indoor Combustion Air Calculation Step 5 Determine if louvered door opening area is adequate. In accordance with Section , a wood-louvered door will have 25 percent free area. Determine the actual louvered opening area. 30 in x 72 in = 2,160 in2 x 0.25 = 540 in2 In accordance with Section , a minimum free area of 2 in2/1,000 Btu/h of appliance input is required. Determine the required area. 52 Copyright 2012, International Code Council

53 Indoor Combustion Air Calculation2012 North Carolina Fuel Gas Code Level II 12/1/2017 Indoor Combustion Air Calculation Solution The combined volumes of both stories is greater than required. However, the louvered door opening area connecting the stories is inadequate. Possible solutions include adding outdoor openings in accordance with Section or providing metal louvers in the door instead of wood. 53 Copyright 2012, International Code Council

54 Section 304.6 Outdoor Combustion Air2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Outdoor Combustion Air Describes two methods for supplying combustion air from the outdoors: The traditional methods of two direct openings or duct to the outdoors. A newer method using one opening or duct to the outdoors. Spaces that are naturally ventilated with outdoor air, such as attics or crawl spaces, are considered as an acceptable alternative to a direct connection to the outdoors. This section describes two methods for supplying combustion air from the outdoors: the traditional method of two direct openings or ducts to the outdoors and a newer method using one opening or duct to the outdoors. 54 Copyright 2012, International Code Council

55 Section 304.6.1 Two-permanent-openings Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Two-permanent-openings Method Two openings are intended to: Induce a convective air current in the room or space by admitting cooler, denser air in the lower opening. Allowing the escape of warmer, less dense air through the upper opening. Two openings located as prescribed in this section are intended to induce a convective air current in the room or space by admitting cooler, denser air in the lower opening and allowing the escape of warmer, less dense air through the upper opening. The farther apart the openings, the greater the temperature differential and the greater the convective force behind the current. A component of combustion air is cooling (ventilation) air for the appliance enclosure. The two-opening method was created to ventilate the appliance enclosure in addition to supplying combustion air. This ventilation cools the appliances and would help remove any combustion gases that spilled from the appliances. 55 Copyright 2012, International Code Council

58 Outdoor Combustion Air Calculation2012 North Carolina Fuel Gas Code Level II 12/1/2017 Outdoor Combustion Air Calculation NEED EXAMPLE All Air From Outdoors 58 Copyright 2012, International Code Council

59 Section 304.6.2 One-permanent-opening Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section One-permanent-opening Method Works as well as the tradition two-opening method. Depends on a reduced pressure being created in the enclosure by the draft created by the venting system. This reduced pressure causes combustion air to enter the enclosure through the single opening. This method allows for fewer openings, fewer ducts, and fewer objections by the owners of occupants. Research has shown that for modern appliances, a single opening to the outdoors will perform as well as the traditional two-opening method. The one-opening method described in this section depends on a reduced pressure being created in the enclosure by the draft created by the venting system. This reduced pressure causes combustion air to enter the enclosure through the single opening. The opening must be properly sized considering both sizing criteria: the square-inch-area-per-Btu/h ratio and the area minimum based on the sum of the areas of all vent connectors in the enclosure. This method allows for fewer openings, fewer ducts and fewer objections by the owners/occupants. 59 Copyright 2012, International Code Council

61 Section 304.7 Combination Indoor and Outdoor Combustion Air2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Combination Indoor and Outdoor Combustion Air This method is a combined application of Section and Section and allows credit for the amount of infiltration that exists and makes up for the shortage with supplemental outdoor air. This method of supplying combustion air is a combined application of Section and Section This method allows credit for the amount of infiltration that exists and makes up for the shortage with supplemental outdoor air. In other words, in addition to obtaining combustion air directly from the outdoors, this method relies on building infiltration for a portion of the total combustion air. In spaces where the volume is insufficient to satisfy the method of Section or where smaller outdoor air openings than required by Section are desired, this method allows infiltration and outdoor openings to supplement each other. If the appliances are enclosed in a small room such as a closet, openings to adjacent spaces as prescribed by Section must be provided to couple the appliance room volume with any other space volume counted on to provide combustion air. Frequently, sufficient volume cannot be obtained in the appliance enclosure or by opening the appliance enclosure to adjacent spaces. This method of combining indoor and outdoor air is an alternative solution. Simply stated, this section uses ratios of what is required to what is actually supplied so that when combined, the indoor air component and the outdoor air component add up to the whole required. 61 Copyright 2012, International Code Council

62 Combined Indoor/Outdoor Combustion Air Calculation2012 North Carolina Fuel Gas Code Level II 12/1/2017 Combined Indoor/Outdoor Combustion Air Calculation Determine the factors for indoor and outdoor combustion air in the room displayed. A combination of indoor and outdoor combustion air is to be provided for two natural draft boilers. The air infiltration rate is not known. 62 Copyright 2012, International Code Council

63 Combined Indoor/Outdoor Combustion Air Calculation2012 North Carolina Fuel Gas Code Level II 12/1/2017 Combined Indoor/Outdoor Combustion Air Calculation 63 Copyright 2012, International Code Council

64 Combined Indoor/Outdoor Combustion Air Calculation2012 North Carolina Fuel Gas Code Level II 12/1/2017 Combined Indoor/Outdoor Combustion Air Calculation In accordance with Section , the required volume of the room containing the boilers would be 50 cubic feet per 1,000 Btu/h of the applied input rating. The actual room volume is 20 ft x 50 ft x 8 ft = 8,000 ft3 64 Copyright 2012, International Code Council

65 Combined Indoor/Outdoor Combustion Air Calculation2012 North Carolina Fuel Gas Code Level II 12/1/2017 Combined Indoor/Outdoor Combustion Air Calculation In accordance with Section , Item 1: The ratio of interior spaces shall be the available volume of all communicating spaces divided by the required volume. Determine the ratio of available (actual) volume to the required volume. Actual Volume 8,000 ft3 Required Volume 9,000 ft3 = 0.89 65 Copyright 2012, International Code Council

66 Combined Indoor/Outdoor Combustion Air Calculation2012 North Carolina Fuel Gas Code Level II 12/1/2017 Combined Indoor/Outdoor Combustion Air Calculation In accordance with Section , Item 2: The outdoor size reduction factor shall be one minus the ratio of interior spaces. Determine the outdoor opening size reduction factor. 1 – 0.89 = 0.11 66 Copyright 2012, International Code Council

67 Combined Indoor/Outdoor Combustion Air Calculation2012 North Carolina Fuel Gas Code Level II 12/1/2017 Combined Indoor/Outdoor Combustion Air Calculation In accordance with Section , Item 3: The minimum size of outdoor opening(s) shall be the full size of outdoor opening(s) calculated in accordance with Section 304.6, multiplied by the reduction factor. The minimum dimension of the openings shall not be less than 3 inches. Determine the size of the outdoor opening required as if all combustion air is to be supplied via the outdoor opening. 67 Copyright 2012, International Code Council

68 Combined Indoor/Outdoor Combustion Air Calculation2012 North Carolina Fuel Gas Code Level II 12/1/2017 Combined Indoor/Outdoor Combustion Air Calculation Since a single high opening is provided in an exterior wall, Section applies and would required an area of 1 in 2/3,000 Btu/h of total appliance input rating [assuming 6-inch vent connectors, the total area of the boiler vent connectors is 56.5 in2]. 68 Copyright 2012, International Code Council

69 Combined Indoor/Outdoor Combustion Air Calculation2012 North Carolina Fuel Gas Code Level II 12/1/2017 Combined Indoor/Outdoor Combustion Air Calculation Solution The actual required size of the outdoor air opening is 60 in2 x 0.11 = 6.6 in2. Since the minimum dimensions must be not less than 3 inches, the minimum area must be 9 in2. 69 Copyright 2012, International Code Council

70 Section 304.9 Mechanical Combustion Air Supply2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Mechanical Combustion Air Supply This method supplies combustion air by means of a fan/blower that runs when any of the served appliances are in a firing cycle. The fan/blower must be sized to supply the required airflow based on the simultaneous operation of all appliances that are served by the fans/blowers. This method supplies combustion air by means of a fan/blower that runs when any of the served appliances are in a firing cycle. The fan/blower must be sized to supply the required airflow based on the simultaneous operation of all appliances that are served by the fans/blowers. The total Btu/h input rating of all fuel-burning appliances located in the room or space must be used because the potential exists for all of the appliances to be operating at the same time. This method is used where gravity openings to the outdoors are impractical or undesirable. A small fan-powered intake opening can substitute for comparatively large gravity openings, especially where freezing temperatures are a problem or there is no room for the required size gravity openings. 70 Copyright 2012, International Code Council

72 Section 307 Condensate Disposal2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 307 Condensate Disposal Section 307 recognizes that gas-fired space heating appliances are commonly part of space cooling and conditioning systems and the condensate drainage provisions of the IMC are applicable. Condensate relative to combustion of fuel gas and condensate produced by refrigeration and cooling coils are addressed. This section recognizes that gas-fired space heating appliances are commonly part of space cooling and conditioning systems and the condensate drainage provisions of the IMC are applicable. Sections through address condensate relative to combustion of fuel gas, whereas, this section addresses condensate produced by refrigeration and cooling coils. 72 Copyright 2012, International Code Council

