NFPA 37 Public Comment Responses Page 1 of 32

of 30 11/4/2016 3:05 PM Public Comment No. 6-NFPA 37-2016 [ New Section after 1.6 ] TITLE OF NEW CONTENT Type your content here... 1.7 Pressure Measurement. All pressures expressed in this document are gauge pressures unless specifically noted otherwise. change is being made to coordinate with the proposed revisions to section 5.6. First Revision No. 11-NFPA 37-2015 [New Section after 5.5] Submitter Full Name: Kevin Carlisle Organization: Karl Dungs, Inc. Submittal Date: Fri May 06 15:30:13 EDT 2016 Committee Rejected but see related SR Action: Resolution: SR-13-NFPA 37-2016 Statement: This revision is made to coordinate with the revisions to section 5.6 (see SR-14) and to clarify the units of pressure measurement. NFPA 37 Public Comment Responses Page 1 of 32

of 30 11/4/2016 3:05 PM Public Comment No. 10-NFPA 37-2016 [ New Section after 3.3.7 ] TITLE OF NEW CONTENT Inlet Gas Pressure: The pressure at the outlet of the equipment isolation valve. change is being made to coordinate with the proposed revisions to section 5.6 First Revision No. 22-NFPA 37-2015 [Global Input] Submitter Full Name: Kevin Carlisle Organization: Karl Dungs, Inc. Submittal Date: Fri May 06 15:37:38 EDT 2016 Committee Action: Rejected but see related SR Resolution: SR-2-NFPA 37-2016 Statement: This definition is added to explain terminology used in section 5.6 (see SR-14). NFPA 37 Public Comment Responses Page 2 of 32

of 30 11/4/2016 3:05 PM Public Comment No. 8-NFPA 37-2016 [ New Section after 3.3.7 ] TITLE OF NEW CONTENT Line Pressure Regulator: A pressure regulator placed in a gas line between the service regulator and the appliance regulator [ 54, 2015] change is being made to coordinate with the proposed revisions to section 5.6 First Revision No. 22-NFPA 37-2015 [Global Input] Submitter Full Name: Kevin Carlisle Organization: Karl Dungs, Inc. Submittal Date: Fri May 06 15:33:20 EDT 2016 Committee Action: Rejected but see related SR Resolution: SR-3-NFPA 37-2016 Statement: This definition is added to explain terminology used in section 5.6 (see SR-14). NFPA 37 Public Comment Responses Page 3 of 32

of 30 11/4/2016 3:05 PM Public Comment No. 9-NFPA 37-2016 [ New Section after 3.3.9 ] Rated Pressure. The maximum internal and external pressures that the materials, devices, or components are designed to contain or control. change is being made to coordinate with the proposed revisions to section 5.6 First Revision No. 22-NFPA 37-2015 [Global Input] Submitter Full Name: Kevin Carlisle Organization: Karl Dungs, Inc. Submittal Date: Fri May 06 15:36:08 EDT 2016 Committee Action: Accepted Resolution: SR-4-NFPA 37-2016 Statement: This definition is added to explain terminology used in section 5.6 (see SR-14). NFPA 37 Public Comment Responses Page 4 of 32

of 30 11/4/2016 3:05 PM Public Comment No. 7-NFPA 37-2016 [ Section No. 3.3.9 ] 3.3.9 Protected Pressure. The set pressure of the nearest upstream overpressure protection device or the inlet pressure to the service regulator, whichever is lower. change is being made to coordinate with the proposed revisions to section 5.6 First Revision No. 22-NFPA 37-2015 [Global Input] Submitter Full Name: Kevin Carlisle Organization: Karl Dungs, Inc. Submittal Date: Fri May 06 15:32:33 EDT 2016 Committee Accepted Action: Resolution: SR-5-NFPA 37-2016 Statement: This revision is made to coordinate with the revisions to section 5.6 (see SR-14). The term "protected pressure" is no longer used in the document. NFPA 37 Public Comment Responses Page 5 of 32

of 30 11/4/2016 3:05 PM Public Comment No. 1-NFPA 37-2016 [ Section No. 4.1.3 ] 4.1.3 Engines Located on Roofs, Platforms, and Other Supporting Structures. 4.1.3.1 Engines, and their weatherproof housings, if provided, that are installed on roofs of structures, on platforms, or on other supporting structures shall be located at least 1.5 m (5 ft) from openings in walls and at least 1.5 m (5 ft) from structures having combustible walls. A minimum separation shall not be required where the following conditions exist: The adjacent wall of the structure has combustible structures except as provided in 4.1.3.1.1 or 4.1.3.1.2 4.1.3.1.1 A clearance less than 1.5 m (5 ft) shall be permitted where all portions of the structure that are closer than 1.5 m (5 ft) from the engine enclosure have a fire resistance rating of at least 1 hour. * The weatherproof enclosure is constructed of noncombustible materials and it has been demonstrated hr. 4.1.3.1.2 A clearance less than 1.5m (5 ft) shall be permitted where it has been demonstrated through testing by a Nationally Recognized Testing Laboratory acceptable to the authority having jurisdiction that a fire within the enclosure will not ignite combustible materials outside the enclosure structures. 4.1.3.2 An oil A liquid containment system consisting of a curb or dike having a capacity at least equal to the total capacity of the lubricating oil system or, the liquid fuel system, whichever is greater and the engine coolant system, shall be provided. This system shall also comply with applicable requirements of Chapter 6 except as provided in 4.1.3.2.1. 4.1.3. 3 * 2.1 Where engines are connected to a Chapter 5 fuel supply system, a liquid containment system shall not be required where engines provided with weatherproof housings have the available capacity to contain the total capacity of the oil lubricating system and engine coolant system within the weatherproof enclosure. NFPA 37 Public Comment Responses Page 6 of 32