73 Section 308 Clearance Reduction for Unlisted Equipment2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 308 Clearance Reduction for Unlisted Equipment Heat-producing appliances and mechanical equipment, such as chimneys, vents, appliances, devices and equipment must be installed with the required minimum clearances to combustible materials indicated by their listing label. Heat-producing appliances and mechanical equipment must be installed with the required minimum clearances to combustible materials indicated by their listing label. It is not uncommon to encounter practical or structural difficulties in maintaining clearances. 73 Copyright 2012, International Code Council

74 Section 308 Clearance Reduction for Unlisted Equipment2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 308 Clearance Reduction for Unlisted Equipment Clearance reduction methods have been developed to allow, in some cases, reduction of the minimum prescribed clearance distance while achieving equivalent protection. 74 Copyright 2012, International Code Council

78 2012 North Carolina Fuel Gas Code Level II12/1/2017 Activity: Chapter 3 In each of these scenarios, are the code requirements met? A water heater is located in a closet that is accessed through a bathroom. All combustion air is taken from the building interior in full compliance with Section 78 Copyright 2012, International Code Council

79 2012 North Carolina Fuel Gas Code Level II12/1/2017 Activity: Chapter 3 A wall-mounted, unvented room heater is installed in a bedroom with exterior walls. The heater has an oxygen depletion safety shutoff device and the bedroom has the volume required by Section The input rating of the heater is 11,000 Btu/hr. 79 Copyright 2012, International Code Council

81 Chapter 4: Gas Piping Installations2012 North Carolina Fuel Gas Code Level II 12/1/2017 Chapter 4: Gas Piping Installations Chapter 4 regulates the design and installation of fuel-gas distribution piping and systems from the point of delivery of the fuel gas to the appliances and equipment that consume the fuel. The intent is to minimize the hazards associated with the use and distribution of highly flammable/explosive fuel gases. This chapter is intended to regulate the design and installation of fuel-gas distribution piping and systems from the point of delivery of the fuel gas to the appliances and equipment that consume the fuel. The intent is to minimize the hazards associated with the use and distribution of highly flammable/explosive fuel gases. 81 Copyright 2012, International Code Council

82 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section Scope This chapter and Appendix A regulate aspects of fuel-gas distribution systems, including: Design. Installation. Testing. Repair and maintenance. These provisions do not apply to components owned by the serving gas utility company but extend from the point of delivery to the appliances. Utility piping systems located within buildings must meet the provisions of the IBC. 82 Copyright 2012, International Code Council

85 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section 402 Pipe Sizing Gas piping systems must be sized to allow full simultaneous utilization of all the appliances in the plan. Undersized gas piping systems are not capable of delivering the required volume of fuel at the required pressure. Inadequate gas pressure can cause hazardous operation of appliances, including incomplete combustion, burner malfunction and flashback, and appliance malfunction and damage. 85 Copyright 2012, International Code Council

86 Gas Piping System Plan Review2012 North Carolina Fuel Gas Code Level II 12/1/2017 Gas Piping System Plan Review The first time gas piping systems are examined for compliance with the code is at plan review. Steps to determine if the system is sized correctly using the table sizing method are: Step 1: Determine maximum gas demand. Step 2: Determine length to most remote outlet. Step 3: Select the correct table. Step 4: Locate gas-demand figures. Step 5: Locate nominal size of pipe required. 86 Copyright 2012, International Code Council

89 Section 402.4 Sizing Tables and Equations2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Sizing Tables and Equations Determine the pipe length using one of the following table sizing methods: Longest length method (Section ) Branch length method (Section ) Hybrid pressure (Section ) The length of pipe or tube to be used with the tables and equations is determined by the sizing method being used. Section involves only one length whereas Sections and involve multiple lengths. 89 Copyright 2012, International Code Council

90 Section 402.4 Sizing Tables and Equations2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Sizing Tables and Equations There are 28 tables in Chapter 4 to help determine sizing of gas piping. There are five variables to take into account: The type of fuel gas. The specific gravity of the gas. The gas supply pressure. The pressure drop indicated. The piping material used. 90 Copyright 2012, International Code Council

91 Section 402.4.1 Longest Length Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Longest Length Method The longest length method is based on the most demanding circuit (longest run) and compensates for pressure losses throughout the entire system. The maximum pipe length from the point of delivery to the farthest outlet is determined, including any allowance for the equivalent length of fittings. This section provides a step-by-step approach to proper application of the tables using the traditional longest-length method. When using the tables, the maximum pipe length from the point of delivery to the farthest outlet must be determined, including any allowance for the equivalent length of fittings. The designer will use the row in the table that equals the determined length or the next higher row if the determined length is between table values. The system will be designed using only values taken from this row. This is known as the longest-run method: Basing the sizing on the most demanding circuit (longest run) compensates for pressure losses throughout the entire system. 91 Copyright 2012, International Code Council

92 Example: Longest Length Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example: Longest Length Method Determine the required pipe size of each section and outlet of the piping system shown, with a designated pressure drop of 0.5-inch w.c. The gas to be used has 0.60 specific gravity and a heating value of 1,000 Bth/ft3 92 Copyright 2012, International Code Council

94 Example: Longest Length Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example: Longest Length Method Solution (2) The length of pipe from the point of delivery to the most remote outlet (A) is 60 feet. This is the only distance used. (3) Using the row marked 60 feet in Table 402.4(2): (a) Outlet A, supplying 35 cfh, requires ½-inch pipe. (b) Outlet B, supplying 75 cfh, requires ¾-inch pipe. 94 Copyright 2012, International Code Council

95 Example: Longest Length Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example: Longest Length Method Solution (cont.) (3) Using the row marked 60 feet in Table 402.4(2) (cont.): (c) Section 1, supplying Outlets A and B, or 110 cfh, requires ¾-inch pipe. (d) Section 2, supplying Outlets C and D, or 135 cfh, requires ¾-inch pipe. (e) Section 3, supplying Outlets A, B, C and D, or 245 cfh, requires 1-inch pipe. 95 Copyright 2012, International Code Council

96 Example: Longest Length Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example: Longest Length Method Solution (4) If a different gravity factor is applied to this example, the values in the row marked 60 feet of Table 402.4(2) would be multiplied by the appropriate multiplier from Table A.2.4 and the resulting cubic feet per hour values would be used to size the piping. 96 Copyright 2012, International Code Council

97 Section 402.4.2 Branch Length Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Branch Length Method The branch length method is a variation of the longest-length method. This method involves multiple piping lengths within a system for application of the tables or equations, whereas the longest-length method involves only one piping length per system. Pipe size of each section of the longest pipe run from the point of delivery to the most remote outlet to be determined using the longest run of piping and the load of the section. This sizing method is a variation of the longest-length method, and the results can be less conservative. Because less headroom is built into this method, it is especially important to account for the equivalent length of fittings installed in the system. This method involves multiple piping lengths within a system for application of the tables or equations, whereas the longest-length method involves only one piping length per system. 97 Copyright 2012, International Code Council

98 Section 402.4.2 Branch Length Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Branch Length Method The pipe size of each section of branch piping not previously sized to be determined using the length of piping from the point of delivery to the most remote outlet in each branch and the load of the section. 98 Copyright 2012, International Code Council

99 Example: Branch Length Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example: Branch Length Method Determine the required semi-rigid copper tubing size of each section of the piping system shown, with a designated pressure drop of 1-inch w.c. The gas to be used has 0.60 specific gravity and a heating value of 1,000 Btu/ft3. 99 Copyright 2012, International Code Council

100 Example: Longest Branch Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example: Longest Branch Method Solution (1) Section A (a) The length of tubing from the point of delivery to the most remote appliance is 50 feet, A + C. (b) Use this longest length to size Sections A and C. (c) Using the row marked 50 feet in Table 402.4(8), Section A, supplying 220 cfh for four appliances requires 1-inch tubing. 100 Copyright 2012, International Code Council

101 Example: Longest Branch Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example: Longest Branch Method Solution (2) Section B (a) The length of tubing from the point of delivery to the range/oven at the end of Section B is 30 feet, A + B. (b) Use this branch length to size Section B only. (c) Using the row marked 30 feet in Table 402.4(8), Section B, supplying 75 cfh for the range/oven requires ½-inch tubing. 101 Copyright 2012, International Code Council

102 Example: Longest Branch Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example: Longest Branch Method Solution (3) Section C (a) The length of tubing from the point of delivery to the dryer at the end of Section C is 50 feet, A + C. (b) Use this branch length (which is also the longest length) to size Section C. (c) Using the row marked 50 feet in Table 402.4(8), Section C, supplying 30 cfh for the dryer requires 3/8-inch tubing. 102 Copyright 2012, International Code Council