of 30 11/4/2016 3:05 PM 4.1.3.3 The surface beneath the engine and beyond the engine and the oil liquid containment dike shall be noncombustible to a minimum distance of 300 mm (12 in.), except as provided in 4.1.3.3.1. 4.1.3.3.1 The surface beneath the engine and beyond the engine and the liquid containment dike, if provided, shall not be required to be noncombustible where it has be demonstrated through testing by a Nationally Recognized Testing Laboratory acceptable to the authority having jurisdiction that a fire within the enclosure will not ignite the roofs of structures, platforms constructed of combustible materials, or other supporting structures. Additional Proposed Changes File Name 20_kw_residential_generac_on_a_raised_platform_serviced_by_NNG_automatic_standby_generators- 540x272.jpg Generac_air-cooled.gif kohler-generator-on-a-platform-installed-by-nng-in_richmond_county.jpg Kolher_.jpg 27_kw_kilowatt_generac_generator_on_a_custom_built_platform_by_northern_neck_generator_in_middlesex.jpg generac-48kw-generator-on-raised-platform-and-200-amp-transfer-switch-installed-by-northern-neck-generatorin-kilmarnock.jpg generac-70-kilowatt-generator-installed-on-a-raised-platform-by-nng-standby-generators.jpg NFPA 37 Public Comment Responses Page 7 of 32

of 30 11/4/2016 3:05 PM Bad_Core_Power.JPG The placement changes made in FR 1 to 4.1.4 would also apply to 4.1.3 as an engine located on top of a structure (roof) is also an engine located outdoors. The language should be identical for enforcement purposes. With the expansion of the installation of permanently installed residential generators throughout the country, there have been concerns with the placement of these units on combustible supporting structures. NFPA 37, 4.1.3 covered the placement of large scale commercial and industrial generator on roofs, but did not address requirements for residential applications. Areas of the country that are in FEMA flood zones require equipment to be installed above the flood level. A common practice to raise the generator above these FEMA flood levels, has been the placement of the generator on a platform constructed of combustible materials, or on an existing wood deck, porch or other structure suitable for supporting the generator. These small residential generators are then connected to a fixed fuel piping system, either natural gas or LP vapor. The generators installed on platforms in the attached pictures do not have a noncombustible separation installed between the generator and the supporting structure. If the generator were to have a fire within the enclosure, the fire could spread to the combustible platform and the platform could collapse. When this occurs the generator connection to the fixed fuel piping system can be compromised, and now a fuel gas is discharging into atmosphere next to an open flame. The public comment would add clarity to the code that any combustible structure that is utilized to support any generator would be required to be fully protected from a fire within the generator enclosure. The change to liquid containment dike would add clarity that the engine coolant is as important to contain as the engine oil and fuel, and if all systems are compromised the total capacity of all systems shall be contained. Although the concept of a water-based fluid being flammable may be difficult for installers to comprehend, one must recognize that coolant is actually glycol based and only mixed with water. Raised to a high enough temperature, the glycol is still flammable even in the presence of water vapor. The exception to the requirement for the containment dike would allow the weatherproof enclosure of small air-cooled and liquid-cooled generators that are connected to a Chapter 5 fuel supply system to serve this purpose as long as the enclosure has the available capacity. Small air-generator cooled engine generators contain on average 2 quarts of oil or less. SwRI, and OSHA NRTL, has performed enclosure testing on engine enclosures for generator manufacturers. These tests were performed for generators installed at grade level, however if additional testing can demonstrate that the engine enclosure will not ignite a combustible supporting structure, consideration should be given to the listed engine enclosure serving as the required noncombustible separation and additional noncombustible separations should not be required. Related Public Comments for This Document Related Comment Relationship Public Comment No. 2-NFPA 37-2016 [Section No. 4.1.4] Public Input No. 1-NFPA 37-2014 [Section No. 5.4.3 [Excluding any Sub-Sections]] NFPA 37 Public Comment Responses Page 8 of 32

of 30 11/4/2016 3:05 PM Submitter Full Name: Brian Baughman Organization: Generac Power Systems Submittal Date: Wed Mar 02 16:57:11 EST 2016 Committee Rejected but see related SR Action: Resolution: SR-15-NFPA 37-2016 Statement: These revisions clarify the requirements for the reader. Annex material was also added to clarify that it might be possible for the weatherproof housing to act as the oil containment system. With respect to the proposed changes in PC-1, the committee agrees that platforms and other structures are better addressed in section 4.2 (See SR-10). The flammability of engine coolant is considered negligible, and although it may need to be addressed from an environmental standpoint, it does not need to be addressed from a fire standpoint. NFPA 37 Public Comment Responses Page 9 of 32