103 Example: Longest Branch Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example: Longest Branch Method Solution (4) Section D (a) The length of tubing from the point of delivery to the water heater at the end of Section D is 30 feet, A + D. (b) Use this branch length to size Section D only. (c) Using the row marked 30 feet in Table 402.4(8), Section D, supplying 35 cfh for the water heater requires 3/8-inch tubing. 103 Copyright 2012, International Code Council

104 Example: Longest Branch Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example: Longest Branch Method Solution (5) Section E The length of tubing from the point of delivery to the furnace at the end of Section E is 30 feet, A + E. Use this branch length to size Section E only. Using the row marked 30 feet in Table 402.4(8), Section E, supplying 80 cfh for the furnace requires ½-inch tubing. 104 Copyright 2012, International Code Council

105 Section 402.4.3 Hybrid Pressure2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Hybrid Pressure Hybrid pressure piping systems convey gas at different pressures in different parts of the system. One or more pressure regulators are used to reduce the pressure in portions of the system. Hybrid pressure piping systems convey gas at different pressures in different parts of the system. One or more pressure regulators are used to reduce the pressure in portions of the system. In some cases, a single gas piping system must deliver widely varying pressure to loads throughout a building. The most common hybrid pressure systems allow small economically sized piping to carry large loads over long distances by conveying gas at high pressures. Near the load being supplied, pressure regulators reduce the higher pressure to suit the load. 105 Copyright 2012, International Code Council

108 Example 1: Hybrid Pressure2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example 1: Hybrid Pressure Step 1 Using Table 402.4(5), determine the minimum required size of piping Sections A through D. The longest run of piping from the point of delivery to the most remote regulator is 175 feet. Section A serves a load of 625 MBH and in the 175-foot row of the table, ½-inch pipe is shown to have a capacity of 728 ft3/hr or 728,000 Btu/hr for gas with a heating value of 1,000 Btu/ft3. 108 Copyright 2012, International Code Council

109 Example 1: Hybrid Pressure2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example 1: Hybrid Pressure Step 1 (continued) Because Sections B, C and D all serve lesser loads than Section A, they too can be ½ inch in size. Because Table 402.4(5) is based upon a pressure drop of 3.5 psi, the available pressure at the inlets of the “pounds-to-inches” regulators under full load condition will be at least 1.5 psig. 109 Copyright 2012, International Code Council

110 Example 1: Hybrid Pressure2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example 1: Hybrid Pressure Step 2 Determine size of piping Sections E, F and G, using Table 402.4(2) and the longest length of piping from the pounds-to-inches regulator to the most remote outlet. In this case, rooftop unit 1 is the most remote at 65 feet from the regulator. 110 Copyright 2012, International Code Council

111 Example 1: Hybrid Pressure2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example 1: Hybrid Pressure Step 3 Determine size of piping Sections H, I and J in the same manner described in Item 2, above. NOTE: MBH = 1,000 Btu/h 111 Copyright 2012, International Code Council

112 Example 2: Hybrid Pressure2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example 2: Hybrid Pressure Hybrid Pressure Parallel Distribution System 112 Copyright 2012, International Code Council

113 Example 2: Hybrid Pressure2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example 2: Hybrid Pressure GIVEN: All piping is CSST. Piping branches run in parallel. Individual CSST appliance branch runs supplied by manifold. Supply pressure is 2 psi downstream of meter. Chosen pressure drop is 1 psi for Section A. Natural gas with specific gravity of 0.60. Heating value of gas is 1,000 Btu/ft3. Supply pressure at manifold is 8 inches wc. 113 Copyright 2012, International Code Council

114 Example 2: Hybrid Pressure2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example 2: Hybrid Pressure GIVEN: Chosen pressure drop is 3 inches wc for Sections B through G. Appliances need 5 inches wc minimum supply pressure. Pressure drop across regulator is less than ½ psi at full load of this system. 114 Copyright 2012, International Code Council

115 Example 2: Hybrid Pressure2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example 2: Hybrid Pressure Sizing Section A: Size Section A based on total load and length from meter to regulator. Total load = = 221 cfh. Section length = 45 feet. Use Table 402.4(6). 115 Copyright 2012, International Code Council

116 Example 2: Hybrid Pressure2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example 2: Hybrid Pressure Sizing Section B: Size Section B based on appliance load and length from regulator to appliance. Appliance load = 80 cfh. Section length (furnace) = 15 feet. Use Table 402.4(13). 116 Copyright 2012, International Code Council

117 Example 2: Hybrid Pressure2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example 2: Hybrid Pressure Sizing Section C: Size Section C based on appliance load and length from regulator to appliance. Total load = 36 cfh. Section length (water heater) = 10 feet. Use Table 402.4(13). 117 Copyright 2012, International Code Council

118 Example 2: Hybrid Pressure2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example 2: Hybrid Pressure Sizing Section D: Size Section D based on appliance load and length from regulator to appliance. Total load = 52 cfh. Section length (range) = 20 feet. Use Table 402.4(13). 118 Copyright 2012, International Code Council

119 Example 2: Hybrid Pressure2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example 2: Hybrid Pressure Sizing Section E: Size Section E based on appliance total load and length from regulator to farthest appliance. Total load = = 53 cfh. Section length (dryer/room heater) = = 25 feet. Use Table 402.4(13). 119 Copyright 2012, International Code Council

120 Example 2: Hybrid Pressure2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example 2: Hybrid Pressure Sizing Section F: Size Section F based on appliance total load and length from regulator to farthest appliance. Total load (dryer) = 28 cfh. Section length = = 25 feet. Use Table 120 Copyright 2012, International Code Council

121 Example 2: Hybrid Pressure2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example 2: Hybrid Pressure Sizing Section G: Size Section G based on appliance total load and length from regulator to farthest appliance. Total load (room heater) = 25 cfh. Section length = = 25 feet. Use Table 402.4(13). 121 Copyright 2012, International Code Council

122 Review of the Sizing Tables2012 North Carolina Fuel Gas Code Level II 12/1/2017 Review of the Sizing Tables Schedule 40 Metallic Pipe Natural Gas Undiluted Propane Semi-rigid Copper Tubing Corrugated Stainless Steel Tubing (CSST) 122 Copyright 2012, International Code Council

123 Review of the Sizing Tables2012 North Carolina Fuel Gas Code Level II 12/1/2017 Review of the Sizing Tables Polyethylene Plastic Pipe Natural Gas Undiluted Propane Polyethylene Plastic Tubing Polyethylene Plastic Pipe Sizing Between First Stage and Second Stage Regulator Polyethylene Plastic Tube Sizing 123 Copyright 2012, International Code Council

124 Activity: Which Table Would You Use?2012 North Carolina Fuel Gas Code Level II 12/1/2017 Activity: Which Table Would You Use? A gas piping system using Schedule 40 steel piping with an identified pressure drop of 0.5 in wc; with a gas pressure of < 0.5 psi (< 3.4 kPa) and conveying a gas of 0.6 specific gravity. Table (2) 124 Copyright 2012, International Code Council

125 Activity: Which Table Would You Use?2012 North Carolina Fuel Gas Code Level II 12/1/2017 Activity: Which Table Would You Use? A gas piping system using Schedule 40 steel piping with an identified pressure drop of 1.0 psi (6.9 kPa), gas pressure of 2 psi(14 kPa) and conveying a gas of 0.7 specific gravity. Table 402.4(3) and Appendix Table A.2.4 125 Copyright 2012, International Code Council

126 Activity: Branch Length Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Activity: Branch Length Method Determine the minimum required size of the piping sections in this figure. Copyright 2012, International Code Council

127 Activity: Branch Length Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Activity: Branch Length Method Pipe to be sized as follows: Pipe size of each section of the longest pipe run from the point of delivery to the most remote outlet must be determined using the longest run of piping and the load of the section. 127 Copyright 2012, International Code Council

128 Activity: Branch Length Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Activity: Branch Length Method Pipe to be sized as follows (cont.): The pipe size of each section of branch piping not previously sized must be determined using the length of piping from the point of delivery to the most remote outlet in each branch and the load of the section. 128 Copyright 2012, International Code Council

129 Activity: Branch Length Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Activity: Branch Length Method GIVEN: Natural Gas Specific Gravity 0.60 Pressure drop 0.5 inches wc for steel pipe and 3 inches wc for CSST Supply pressure 9 inches 129 Copyright 2012, International Code Council

130 Activity: Branch Length Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Activity: Branch Length Method Using Table 402.4(2), size Sections A through G. 1¼” 1¼” 1” 1” ¾” ¾” ½” 130 Copyright 2012, International Code Council

131 Activity: Branch Length Method2012 North Carolina Fuel Gas Code Level II 12/1/2017 Activity: Branch Length Method Using Table 402.4(13), size Sections H through N. 13 23 15 18 15 18 13 131 Copyright 2012, International Code Council

132 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section 413 Compressed Natural Gas Motor Vehicle Fuel-dispensing Facilities This section, as well as the International Fire Code, regulates motor fuel-dispensing facilities for CNG fuel. 132 Copyright 2012, International Code Council

134 Chapter 5: Chimneys and Vents2012 North Carolina Fuel Gas Code Level II 12/1/2017 Chapter 5: Chimneys and Vents Chapter 5 contains provisions for the installation, maintenance, repair and approval of all residential and commercial chimney and venting systems that convey the products of combustion from fuel-burning appliances to the outdoors. These provisions are intended to minimize the hazards associated with the venting of combustion products produced by fuel-gas-fired appliances and equipment. The provisions in this chapter are intended to minimize the hazards associated with the venting of combustion products produced by fuel-gas-fired appliances and equipment. The requirements of this chapter are intended to achieve the complete removal of the products of combustion from vented fuel-gas-fired appliances and equipment. This chapter includes regulations for the proper selection, design, construction and installation of a chimney or vent, along with measures to minimize the related potential fire hazards. A chimney or vent must be designed for the type of appliance or equipment it serves. Chimneys and vents are designed for specific applications depending on the flue gas temperatures and the pressures at which the chimney or vent operates. The primary hazards associated with chimneys and vents are high temperatures and the chemical nature of combustion byproducts. 134 Copyright 2012, International Code Council

135 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section Scope Chapter 5, and Appendices B and C, govern the installation, maintenance, repair and approval of factory-built chimneys, chimney liners, vents and connectors and the utilization of masonry chimneys serving gas-fired appliances. Components serving appliances burning other than fuel gas are regulated by the International Mechanical Code. The construction, repair, maintenance and approval of masonry chimneys are regulated by the International Building Code. This section contains requirements for the installation, maintenance, repair and approval of residential, commercial and industrial chimney and venting systems that convey the products of combustion from a gas-fired appliance to the outside atmosphere. Venting systems for fuel-fired appliances other than gas-fired appliances, such as oil and solid-fuel appliances, are covered in International Mechanical Code. The construction of masonry chimneys is regulated by Chapter 21 of the International Building Code. 135 Copyright 2012, International Code Council

136 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section General Section Appliances Not Required to be Vented Every appliance must discharge the products of combustion to the outdoors, except for: Ranges Built-in domestic cooking units listed and marked for optional venting. Hot plates and laundry stoves. Type I clothes dryers (Type I clothes dryers shall be exhausted in accordance with the requirements of Section 614). Appliances other than those listed in Section must be vented to convey the potentially harmful combustion byproducts to the outdoor atmosphere. 136 Copyright 2012, International Code Council

137 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section General Section Appliances Not Required to be Vented A single booster-type automatic instantaneous water heater, where designed and used solely for the sanitizing rinse requirements of a dishwashing machine, provided that the heater is installed in a commercial kitchen having a mechanical exhaust system. Refrigerators. Counter appliances. Room heaters listed for unvented use. 137 Copyright 2012, International Code Council

138 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section General Section Appliances Not Required to be Vented Direct-fired makeup air heaters. Other appliances listed for unvented use and not provided with flue collars. Specialized appliances of limited input such as laboratory burners and gas lights. 138 Copyright 2012, International Code Council

140 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section 502 Vents Vents regulated by this section are factory fabricated and must be listed and labeled. The labeling requirement applies to all components of the system, including: Sections of pipe. Fittings. Terminal caps. Supports. Spacers. Vents regulated by this section are factory fabricated and must be listed and labeled. The labeling requirement applies to all components of the system such as the sections of pipe, fittings, terminal caps, supports and spacers. The provision for unlisted plastic vents is necessary to allow for the venting systems commonly specified in the installation instructions for Category IV condensing appliances. Unlisted plastic pipe (commonly PVC or CPVC plumbing pipe) vents are distinct from listed high-temperature plastic special gas vents that were designed primarily for Category III appliances. Unlisted plastic pipe can be used only when specified by the appliance manufacturer and must be installed as directed in the appliance installation instructions. Unlisted plastic pipe is used only for high efficiency Category IV gas-fired appliances. The pipe functions as an exhaust pipe for combustion gases and as a combustion air intake pipe. 140 Copyright 2012, International Code Council

141 Types of Venting Systems2012 North Carolina Fuel Gas Code Level II 12/1/2017 Types of Venting Systems There are six types of venting systems: Type B Gas Vent. Type BW Gas Vent. Type L Vent. Chimney. Single-wall Metal Pipe. Plastic Pipe and Stainless-steel Special Venting Systems. 141 Copyright 2012, International Code Council

142 Section 502.7 Protection Against Physical Damage2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Protection Against Physical Damage This section requires protection from nail and screw penetration for vents in the same manner that the code protects gas piping and tubing. This section requires protection from nail and screw penetration for vents in the same manner that the code protects gas piping and tubing. Plastic and metal vent systems typically pass through or are enclosed by construction assemblies, thereby making them highly susceptible to penetration by fasteners. Such penetrations can damage the vent and the damage would not be visible in concealed locations. Possible results from vent penetration include cracking/splitting of pipe, leakage of condensate and/or combustion gases, corrosion failure of metals, structural decay, interference with required clearances and restraint of expansion and contraction movement. 142 Copyright 2012, International Code Council

144 Section 503 Venting of Appliances2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 503 Venting of Appliances The venting system must be able to withstand the temperature and pressure ranges generated by the appliance and to accommodate condensation, if necessary. This section is in itself commentary and does not state any requirements. Section 503 contains general sizing, design and installation requirements for venting systems. Section 504 covers vent system sizing for Category I appliances. 144 Copyright 2012, International Code Council

145 Section 503.3.4 Ventilating Hoods and Exhaust Systems2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Ventilating Hoods and Exhaust Systems This section addresses commercial occupancies such as restaurant kitchens where the kitchen exhaust system is used to vent gas-fired appliances such as booster water heaters for dishwashers. It requires the appliance and the ventilating hood or exhaust system to be interlocked to ensure simultaneous operation of the hood or exhaust system whenever the appliance is firing. This section addresses commercial occupancies such as restaurant kitchens where the kitchen exhaust system is used to vent gas-fired appliances such as booster water heaters for dishwashers. Commercial gas-fired appliances must be vented either by individual venting means such as Type B vents or exhausters, or by venting the products of combustion into the kitchen exhaust hood system that serves the appliances. This section requires the appliance and the ventilating hood or exhaust system to be interlocked to ensure simultaneous operation of the hood or exhaust system whenever the appliance is firing. 145 Copyright 2012, International Code Council

146 Section 503.3.5 Air Ducts and Furnace Plenums2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Air Ducts and Furnace Plenums Venting systems cannot extend into or pass through any fabricated air duct or furnace plenum. This is to eliminate the possibility that the venting system is subjected to negative or positive pressures and/or temperature extremes that could cause the venting system to deteriorate, fail to produce the required draft, produce condensations and/or leak combustion gases. If a vent or chimney or a connector passes through or extends into a duct or furnace plenum, it is possible to subject the venting system to negative or positive pressures and/or temperature extremes that could cause the venting system to deteriorate, fail to produce the required draft, produce condensation and/or leak combustion gases. A furnace plenum is a component of the ductwork system constructed as a junction box for multiple duct connections. The term “furnace plenum” is defined in Section 202 and the term “fabricated air duct” refers to factory-, shop- or site-built supply relief, exhaust and return air ducts and does not refer to nonducted building cavities and plenums, such as spaces above ceilings used to convey air. Section addresses nonducted interstitial spaces used as plenums. 146 Copyright 2012, International Code Council

147 Section 503.4 Type of Venting System to be Used2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Type of Venting System to be Used A mismatch between an appliance and a vent of chimney can result in a dangerous operating condition. Table identifies the type of venting system to be used with specific appliances. The table lists various types of vents and the corresponding types of appliances that can be served by the vents. The vent system must be tested and specifically approved for use with the approved appliance. If the vent system is not a tested and labeled component of the appliance, the material must be approved for use with the appliance and installed in accordance with the manufacturer’s installation instructions. 147 Copyright 2012, International Code Council

149 Section 503.5 Masonry, Metal and Factory-built Chimneys2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Masonry, Metal and Factory-built Chimneys Factory-built chimneys must be installed in accordance with the manufacturer’s installation instructions. Factory-built chimneys used to vent appliances that operate at a positive vent pressure must be listed for such application. Metal chimneys must be built and installed in accordance with NFPA 211. Factory-built chimneys - Prefabricated chimney systems must bear the label of an approved agency. A label is required on all components of the chimney system such as the pipe sections, shields, fireblocks, fittings, termination caps and supports. The label states information such as the type of appliance the chimney was tested for use with, a reference to the manufacturer’s installation instructions and the minimum required clearances to combustibles. Metal chimneys - This section addresses metal chimneys, which are often referred to as smokestacks. Metal chimneys are used primarily in industrial applications where the vent gases are very high temperature. Discharging high temperature vent gases is a waste of energy and is thus becoming increasingly rare. Note that metal chimneys are different than what the code refers to as factory-built chimneys. 149 Copyright 2012, International Code Council