0 of 30 11/4/2016 3:05 PM Public Comment No. 2-NFPA 37-2016 [ Section No. 4.1.4 ] 4.1.4 Engines Located Outdoors. 4.1.4.1 Engines, and their weatherproof housings, if provided, that are installed outdoors shall be located at least 1.5 m (5 ft) from openings in walls and at least 1.5 m (5 ft) from combustible structures except as provided in 4.1.4.1.1 or 4.1.4.1.2 4.1.4.1.1 A clearance less than 1.5 m (5 ft) shall be permitted where all portions of structures that are closer than 1.5 m (5 ft) from the engine enclosure have a fire resistance rating of at least 1 hour. 4.1.4.1.2 A clearance less than 1.5 m (5 ft) shall be permitted where it has been demonstrated by one of the following methods through testing by a Nationally Recognized Testing Laboratory acceptable to the authority having jurisdiction that a fire within the enclosure will not ignite structures: * Where a full-scale fire test has shown that the complete consumption of the combustibles within the enclosure will not ignite structures, the engine structure. Engines, and their weatherproof housings, if provided, shall be permitted to be placed at a distance no less than that specified during the fire test from a wall constructed of the same material. * Where calculations have shown that a fire within the engine enclosure will not ignite structures, the engine shall be permitted to be placed at a distance no less than that specified in the calculations. combustible materials. The first draft language does not bring clarity to the code. SwRI, an OSHA NRTL, has performed full scale engine enclosure testing for generator manufacturers and has certified through listing and labeling which generator manufacturer enclosures are approved as meeting the requirement in Clause 1 of 4.1.4.1.2. Clause 2 of 4.1.4.1.2 does not state what approved calculations are acceptable and who is deemed qualified to perform these calculations. The States are required to participate in the OSHA safety programs or substitute their own safety programs. The State is the authority having jurisdiction and the State can approve their own recognized testing laboratory. Related Public Comments for This Document Related Comment Public Comment No. 1-NFPA 37-2016 [Section No. 4.1.3] First Revision No. 1-NFPA 37-2015 [Section No. 4.1.4] Relationship NFPA 37 Public Comment Responses Page 10 of 32

1 of 30 11/4/2016 3:05 PM Submitter Full Name: Brian Baughman Organization: Generac Power Systems Submittal Date: Wed Mar 02 17:33:47 EST 2016 Committee Rejected but see related SR Action: Resolution: SR-16-NFPA 37-2016 Statement: This section was revised to be consistent with section 4.1.3. If a calculation procedure is used, it must be acceptable to the AHJ, so these do not need to be specified here. Although calculations may have some limitations, they provide an alternative to performing full scale fire tests. NFPA 37 Public Comment Responses Page 11 of 32

2 of 30 11/4/2016 3:05 PM Public Comment No. 13-NFPA 37-2016 [ Section No. 4.1.4.1 ] 4.1.4.1 Engines, and their weatherproof housings, if provided, that are installed outdoors shall be located at least 1.5 m (5 ft) from openings in walls and at least 1.5 m (5 ft) from combustible structures except as provided in 4.1.4.1.1 or 4.1.4.1.2 4.1.4.1.1 A clearance less than 1.5 m (5 ft) shall be permitted where all portions of structures that are closer than 1.5 m (5 ft) from the engine enclosure have a fire resistance rating of at least 1 hour. 4.1.4.1.2 A clearance less than 1.5 m (5 ft) shall be permitted where it has been demonstrated by one of the following methods acceptable to the authority having jurisdiction that a fire within the enclosure will not ignite structures: (1) (2) * Where a full-scale fire test has shown that the complete consumption of the combustibles within the enclosure will not ignite structures, the engine shall be permitted to be placed at a distance no less than that specified during the fire test from a wall of the same material. * Where calculations have shown that a fire within the engine enclosure will not ignite structures, the engine shall be permitted to be placed at a distance no less than that specified in the calculations. I fully support the proposed language. First Revision No. 1-NFPA 37-2015 [Section No. 4.1.4] Submitter Full Name: Marcelo Hirschler Organization: GBH International Submittal Date: Wed May 11 19:31:29 EDT 2016 Committee Action: Rejected Resolution: There were no actionable recommendations. NFPA 37 Public Comment Responses Page 12 of 32