150 Section 503.5 Masonry, Metal and Factory-built Chimneys2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Masonry, Metal and Factory-built Chimneys Masonry chimneys must be built and installed in accordance with NFPA 211 and be lined with approved clay flue lining, a listed chimney lining system or other approved material that will resist corrosion, erosion, softening or cracking from vent gases at temperatures up to 1,800°F. A chimney liner might be listed for use with solid-, liquid- and gas-fuel-fired appliances. The label required by this section is intended to warn the unknowing installer who sees a masonry chimney and thinks that it can serve a solid- or liquid-fuel-fired appliance. The label would be applicable to chimney liner systems that are designed for gas-fired appliances only. 150 Copyright 2012, International Code Council

151 Section 503.5.4 Chimney Termination2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Chimney Termination In order to prevent wind and pressure zones from reducing the amount of draft produced by the chimney, low-heat and residential-type chimneys must extend at least 3 feet above the roof, measured from the highest point of the roof penetration. They must also be at least 2 feet higher than any portion of the roof within a 10-foot horizontal distance. Low-heat and residential-type chimneys must extend at least 3 feet above the roof, measured from the highest point of the roof penetration. They must also be at least 2 feet higher than any portion of the roof within a 10-foot horizontal distance. 151 Copyright 2012, International Code Council

152 2012 North Carolina Fuel Gas Code Level II12/1/2017 Typical Termination Locations for Chimneys and Single-wall Metal Pipes Serving Residential-type and Low-heat Appliances Typical Termination Locations for Chimneys and Single-wall Metal Pipes Serving Residential-type and Low-heat Appliances Copyright 2012, International Code Council

154 Section 503.5.5 Size of Chimneys2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Size of Chimneys Chimneys can be sized using one of the following methods: The provisions of Section 504. Applies only to a single appliance that is factory equipped with a draft hood. The “seven times rule” prevents the chimney from being too large, which could result in poor draft and condensation problems. Limited to only one venting arrangement, this item can only be used for a chimney that serves two appliances, both of which must be factory equipped with draft hoods. Chimneys can be sized in accordance with Section 504, by Item 2, 3 or 4 of this section or by an engineering method acceptable to the code official. Some appliances are not categorized; however, appliances with draft hoods and appliances listed for use with Type B vents would fit in Category I if they were categorized. The manufacturer’s instructions for some Category I appliances, such as fan-assisted furnaces and boilers, may not allow connecting the appliance to a masonry chimney except under specific limited conditions. 154 Copyright 2012, International Code Council

155 Section 503.5.5 Size of Chimneys2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Size of Chimneys Approved engineering methods. Other engineering methods approved by the code official. 155 Copyright 2012, International Code Council

156 Section 503.5.6 Inspection of Chimneys2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Inspection of Chimneys If a chimney is going to serve a new appliance installation or a replacement appliance installation, the chimney must be inspected to determine whether it is still serviceable and free of deposits. If previously used for venting solid or liquid fuel-burning appliance or fireplaces, the chimney must be cleaned. If a chimney is going to serve a new appliance installation or a replacement appliance installation, the chimney must be inspected to determine whether it is still serviceable and free of deposits. Chimneys can become obstructed by debris such as leaves, animal carcasses, loose mortar and pieces of masonry and liner. Combustible deposits can accumulate on chimney walls used to vent liquid- and solid-fuel-fired appliances, and this section mandates that the chimney be cleaned if it served such appliances in the past. Masonry chimneys are especially susceptible to internal deterioration and should be inspected regularly, in addition to when a new or replacement appliance is connected. 156 Copyright 2012, International Code Council

157 Section 503.5.7 Chimneys Serving Appliances Burning Other Fuels2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Chimneys Serving Appliances Burning Other Fuels This section covers: Solid fuel-burning appliances – each solid fuel-burning appliance or fireplace must be connected to a dedicated independent chimney, or a dedicated independent flue in multiple-flue chimney constructions. Liquid fuel-burning appliances – gas-fired and oil-fired appliances are allowed to share a chimney or flue. The system must be engineered or approved by the code official. Solid fuel-burning appliances - Each solid fuel-burning appliance or fireplace must be connected to a dedicated independent chimney, or a dedicated independent flue in multiple-flue chimney constructions. Solid-fuel-burning appliances and fireplaces cannot share a common chimney or flue-way with any other appliance or fireplace. Liquid fuel-burning appliances - Gas-fired and oil-fired appliances are allowed to share a chimney or flue. The code does not include a sizing method for such arrangements; therefore, the system would have to be engineered or otherwise approved by the code official. Placing the openings at different levels in the chimney flue will minimize interference between the flow of the chimney connectors. The last sentence is consistent with the design of all automatically controlled appliances listed to today’s appliance standards as required by this code. 157 Copyright 2012, International Code Council

158 Section 503.5.7 Chimneys Serving Appliances Burning Other Fuels2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Chimneys Serving Appliances Burning Other Fuels Combination gas and solid fuel-burning appliances – A dual fuel appliance, gas and solid fuel, can be served by a single chimney or flue if the appliance is equipped with a safety control that monitors chimney spillage. Combination gas- and oil-fuel-burning appliances – Can be connected to a single chimney flue if it is equipped with a manual reset device to shut off gas to the main burner in the event of sustained backdraft of flue gas spillage. Combination gas and solid fuel-burning appliances – A dual fuel appliance, gas and solid fuel, can be served by a single chimney or flue if the appliance is equipped with a safety control that monitors chimney spillage. A solid-fuel fire cannot be turned on and off like other fuel fires; thus, it is possible that the gas burner could be operated while the solid-fuel fire is still burning, and the chimney could be overloaded, causing spillage of combustion gases. The chimney size would have to be engineered or would have to comply with the appliance manufacturer’s instructions. 158 Copyright 2012, International Code Council

159 Section 503.5.8 Support of Chimneys2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Support of Chimneys Because chimneys are very heavy compared to vents, they need substantial support to carry their weight and prevent displacement. Factory-built chimneys require special support fittings at offsets to prevent the elbows from being damaged by bearing the weight of the chimney sections above the offset. Chimneys, including factory-built, are very heavy compared to vents and need substantial support to carry their weight and prevent displacement. Factory-built chimneys require special support fittings at offsets to prevent the elbows from being damaged by bearing the weight of the chimney sections above the offset. Chimneys, like piping systems, often suffer from lack of adequate support. 159 Copyright 2012, International Code Council

160 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section Cleanouts If an existing chimney has no cleanout and was used for oil or solid-fuel appliances, a cleanout must be added. The cleanout must have a tight-fitting cover and must be installed so its upper edge is at least 6 inches below the lower edge of the lowest chimney inlet opening. If an existing chimney has no cleanout and was used for oil or solid-fuel appliances, a cleanout must be added. The cleanout allows access for a person to inspect and clean the chimney and monitor deposits on the interior walls. The cleanout must be located so that vent gases will not be in contact with the cleanout door/cover. 160 Copyright 2012, International Code Council

161 Section 503.5.10 Space Surrounding Lining or Vent2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Space Surrounding Lining or Vent If a vent of a chimney liner is installed within a chimney flue, there will be space between the vent or liner and the chimney walls. This space cannot be used to convey vent gases. Also, the space between a liner, vent or pipe can the interior chimney walls cannot be used as a duct for conveying combustion air. If a vent or a chimney liner is installed within a chimney flue, there will be space between the vent or liner and the chimney walls. This space must not be used to convey vent gases because of its irregular size and geometry and because the vent gases could damage the vent or liner installed in the chimney. A metallic vent or liner could be corroded by surrounding vent gases, and plastic pipes could be overheated. Liner systems and vent systems are not listed for use within an atmosphere of vent gases. Installing multiple liners or vents within a chimney is not the same as using the annular space between a vent or liner and the inside chimney walls. 161 Copyright 2012, International Code Council

162 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section Gas Vents Gas vents must be installed following the manufacturer’s installation instructions. A Type B-W gas vent must have a listed capacity not less than that of the listed vented wall furnace to which it is connected. Gas vents installed within masonry chimneys must be installed in accordance with the manufacturer’s installation instructions. 162 Copyright 2012, International Code Council

163 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section Gas Vents Gas vents must terminate according to Section , which duplicates type vent manufacturers’ instructions and emphasizes that a vent is a system of components that are all necessary for proper functioning. 163 Copyright 2012, International Code Council

164 Section 503.7 Single-wall Metal Pipe2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Single-wall Metal Pipe This section addresses single-wall pipe used as a vent, not single-wall pipe used as a vent connector. Use of single-wall metal pipe is restricted to very limited applications, and extraordinary installations precautions are necessary. This section addresses single-wall pipe used as a vent, not single-wall pipe used as a vent connector. Although discouraged or prohibited by designers, code officials and appliance and vent manufacturers alike, the code still recognizes the use of unlisted single-wall metal pipe as a vent. All other types of vents are listed systems as required by Section As evidenced by Sections through , single-wall metal pipe is restricted to very limited applications, and extraordinary installation precautions are necessary. Single-wall metal pipe was once common, but, it will not be found today except in extremely rare circumstances and in older existing buildings. Appliance manufacturers’ instructions will typically prohibit the use of a single-wall metal vent. 164 Copyright 2012, International Code Council