3 of 30 11/4/2016 3:05 PM Public Comment No. 20-NFPA 37-2016 [ Section No. 4.1.4.1.2 ] 4.1.4.1.2 A clearance less than 1.5 m (5 ft) shall be permitted where it has been demonstrated by one of the following methods acceptable to the authority having jurisdiction that a fire within the enclosure will not ignite structures: (1) (2) * Where a full-scale fire test has shown that the complete consumption of the combustibles within the enclosure will not ignite structures, the engine shall be permitted to be placed at a distance no less than that specified during the fire test from a wall of the same material. * Where calculations have shown that a fire within the engine enclosure will not ignite structures, the engine shall be permitted to be placed at a distance no less than that specified in the calculations. Calculations to predict the results of a fire inside the enclosure of an engine generator are limited in scope. Limited in scope, to the effect of the combustible materials that are a part of the engine generator construction. However, the combustibles that are a part of the engine generator construction are not the only combustibles that can burn inside the enclosure once ignited. In particular, there is a fuel source attached to the engine generator that is routed into the enclosure as well. The most common types of fuel sources are propane (liquid or vapor), natural gas, or diesel fuel. If the fuel source is natural gas the supply is unlimited. Propane and diesel fuel as a fuel source are limited by the size of the supply tank but usually have an adequate supply to flow for many hours. Depending on whether the unit is running or not, the Automatic Safety Shutoff Valves (ASSVs) will be open (engine running) or closed (engine not running). If the engine is running, the ASSVs are open, when the fuel lines and other fuel containing parts are consumed the fuel will enter the compartment and be available to burn. The fuel burning will add a significant amount of energy to the enclosure and heat load that is to be contained within the enclosure. Normally the engine will stop when the fuel lines are consumed due to the lack of fuel to power the engine. The ASSVs will close if they can. The ability of the ASSVs to close is dependent on if the fire has damaged the internal sealing components. The ASSVs sealing components are usually made from rubber or a similar material and melt at a relatively low temperature. Regardless of whether the engine is running or not the fire inside the enclosure can potentially comprise the gas shutoff valve and allow the fuel supply to enter the enclosure and fuel the fire. It would be very difficult to calculate the effect of this additional fuel source, rate of burn, path of burn and the overall effect on the ability of the engine generator enclosure to contain the fire. This is why the calculations to predict the results of a fire inside the enclosure of an engine generator are limited in scope. Since this approach is limited in scope, section 4.1.4.1.2 (2) should be eliminated from the 2018 version of NFPA 37. NFPA 37 Public Comment Responses Page 13 of 32

4 of 30 11/4/2016 3:05 PM First Revision No. 1-NFPA 37-2015 [Section No. 4.1.4] Submitter Full Name: Jeff Jonas Organization: Generac Power Systems Submittal Date: Wed May 18 15:57:48 EDT 2016 Committee Rejected but see related SR Action: Resolution: SR-16-NFPA 37-2016 Statement: This section was revised to be consistent with section 4.1.3. If a calculation procedure is used, it must be acceptable to the AHJ, so these do not need to be specified here. Although calculations may have some limitations, they provide an alternative to performing full scale fire tests. NFPA 37 Public Comment Responses Page 14 of 32

5 of 30 11/4/2016 3:05 PM Public Comment No. 15-NFPA 37-2016 [ Section No. 4.3 ] 4.3* Hazardous Locations. In hazardous locations, engines that neither compress a flammable gas nor pump a flammable liquid shall meet the following three criteria: (1) They shall be installed in a an enclosure or room of fire-resistive construction. (2) They shall be ventilated from a nonhazardous outside area. (3) They shall have outside access only defined emergency egress path(s). Larger gensets and turbines today are being provided with large, purpose designed free standing enclosures that are not an engine room as used in NFPA 37. Engine room as used in NFPA 37 implies a portion of a building that is walled off to provide a separate space in which an engine / turbine is placed; much like we wall off Office or Bathroom spaces in a building. The task group has provided an expanded discussion of enclosures at Annex section A.3.3.2 that considers and distinguishes between the close fitting weather covers that are provided for small gensets and microturbines; and the large, purpose designed, free standing enclosures, purpose designed packages and containerized assemblies that are provided with larger genset and industrial turbine installations. Recognizing that the free standing purpose designed enclosures, packages and containers for gensets and turbines are being placed as an assembly within a larger building, it is usually not practical (nor is it being provided!) for personnel working within those structures to have a direct exit to outdoors; rather they exit to the larger building from which an exit path to the outdoors must be provided This change recognizes the evolution in installation configurations. Related Public Comments for This Document Related Comment Public Comment No. 16-NFPA 37-2016 [Section No. 4.5.1] Public Comment No. 17-NFPA 37-2016 [Section No. 4.5.2] Public Comment No. 18-NFPA 37-2016 [Section No. A.3.3.2] First Revision No. 20-NFPA 37-2015 [Section No. 4.3] Relationship Submitter Full Name: Larry Danner Organization: GE Power & Water NFPA 37 Public Comment Responses Page 15 of 32