165 Section 503.8 Venting System Termination Location2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Venting System Termination Location This section addresses the terminations of mechanical draft systems and direct-vent appliances. The location of venting system terminations must comply with the following: Forced air intakes of a mechanical draft venting system must be at least 10 feet away from a mechanical draft termination, or the termination must be at least 3 feet above the air intake. 165 Copyright 2012, International Code Council

166 Section 503.8 Venting System Termination Location2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Venting System Termination Location A mechanical draft venting system must terminate at least 4 feet below, 4 feet horizontally from, or 1 foot above any door, operable window or gravity air inlet into any building. The bottom of the vent terminal must be located at least 12 inches above finished ground level. 166 Copyright 2012, International Code Council

167 Section 503.8 Venting System Termination Location2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Venting System Termination Location Provides specific distances to allow combustion gases to dissipate in the atmosphere, thus avoiding entry into the building through openings. This item is applicable only to direct-vent appliances. Through-the-wall vents (for Category II and IV appliances) must not terminate over public walkways or over an area where condensate or vapor could cause a nuisance or hazard, or could interfere with the proper operation of regulators, relief valves, or other equipment. 167 Copyright 2012, International Code Council

168 Mechanical Draft Venting System Exhauster Terminations2012 North Carolina Fuel Gas Code Level II 12/1/2017 Mechanical Draft Venting System Exhauster Terminations 168 Copyright 2012, International Code Council

169 Section 503.9 Condensation Drainage2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Condensation Drainage In accordance with Section 503.8, provisions must be made to collect and dispose of condensate from venting systems serving Category II and IV appliances. Where local experience indicates that condensation is a problem, provisions must be made to drain off and dispose of condensate from venting systems serving Category I and III appliances, as well. 169 Copyright 2012, International Code Council

170 Section 503.10 Vent Connectors for Category I Appliances2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Vent Connectors for Category I Appliances A vent connector is necessary to connect an appliance’s flue outlet to the vent or chimney. Vent and chimney connectors can be single- or double-wall pipes and are usually made from steel, galvanized steel, stainless steel or aluminum sheet metal, depending on the application. Section regulates the location, length, size and type of connectors. Unless the chimney or vent is connected directly to the appliance, a connector, defined in Section 202 as pipe used to connect an approved fuel-burning appliance to a chimney or vent, is necessary. This includes the fittings necessary to make a connection or change in direction. This is usually accomplished with a single-wall metal pipe, but it is also common practice to use listed and labeled chimney and vent pipe or listed factory-built single-wall or double-wall bendable connectors. 170 Copyright 2012, International Code Council

172 Section 503.11 Vent Connectors for Category II, III and IV Appliances2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Vent Connectors for Category II, III and IV Appliances Vent connectors for Category II, III and IV appliances are specified for the venting systems in accordance with Section 172 Copyright 2012, International Code Council

173 Section 503.12 Draft Hoods and Draft Controls2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Draft Hoods and Draft Controls Draft hoods are integral to or supplied with natural draft atmospheric-burner gas-fired appliances other than fan-assisted appliances. They are classified by the manufacturer as Category I appliances. Draft-hood-equipped appliances are becoming increasingly rare in the marketplace though they are still common on conventional tank-type and tankless water heaters and 80 percent efficient boilers. 173 Copyright 2012, International Code Council

174 Section 503.12 Draft Hoods and Draft Controls2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Draft Hoods and Draft Controls This section regulates the installation, location, clearance and draft control devices associated with draft-hood- equipped appliances. 174 Copyright 2012, International Code Council

175 Section 503.13 Manually Operated Dampers2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Manually Operated Dampers Because manual dampers rely on operation by a human and humans forget, they cannot be placed in the vent connector for any appliance. Fixed baffles cannot be classified as manually operated dampers. Manual dampers are associated with solid-fuel appliances but not with gas-fired appliances. A manual damper requires manual operation by a human, which cannot be relied on because humans forget. If a damper is left closed or partially closed during appliance operation, a severe hazard could result from vent-gas spillage and/or appliance malfunction. 175 Copyright 2012, International Code Council

176 Section 503.14 Automatically Operated Vent Dampers2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Automatically Operated Vent Dampers Automatic vent dampers are safer than manually operated dampers. They must be installed following the manufacturer’s installation instructions, and must be listed and labeled. Automatic vent dampers are intended for use with gas-fired natural-draft appliances. An automatic vent damper must be installed in strict compliance with the manufacturer’s installation instructions. Because automatic vent-damper failure can result in a hazardous condition, automatic dampers must be listed and labeled. An automatic vent damper is installed on the draft hood outlet of an individual gas-fired appliance. These dampers must not serve more than one appliance. The manufacturer’s installation instructions require that the damper be installed by a qualified installer in accordance with the terms of the listing and the manufacturer’s instructions. 176 Copyright 2012, International Code Council

177 Section 503.16 Outside Wall Penetrations2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section Outside Wall Penetrations Where vents penetrate outside walls of buildings, the annular spaces around the penetrations must be permanently sealed using approved materials to prevent entry of combustion products into building. Vents that terminate through outside walls are subject to being covered (buried) in snow in many climates and experience has shown that combustion products can enter the building through the annular space between the vent and the wall assembly. In some cases, snow cover can trap combustion gases and cause them to reenter a direct-vent appliance combustion chamber via the combustion air intake. This will generate excessive carbon monoxide levels as a result of oxygen depletion. The snow cover can trap and channel these toxic gasses into the building through any unsealed annular space in the wall penetration. The required sealing must be permanent and able to tolerate movement of the vent caused by expansion and contraction of the vent. Plastic pipe used for vents will expand and contract much more than metal pipe, and the annular space seal will be broken if allowances are not made for this movement. 177 Copyright 2012, International Code Council

178 Section 504 Sizing of Category I Appliance Venting Systems2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 504 Sizing of Category I Appliance Venting Systems The following definitions are necessary for application of the vent sizing tables in this section: Appliance Categorized Vent Diameter/Area Fan-assisted Combustion System FAN Min. FAN Max. 178 Copyright 2012, International Code Council

179 Section 504 Sizing of Category I Appliance Venting Systems2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 504 Sizing of Category I Appliance Venting Systems The following definitions are necessary for application of the vent sizing tables in this section (cont.): NAT Max. FAN + FAN. FAN + NAT. NA. NAT + NAT. 179 Copyright 2012, International Code Council

180 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section Definitions Appliance Categorized Vent Diameter/Area – The minimum vent area/diameter permissible for Category I appliances to maintain a non-positive vent static pressure when tested in accordance with nationally recognized standards. The minimum Category I appliance vent area/diameter necessary to maintain a nonpositive vent static pressure when tested in accordance with the applicable standard. The appliance categorized vent diameter/area is determined by the appliance manufacturer and is typically the vent outlet collar installed on the appliance. 180 Copyright 2012, International Code Council

181 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section Definitions Fan-assisted Combustion System – An appliance equipped with an integral mechanical means to either draw or force products of combustion through the combustion chamber or heat exchanger. An appliance equipped with an integral mechanical means to either draw or force products of combustion through the combustion chamber or heat exchanger. 181 Copyright 2012, International Code Council

182 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section Definitions FAN Min – The minimum input rating of a Category I fan-assisted appliance attached to a vent or connector. FAN Max – The maximum input rating of a Category I fan-assisted appliance attached to a vent or connector. NAT Max – The maximum input rating of a Category I draft-hood-equipped appliance attached to a vent or connector. FAN + FAN – The maximum combined appliance input rating of two or more Category I fan-assisted appliances attached to the common vent. FAN Min - The minimum appliance input rating of a Category I appliance with a fan-assisted combustion system that is capable of being attached to a vent. FAN Max - The maximum appliance input rating of a Category I appliance with a fan-assisted combustion system that is capable of being attached to a vent. NAT Max - The maximum appliance input rating of a Category I appliance with a fan-assisted combustion system that is capable of being attached to a vent. 182 Copyright 2012, International Code Council

183 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section Definitions FAN + NAT – The maximum combined appliance input rating of one or more Category I fan-assisted appliances and one or more Category I draft-hood-equipped appliances attached to a vent or connector. NA – Vent configuration is not allowed due to potential for condensate formation or pressurization of the venting system, or not applicable due to physical or geometric restraints. NAT + NAT – The maximum combined appliance input rating of two or more Category I draft-hood-equipped appliances attached to a vent or connector. 183 Copyright 2012, International Code Council

184 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section Application of Single-appliance Vent Tables 504.2(1) through 504.2(6) The application of Tables 504.2(1) through 504.2(6) are subject to the following requirements: Vent obstructions. Minimum size. Vent offsets. Zero lateral. High-altitude installations. Multiple input rate appliances. 184 Copyright 2012, International Code Council

185 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section Application of Single-appliance Vent Tables 504.2(1) through 504.2(6) Liner system sizing and connections. Vent area and diameter. Chimney and vent locations. Corrugated vent connector size. Vent connector size limitation. Component commingling. Draft hood conversion accessories. Table interpolation Extrapolation prohibited Engineering calculations. 185 Copyright 2012, International Code Council