6 of 30 11/4/2016 3:05 PM Submittal Date: Mon May 16 08:08:58 EDT 2016 Committee Rejected but see related SR Action: Resolution: SR-6-NFPA 37-2016 Statement: The committee determined that the emergency egress path should be acceptable to the AHJ so as not to lead to a more hazardous area. The term enclosure was added because larger gensets and turbines today are being provided with large, purposedesigned, free-standing enclosures that are not an engine room as used in NFPA 37. Engine room as used in NFPA 37 implies a portion of a building that is walled off to provide a separate space in which an engine/turbine is placed. NFPA 37 Public Comment Responses Page 16 of 32

7 of 30 11/4/2016 3:05 PM Public Comment No. 16-NFPA 37-2016 [ Section No. 4.5.1 ] 4.5.1 Electrical installations in rooms, or enclosures containing engines shall comply with NFPA 70. enclosures added here for consistency with the changes made to 4.3 and the expanded discussion of enclosures provided in Annex A.3.3.2. Related Public Comments for This Document Related Comment Public Comment No. 15-NFPA 37-2016 [Section No. 4.3] First Revision No. 20-NFPA 37-2015 [Section No. 4.3] Relationship Change for Consistency between clauses Submitter Full Name: Larry Danner Organization: GE Power & Water Submittal Date: Mon May 16 08:22:10 EDT 2016 Committee Rejected but see related SR Action: Resolution: SR-8-NFPA 37-2016 Statement: This revision clarifies that, regardless of location, the electrical installation is required to meet the provisions of NFPA 70. NFPA 37 Public Comment Responses Page 17 of 32

8 of 30 11/4/2016 3:05 PM Public Comment No. 17-NFPA 37-2016 [ Section No. 4.5.2 ] 4.5.2 Engine rooms, enclosures, or other locations shall not be classified as hazardous locations as defined in Article 500 of NFPA 70, solely by reason of the engine fuel, lubricating oil, or hydraulic fluid. enclosures added here for consistency with the changes made to 4.3 and the expanded discussion of enclosures provided at Annex section A..3.3.2. Related Public Comments for This Document Related Comment Public Comment No. 15-NFPA 37-2016 [Section No. 4.3] First Revision No. 20-NFPA 37-2015 [Section No. 4.3] Relationship Provide consistency with Public Comment 15 Submitter Full Name: Larry Danner Organization: GE Power & Water Submittal Date: Mon May 16 08:26:23 EDT 2016 Committee Accepted Action: Resolution: SR-9-NFPA 37-2016 Statement: The term enclosures is added to be consistent with the changes made to 4.3 (see SR-6) and the expanded discussion of enclosures provided in A.3.3.2 (see SR-7). NFPA 37 Public Comment Responses Page 18 of 32

9 of 30 11/4/2016 3:05 PM Public Comment No. 4-NFPA 37-2016 [ Section No. 5.1 ] 5.1* Gas Piping Gas Train Materials and Fittings and Gas Piping Systems. 5.1.1 Gas piping system from the point of delivery to the equipment isolation valve shall be installed in accordance with the following methods: (1) All fuel gas piping systems at service pressures equal to or less than a gauge pressure of 860 kpa (gauge pressure of 125 psi) shall be installed in accordance with NFPA 54. (2) All fuel gas p iping systems at service pressures in excess of a gauge pressure of 860 kpa (gauge pressure of 125 psi), other than LP-Gas systems, shall be installed in accordance with ANSI/ASME B31.3, Process Piping. (3) LP-Gas p iping systems, whether liquid or vapor phase, shall be installed in accordance with the provisions of NFPA 58. 5.1.2* Plastic pipe on the gas train or within the gas piping system shall not be used to carry fuel within a room housing an engine(s). 5.1.3 Approved metallic flexible connectors on a gas train or within the gas piping system shall be permitted for protection against damage caused by settlement, vibration, expansion, contraction, or corrosion. 5.1.4 Approved nonmetallic connectors on a gas train or within the gas piping system shall be permitted for protection against damage caused by settlement, vibration, expansion, contraction, or corrosion except for LP-Gas in the liquid phase. 5.1.5* Connectors used on the gas train for vibration dampening shall be properly anchored and installed according to manufacturer's instructions. The term fuel gas piping system in NFPA 54 is all piping upstream of the equipment isolation valve. NPFA 54 defines piping system as All pipe, tubing, valves, and fittings from the point of delivery to the outlets of the appliance shutoff valve (aka equipment isolation valve). All piping that is downstream of the equipment isolation valve is part of the fuel gas train, which is part of the engine and is not considered fuel gas piping. 2) The NFPA 54 reference is circuitous; NPFA 86 references a standard, whose scope does not cover and should not be applied to a fuel gas train of the oven. Thus, unintentional conflicts can occur. For example, NPFA 54 (2015), 5.6 Acceptable Piping Materials and Joining Methods required that non-ferrous flanged (i.e. aluminum flanged connections) comply with ANSI/ASME B16.24, Cast Copper Alloy Pipe Flanges and Flanged Fittings: Classes 150, 300, 600. 900, 1500, and 2500 (see NFPA 54, paragraph 5.6.10.1.3). This standard only permits flat face flanges. For design of gas trains, the use of Aluminum valves with raised face flanges has been standard since NFPA 37 Public Comment Responses Page 19 of 32

0 of 30 11/4/2016 3:05 PM the 1930 s. Such valves are permitted in NPFA 86, NFPA 85, CDS-1, UJL 795, UL 2200, and a whole host of ANSI standards, and the intent of the NFPA 54 reference is not to prohibit the use of aluminum valves with raised face flanges. Committee Input No. 10-NFPA 37-2015 [Section No. 5.1.1] Submitter Full Name: Kevin Carlisle Organization: Karl Dungs, Inc. Submittal Date: Wed Mar 16 17:23:27 EDT 2016 Committee Rejected but see related SR Action: Resolution: SR-12-NFPA 37-2016 Statement: This revision was made to eliminate unintended conflicts between NFPA 54 and NFPA 37. NFPA 37 Public Comment Responses Page 20 of 32

1 of 30 11/4/2016 3:05 PM Public Comment No. 11-NFPA 37-2016 [ Section No. 5.6 ] 5.6 Overpressure Protection. 5.6.1 Overpressure protection shall be required for any fuel gas train subject to either of the following conditions : LP-Gas piping systems, whether liquid or vapor phase, in accordance with the provisions of NFPA 58. Fuel gas piping systems at service pressures in excess of a gauge pressure of 860 kpa ((gauge pressure of 125 psi), other than LP-Gas systems, in accordance with ANSI/ASME B31.3, Process Piping. Fuel gas piping systems and fuel gas trains, handling pressures equal to or less than a gauge pressure of 860 kpa (gauge pressure of 125 psi), when the supply pressure exceeds a gauge pressure of 14 kpa (gauge pressure of : (1) The inlet gas pressure exceeds both 14 kpa ( 2 psi) and the protected pressure already provided to the fuel gas train is greater than the maximum allowable operating pressure rating of any fuel gas train component. 5.6.1.1 When an overpressure protection device is required in 5.6.1(3), the overpressure protection device shall be set to provide a protected pressure so that the following pressures are not exceeded: (1) If the component s maximum allowable operating pressure rating is a gauge pressure less than 83 kpa (gauge pressure less than 12 psi), the allowable overpressure is 50 percent over the maximum allowable operating pressure rating of the component. (2) If the component s maximum allowable operating pressure rating is a gauge pressure equal to or greater than 83 kpa but less than 414 kpa (gauge pressure equal to or greater than 12 but less than 60 psi), the allowable overpressure is a gauge pressure of 41 kpa (gauge pressure of 6 psi) over the maximum allowable operating pressure rating of the component. (3) If the component s maximum allowable operating pressure rating is a gauge pressure equal to or greater than 414 kpa but less than or equal to 860 kpa (gauge pressure equal to or greater than 60 psi), but less than or equal to 125 psi), the allowable overpressure is 10 percent over the maximum allowable operating pressure rating of the component. (1) rated pressure of any downstream component (2) The failure of a single upstream line pressure regulator results in an inlet gas pressure exceeding the rated pressure of any downstream component NFPA 37 Public Comment Responses Page 21 of 32

2 of 30 11/4/2016 3:05 PM 5.6.1.2 1 The overpressure protection device required in 5.6.1.1(3) shall also comply with the following: (1) The overpressure protection device shall be any one device permitted in Section 5.9 of NFPA 54. The gas piping system or fuel gas train shall be designed and installed such that the (1) * There shall be an active or passive means by which the activation of the overpressure protection device is in a continuous pressure protection mode, and the overpressure condition is (2) detectable. Pressure relief valves, where (1) Where a pressure relief valve(s) is used as the overpressure protection device, the relief valve and all connected vent piping shall be sized to fully relieve the required volume of gas in order to provide a protected pressure in accordance with (2) accommodate the maximum anticipated flow due to the failure of the nearest upstream line pressure regulator. Add annex A. 5.6.1.1 under the following conditions: The upstream pressure regulator in the gas piping system has failed in the wide open position. The required relieving pressure of the relief valve is based on the protected pressure to the upstream pressure regulator in the gas piping system. The pressure limits in this section are consistent with 49 CFR Part 192.201, Required Capacity of Pressure Relieving and Limiting Stations A.5.6.1.1.1(2) An example of active means is an alarm or light notification. An example of passive means is a manual reset. Additional Proposed Changes NFPA_37_Section_5_6_- _Revisions_FINAL_TASK_GROUP.docx File Name Description Approved This is the work of the task group New definitions needed in order to know how to apply the requirement, and this resulted in changes to the wording. Also, scope was limited to the gas train since NFPA 37 does not cover gas piping. Therefore, task group feels that failure of a service regulator need not be needed to drive the requirement of an OPD since the issue is really about failure of line regulator within the upstream gas piping system First Revision No. 11-NFPA 37-2015 [New Section after 5.5] NFPA 37 Public Comment Responses Page 22 of 32