186 Example: Table Interpolation2012 North Carolina Fuel Gas Code Level II 12/1/2017 Example: Table Interpolation 2009 IFGC Commentary—Examples 1 and 2, page 5-75 186 Copyright 2012, International Code Council

187 Activity: Application of the Single Appliance Tables2012 North Carolina Fuel Gas Code Level II 12/1/2017 Activity: Application of the Single Appliance Tables PLACEHOLDER 187 Copyright 2012, International Code Council

188 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section Application of Multiple Appliance Vent Tables 504.3(1) through 504.3(7) The application of Tables 504.3(1) through 504.3(7) are subject to the following requirements: Vent obstructions. Connector length limit. Connectors with longer lengths. Vent connector manifold. Common vertical vent offset. Elbows in vents. Elbows in connectors. The application of Tables 504.3(1) through 504.3(4) shall be subject to the requirements of Sections through This part of Section 504 regulates vents and chimneys that serve more than one appliance. These venting systems can be described as combined vents and include multiple connectors. A “combined vent” is a vent for two or more appliances at one level served by a common vent. “Least total height” is the vertical distance from the highest appliance outlet (draft hood or flue collar) to the lowest discharge opening of the vent top. 188 Copyright 2012, International Code Council

189 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section Application of Multiple Appliance Vent Tables 504.3(1) through 504.3(7) Common vent minimum size. High-altitude installations. Connector rise measurement. Vent height measurement. Multistory height measurement. Multistory lowest portion sizing. Multistory common vents. Multistory common vent offsets. Vertical vent maximum size. Multiple input rate appliances. 189 Copyright 2012, International Code Council

190 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section Application of Multiple Appliance Vent Tables 504.3(1) through 504.3(7) Liner system sizing and connections. Chimney and vent location. Connector maximum and minimum size. Component commingling. Draft hood conversion accessories. Multiple sizes permitted. Table interpolation. Extrapolation prohibited. Engineering calculations. 190 Copyright 2012, International Code Council

191 Activity: Application of the Common Venting Tables2012 North Carolina Fuel Gas Code Level II 12/1/2017 Activity: Application of the Common Venting Tables PLACEHOLDER 191 Copyright 2012, International Code Council

194 Section 506 Factory-built Chimneys2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 506 Factory-built Chimneys Factory-built chimneys can be used with gas-fired appliances if allowed by the chimney manufacturer. The sizing tables in Section 504 do not apply to factory-built chimneys, so sizing must be engineered or as specified by the chimney and appliance manufacturers’ instructions. Factory-built chimneys can be used with gas-fired appliances if allowed by the chimney manufacturer. The sizing tables in Section 504 do not apply to factory-built chimneys; therefore, sizing must be engineered or as specified by the chimney and appliance manufacturers’ instructions. Factory-built chimneys will be too large for many residential gas appliances. 194 Copyright 2012, International Code Council

195 Activity: Single Fan-assisted Appliance2012 North Carolina Fuel Gas Code Level II 12/1/2017 Activity: Single Fan-assisted Appliance An installer has an 80,000 Btu per hour input fan-assisted appliance that must be installed using 10 feet of lateral connector attached to a 30-foot-high Type B vent. Two 90-degree elbows are needed for the installation. Can a single-wall metal vent connector be used for this application? 195 Copyright 2012, International Code Council

197 Activity: Interpolating Between Table Values2012 North Carolina Fuel Gas Code Level II 12/1/2017 Activity: Interpolating Between Table Values An installer has an 80,000 Btu per hour input appliance with a 4-inch diameter draft hood outlet that needs to be vented into a 12-foot-high Type B vent. The vent connector has a 5-foot lateral length and is also Type B. Can this appliance e vented using a 4-inch-diameter vent? 197 Copyright 2012, International Code Council

198 Activity: Common Venting Two Draft-hood-equipped Appliances2012 North Carolina Fuel Gas Code Level II 12/1/2017 Activity: Common Venting Two Draft-hood-equipped Appliances A 35,000 Btu per hour water heater is to be common vented with a 150,000 Btu per hour furnace using a common vent with a total height of 30 feet. The connector rise is 2 feet for the water heater with a horizontal length of 4 feet. The connector rise for the furnace is 3 feet with a horizontal length of 8 feet. Assume single-wall metal connectors will be used with Type B vent. What size connectors and combined vent should be used in this installation? 198 Copyright 2012, International Code Council

201 Chapter 6: Specific Appliances2012 North Carolina Fuel Gas Code Level II 12/1/2017 Chapter 6: Specific Appliances Chapter 6 regulates the design, installation and location of specifically named gas-fired appliances, such as furnaces, boilers, water heaters, heaters, cooking and lighting appliances and clothes dryers. It stipulates that the specific appliances must be listed and labeled and installed in accordance with the manufacturer’s instructions. This chapter contains requirements for specific appliances and their installation. In addition to being listed and labeled, many appliances have special installation or location requirements. Unlike Chapter 3, titled General Regulations, this chapter contains and organizes the specific regulations applicable to certain appliances. 201 Copyright 2012, International Code Council

202 Specific Appliances Covered2012 North Carolina Fuel Gas Code Level II 12/1/2017 Specific Appliances Covered Decorative Appliances for Installation in Fireplaces (Section 602) Vented Gas Fireplaces (Section 604) Vented Gas Fireplace Heaters (Section 605) Vented Wall Furnaces (Section 608) Floor Furnaces (Section 609) Forced-air Warm-air Furnaces (Section 618) Unvented Room Heaters (Section 621) Cooking Appliances (Section 623) 202 Copyright 2012, International Code Council

203 Section 602 Decorative Appliances for Installation in Fireplaces2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 602 Decorative Appliances for Installation in Fireplaces Include gas log sets that are designed to simulate wood fires. The applicable test standard is ANSI Z21.60 or Z21.84. The label indicates that an independent agency has conducted inspections at the plant to verify that all units conform to the specifications that the quality control manual sets for fabricating the gas appliances. These appliances include gas log sets that are designed to simulate wood fires. Sections 301 through 310 address the requirements for testing, labeling and installing mechanical equipment and appliances. The gas-burning appliance must be tested to the standard or standards appropriate for the equipment. The testing agency is responsible for determining the standard to be used to test the equipment. In the case of decorative gas log sets, ANSI Z21.60 or Z21.84 is the applicable test standard. 203 Copyright 2012, International Code Council

204 Section 604 Vented Gas Fireplaces2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 604 Vented Gas Fireplaces These appliances are self-contained and do not rely on a fireplace to contain or vent them. They are referred to as “gas fireplaces” and are subject to ANSI Z21.50. They are vented directly through the wall or roof and conventionally with Type B vent or factory-supplied vent material. Unlike the appliances addressed in Section 602, these appliances are self-contained and do not rely on a fireplace to contain or vent them. Such appliances are referred to as gas fireplaces because they are designed to simulate a solid-fuel-burning fireplace. The standard, ANSI Z21.50, that regulates these appliances has recently been retitled as “Vented Gas Fireplaces.” Therefore, these appliances will be referred to as gas fireplaces even though they do not fall under the definition of “fireplace”. These appliances are designed for various methods of venting, including direct-venting through the wall or roof and conventional venting with Type B vent or factory-supplied vent material. Section controls the type of appliance that is allowed in bathrooms, toilet rooms and bedrooms. Direct-vent appliances have the advantage of a closed combustion chamber that does not communicate with the room in which they are installed, as well as the advantage of an outdoor combustion air supply 204 Copyright 2012, International Code Council

206 Section 605 Vented Gas Fireplace Heaters2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 605 Vented Gas Fireplace Heaters These appliances are designed with more emphasis on space heating while maintaining the decorative features. They must comply with minimum thermal efficiency requirements. 206 Copyright 2012, International Code Council

207 Section 608 Vented Wall Furnaces2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 608 Vented Wall Furnaces These appliances are a type of room heater usually designed to be installed within a 2- by 4-inch stud cavity in frame construction. They are typically used in cottages, room additions and homes in mild climates. They must be tested in accordance with ANSI Z21.86/CSA 2.32. Wall furnaces are a type of room heater usually designed to be installed within a 2- by 4-inch stud cavity in frame construction. They are typically used in cottages, room additions and homes in mild climates. Some units are designed to serve a single room, and others are designed as through-the-wall units to serve adjacent rooms. Wall furnaces are ductless; however, some units are listed for use with a surface-mounted supply outlet extension. Wall furnaces can be either gravity or forced air type. Copyright 2012, International Code Council

208 Section 609 Floor Furnaces2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 609 Floor Furnaces Floor furnaces are vented appliances that are installed in an opening in the floor. They heat the room by gravity convection and direct radiation. They can pose as a fire hazard if care is not taken to keep them clear of materials or furnishings. Floor furnaces are vented appliances that are installed in an opening in the floor. These units heat the room by gravity convection and direct radiation and usually serve as the sole source of space heating. Such furnaces are common in cottages, small homes, seasonally occupied structures and rural homes. Because the floor grille can become hot, extreme care must be exercised to prevent occupants, especially children, from contacting the grille by walking or falling on it. Also, care must be taken to avoid a fire hazard caused by placement of materials or furnishings on or near the furnace floor grille. 208 Copyright 2012, International Code Council

209 Section 611 Nonrecirculating Direct-fired Industrial Air Heaters2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 611 Nonrecirculating Direct-fired Industrial Air Heaters Direct-fired air-heating equipment is unique in that there is no heat exchanger to separate the burners from the air being heated. The heat of combustion and all byproducts are directly introduced into the airstream. The air that passes across the burner must be 100 percent outdoor air. Direct-fired air-heating equipment is unique in that there is no heat exchanger to separate the burners from the air being heated. As the name implies, the heat of combustion and all byproducts are directly introduced into the airstream. Because there is no heat exchanger, chimney or vent, direct-fired heaters are close to 100-percent energy efficient. The term “nonrecirculating” refers to the fact that the same air is not passed through the combustion zone more than once. In other words, these units heat 100 percent outdoor air and are what used to be referred to as make-up air heaters. The air that passes across the burner must be 100 percent outdoor air. 209 Copyright 2012, International Code Council

210 Section 612 Recirculating Direct-fired Industrial Air Heaters2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 612 Recirculating Direct-fired Industrial Air Heaters Recirculating direct-fired industrial air heaters are usually used to condition very large volume buildings used as factories, mills, and warehouses. They most often consist of ductless blower and burner assemblies that turn over the air in the building through a vertical air discharge configuration. 210 Copyright 2012, International Code Council

211 2012 North Carolina Fuel Gas Code Level II12/1/2017 Basic Principle of Direct-fired Space Heating Appliance Basic Principle of Indirect-fired Space Heating Appliance Copyright 2012, International Code Council

212 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section 615 Sauna Heaters Sauna heaters are used in steam baths and similar rooms to generate heat and steam. They must be installed in compliance with the manufacturer’s instructions to ensure they are installed as designed and tested. The code relies on these installation instructions rather than stating prescriptive requirements that might contradict the manufacturer. 212 Copyright 2012, International Code Council

213 Section 617 Pool and Spa Heaters2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 617 Pool and Spa Heaters Pool and spa heaters are specialized water heaters very similar in design to hot water supply boilers and are used with swimming pools, recreational or therapeutic spas and hot tubs. These heaters are usually of the water-tube type and are designed for either indoor or outdoor installation. 213 Copyright 2012, International Code Council

214 Section 618 Forced-air Warm-air Furnaces2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 618 Forced-air Warm-air Furnaces These are considered to be central heating units and consist of burners or heating elements, heat exchangers, blowers and associated controls. They must be tested in accordance with ANSI Z21.47 or UL 795. 214 Copyright 2012, International Code Council

215 2012 North Carolina Fuel Gas Code Level II12/1/2017 Section 620 Unit Heaters Unit heaters are ductless warm-air space heaters that are self-contained and usually suspended from a ceiling or roof structure. Garages, workshops, warehouses, factories, gymnasiums, mercantile spaces and similar large, open spaces are the most common locations for unit heaters. 215 Copyright 2012, International Code Council

216 Section 621 Unvented Room Heaters2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 621 Unvented Room Heaters These heaters are limited-size gas-fired space heaters that discharge the combustion byproducts into the space being heated. They must be listed and labeled and installed following the manufacturer’s installation instructions. They must be tested in accordance with ANSI Z 216 Copyright 2012, International Code Council

218 Section 623 Cooking Appliances2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 623 Cooking Appliances This section addresses cooking appliances in all occupancies that are designed for permanent installation, including, but not limited to: Ranges. Ovens. Stoves. Broilers. Grills. Fryers. Griddles. Barbecues. These appliances must be installed in accordance with the listing and the manufacturer’s installation instructions . The code intends to regulate the design, construction and installation of cooking appliances that are designed for permanent installation-heated counter-top appliances. Appliances that are not readily moveable to another location because of a gas-fuel supply connection would be considered permanently installed, even if they were on casters. Line equipment under a Type I hood, for example, is usually on casters and connected with quick-disconnect-type fuel supply lines to allow movement for routine cleaning. This kind of equipment would be considered permanently installed. 218 Copyright 2012, International Code Council

221 Chapter 7: Gaseous Hydrogen Systems2012 North Carolina Fuel Gas Code Level II 12/1/2017 Chapter 7: Gaseous Hydrogen Systems Provides for the installation of hydrogen systems to reduce the hazards that are associated with flammable gases and those that are unique to hydrogen. The use of hydrogen as a fuel for power generation and vehicles is expected to grow in the near future as the technology continues to advance and a hydrogen infrastructure is built. Hydrogen is a colorless, odorless, tasteless, flammable nontoxic gas that burns with an almost invisible bluish flame. A hydrogen flame is very pale and difficult to see in daylight. A major concern with hydrogen is the fact that odorants cannot be added because the chemicals involved would poison the fuel cells, thus hydrogen is not odorized and cannot be detected by any of the human senses. 221 Copyright 2012, International Code Council

222 Chapter 7: Gaseous Hydrogen Systems2012 North Carolina Fuel Gas Code Level II 12/1/2017 Chapter 7: Gaseous Hydrogen Systems The use of hydrogen systems is very new—when encountered, the code official should contact an hydrogen-system expert. 222 Copyright 2012, International Code Council

224 Section 702 General Definitions2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 702 General Definitions Gaseous Hydrogen System – An assembly of piping, devices and apparatus designed to generate, store, contain, distribute or transport a nontoxic, gaseous hydrogen containing mixture having at least 95-percent hydrogen gas by volume and not more than 1-percent oxygen by volume. This term includes the source of hydrogen and all piping and devices between the source and the using equipment. The gas in a hydrogen system is above the upper flammability limit and is therefore, “too rich” to burn. Any leakage, however, will quickly form an explosive mixture in the ambient atmosphere. 224 Copyright 2012, International Code Council

225 Section 702 General Definitions2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 702 General Definitions Gaseous Hydrogen System (cont.) – Gaseous hydrogen systems consist of items such as compressed gas containers, reactors and appurtenances, including pressure regulators, pressure relief devices, manifolds, pumps, compressors and interconnecting piping and tubing and controls. 225 Copyright 2012, International Code Council

226 Section 702 General Definitions2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 702 General Definitions Hydrogen Cutoff Room – A room or space which is intended exclusively to house a gaseous hydrogen system. Hydrogen-generating Appliance – A self-contained package or factory-matched packages of integrated systems for generating gaseous hydrogen. Hydrogen-generating appliances utilize electrolysis, reformation, chemical or other processes to generate hydrogen. Hydrogen cutoff room - An enclosed space used exclusively for a gaseous hydrogen system requires construction and protection that are unique to the hazards associated with these areas. The definition itself should not be interpreted to preclude H2 piping systems from serving distributed hydrogen-using equipment and appliances located elsewhere on site or in the building. However, the appropriate material-specific quantity limitations of the International Building Code and the IFC must be consulted. Hydrogen-generating appliance - Hydrogen generators use water or hydrocarbon fuels as a feedstock for generation of pure hydrogen or a hydrogen-rich gas. Hydrogen-generating appliances based on chemical reformers separate out the hydrogen from fossil fuels such as natural gas, propane, gasoline, etc. This is the same high-temperature chemical process used at large oil refineries to produce hydrogen. By generating the hydrogen onsite at the fueling station or customer’s facility, these hydrogen-generating appliances avoid the high cost of either liquefying hydrogen and delivering it by cryogenic tanker truck, or installing a national hydrogen pipeline system that could cost many tens of billions of dollars. In effect, these on-site hydrogen-generating appliances take advantage of one of two existing energy infrastructures: either the natural gas distribution system or the electrical grid. 226 Copyright 2012, International Code Council

228 Section 703 General Requirements2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 703 General Requirements This section intends to minimize the potential for explosions by limiting the source of hydrogen gas and by requiring sufficient ventilation to dissipate any leakage. 228 Copyright 2012, International Code Council

229 Section 704 Piping, Use and Handling2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 704 Piping, Use and Handling All hydrogen system components must be listed for the application unless specifically approved by the code official. All components must be carefully chosen as suitable for the application, especially because of the extreme flammability, small molecule size, lack of detectable odor and high pressure associated with hydrogen. 229 Copyright 2012, International Code Council

230 Section 705 Testing of Hydrogen Piping Systems2012 North Carolina Fuel Gas Code Level II 12/1/2017 Section 705 Testing of Hydrogen Piping Systems After installation, field-erecting piping, tubing, hose and hose assemblies must be tested and proved hydrogen gas-tight for the rated pressure and temperature of the gas conveyed in that portion of the system. Inspection of piping installations is intended to be a visual observation of the system and the testing procedure. 230 Copyright 2012, International Code Council

232 Chapter 8: Referenced Standards2012 North Carolina Fuel Gas Code Level II 12/1/2017 Chapter 8: Referenced Standards Chapter 8 contains a comprehensive list of standards that are referenced in the code. It is organized to make locating specific document references easy. 232 Copyright 2012, International Code Council

2012 North Carolina Fuel Gas Code Level II Level II Training

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