New 1.7 1.7 Pressure Measurement. All pressures expressed in this document are gauge pressures unless specifically noted otherwise. Removed Definitions Remove definition of Protected Pressure that was added in the First Draft New Definitions Inlet Gas Pressure: The pressure at the outlet of the equipment isolation valve. Line Pressure Regulator: A pressure regulator placed in a gas line between the service regulator and the appliance regulator [54, 2015] Rated Pressure. The maximum internal and external pressures that the materials, devices, or components are designed to contain or control. Revised Definitions Service Regulator. A pressure regulator installed by the serving gas supplier to reduce and limit the service line gas pressure to delivery pressure. [54, 2015] Revise Section 5.6 5.6 Overpressure Protection. 5.6.1 Overpressure protection shall be required for any fuel gas train subject to either of the following conditions: 5.6.1.1* (a) The inlet gas pressure exceeds both 14 kpa (2 psi) and the rated pressure of any downstream component (b) The failure of a single upstream line pressure regulator results in an inlet gas pressure exceeding the rated pressure of any downstream component When an overpressure protection device is required in 5.6.1(2), it shall be set so that the following pressures are not exceeded: (1) When the rated pressure of any component is less than 83 kpa (12 psi), the set point of the overpressure protection device shall not exceed 150 percent of the rated pressure of the lowest rated component. (2) When the rated pressure of any component is equal to or greater than 83 kpa (12 psi) but less than 414 kpa (60 psi), the set point of the overpressure protection device shall not exceed 41 kpa (6 psi) above the rated pressure of the lowest rated component. (3) When the rated pressure of any component is equal to or greater than 414 kpa (60 psi), the set point of the overpressure protection device shall not exceed 110 percent of the rated pressure of the lowest rated component. 5.6.1.1.1 The overpressure protection device required in 5.6.1.1(3) shall also comply with the following: (1) The overpressure protection device shall be any one device permitted in Section 5.9 of NFPA 54. NFPA 37 Public Comment Responses Page 23 of 32

(2) * There shall be an active or passive means by which the activation of the overpressure protection device is detectable. (3) Where a pressure relief valve(s) is used as the overpressure protection device, the relief valve and all connected vent piping shall be sized to accommodate the maximum anticipated flow due to the failure of the nearest upstream line pressure regulator. A.5.6.1.1 The pressure limits in this section are consistent with 49 CFR Part 192.201, Required Capacity of Pressure Relieving and Limiting Stations A.5.6.1.1.1(2) An example of active means is an alarm or light notification. An example of passive means is a manual reset. NFPA 37 Public Comment Responses Page 24 of 32

3 of 30 11/4/2016 3:05 PM Submitter Full Name: Kevin Carlisle Organization: Karl Dungs, Inc. Submittal Date: Fri May 06 15:42:38 EDT 2016 Committee Rejected but see related SR Action: Resolution: SR-14-NFPA 37-2016 Statement: This revision addresses the gap in the requirements of NFPA 54 (2015) for overpressure protection between 2 psi and 125 psi. NFPA 37 Public Comment Responses Page 25 of 32

4 of 30 11/4/2016 3:05 PM Public Comment No. 18-NFPA 37-2016 [ Section No. A.3.3.2 ] A.3.3.2 Enclosure. An enclosure is not considered to be a room. An enclosure can be a simple weather protection cover (as typically provided for a small outdoor genset) that cannot be entered by a person, UL2200 is often applied for the design of these enclosures. An enclosure can also be a purpose designed structure provided with an engine or a room. turbine by the manufacturer, which may have provisions for personnel entry to facilitate inspection or maintenance. Some gensets and turbines are provided in a fully self-contained package that may be in the form of a purpose designed structure or a standard shipping container. Although purpose designed structures and packages may be placed within a building, they remain independent structures that are not an integral part of the building and, therefore, do not constitute an engine room as used in NFPA 37. These purpose designed structures / packages may provide any of, but are not limited to, the following functions: (1) Environmental protection (2) Noise containment (3) Fire protection (4) Heat rejection / ventilation (5) Human protection (6) Hazardous area classification This expanded discussion for the term enclosure a) recognizes and details the current variety of installations for gensets and turbines, and b) provides clarity on the subject to users of NFPA 37. Related Public Comments for This Document Related Comment Public Comment No. 15-NFPA 37-2016 [Section No. 4.3] Public Comment No. 19-NFPA 37-2016 [Section No. B.1.2.9] First Revision No. 20-NFPA 37-2015 [Section No. 4.3] Relationship Provides an updated discussion of "enclosur" as used in Public Comment 15 Submitter Full Name: Larry Danner Organization: GE Power & Water NFPA 37 Public Comment Responses Page 26 of 32

5 of 30 11/4/2016 3:05 PM Submittal Date: Mon May 16 08:31:28 EDT 2016 Committee Rejected but see related SR Action: Resolution: SR-7-NFPA 37-2016 Statement: The revised definition and expanded discussion for the term enclosure recognizes and details the current variety of installations for gensets and turbines, and provides clarity on the subject to users of NFPA 37. NFPA 37 Public Comment Responses Page 27 of 32

6 of 30 11/4/2016 3:05 PM Public Comment No. 12-NFPA 37-2016 [ Section No. A.4.1.4.1.2(2) ] A.4.1.4.1.2(2) The calculation procedure procedures in Chapter 10 of NFPA 555 is contain a procedure similar to the Radiant Ignition of a Near Fuel algorithm in NIST s Fire Protection Engineering Tools for Hazard Estimation (FPETool) for calculating ignition from a nearby fire. It is a sound, engineering-based method of predicting the risk radiative ignition of ignition from a fire a material not in direct contact with a flame. The values in 4.1.4 and the reference to the NFPA 555 calculation method are the result of the calculations presented to the technical committee in 1996. The calculations treated an engine fire as a vertical cylinder. The values in 4.1.4 changed somewhat in the 1998 edition of NFPA 37 based on those calculations. They are reasonably consistent with the requirements of the Building Officials and Code Administrators (BOCA) National Building Code, which was in effect at the time. The committee wanted to include a performance alternative in NFPA 37. The reference in this annex section to the NFPA 555 method provides guidance on how to evaluate proposed alternatives. I fully support the concept in this annex note. The proposed change is basically editorial. Chapter 10 of NFPA 555 contains more than one procedure for evaluating radiative ignition. The procedures do not address risk but hazard, which is the potential for harm. The charging paragraph of Chapter 10 of NFPA 555 is shown below. 10.1 Methods/Tools. A set of analytical methods or tools is needed to provide a means for performing the evaluations embodied by the definitions in Section 8.3. In particular, methods are needed to predict the heating to ignition of materials contained within a fuel package as well as the radiative heat transfer to the material from other fuel packages or the hot gas layer. This chapter focuses on the radiative ignition of a material not in direct contact with a flame. First Revision No. 1-NFPA 37-2015 [Section No. 4.1.4] First Revision No. 23-NFPA 37-2015 [Section No. A.4.1.4(2)] Submitter Full Name: Marcelo Hirschler Organization: GBH International Submittal Date: Wed May 11 19:22:21 EDT 2016 NFPA 37 Public Comment Responses Page 28 of 32

7 of 30 11/4/2016 3:05 PM Committee Rejected but see related SR Action: Resolution: SR-16-NFPA 37-2016 Statement: This section was revised to be consistent with section 4.1.3. If a calculation procedure is used, it must be acceptable to the AHJ, so these do not need to be specified here. Although calculations may have some limitations, they provide an alternative to performing full scale fire tests. NFPA 37 Public Comment Responses Page 29 of 32

8 of 30 11/4/2016 3:05 PM Public Comment No. 5-NFPA 37-2016 [ Section No. A.5.1 ] A.5.1 Gaseous-fueled engines are those engines in which the fuel supply is delivered to the engine in vapor form, including, but not limited to, the following: (1) Natural gas (2) Compressed natural gas (CNG) (3) Propane (4) LP-Gas (5) Mixed gas (6) Manufactured gas and syngas (7) Biogas (e.g., landfill and digester gas) (for biogas applications, see CSA B149.6-15, Code for Digester Gas and Landfill Gas Installations for Piping Materials and Practices) Liquefied natural gas (LNG), for the purpose of Chapter 5, can be considered a gaseous fuel for engines. Piping systems supplying gaseous fuels should be designed to minimize piping failure. Several examples of methods for minimizing piping failure are as follows: (1) Welded pipe joints should be used where practical. Threaded couplings and bolted flanges should be assembled in accordance with the manufacturer's requirements. (2) If rigid metal piping is used, it should be designed to deflect with the engine in any direction. Properly designed flexible connectors are an alternative in high-vibration areas, such as between rigid pipe supply lines and manifolds or other points of connection to the engine. (3) Rigid piping connected directly to the engine should be supported so that failures will not occur due to the natural frequency of the piping coinciding with the rotational speed of the engine. Care should be taken in the design of pipe supports to avoid vibrations. For guidance on the evacuation/purging, charging, and commissioning of the combustible gas supply in the piping upstream of the equipment isolation valve, refer to NFPA 56. During commissioning, the gas train should be inspected for leaks. Typically, inspection and leak tests of a gas train is performed at a pressure not less than their normal operating pressure using the test method detailed in NFPA 54. Leak testing of a gas piping system is detailed in NFPA 54. I suggest we have some recommendation in the Annex about using NFPA 54 as the method to test a gas train for external tightness. Public Input No. 23-NFPA 37-2015 [Section No. 5.1.1] NFPA 37 Public Comment Responses Page 30 of 32

9 of 30 11/4/2016 3:05 PM Submitter Full Name: Kevin Carlisle Organization: Karl Dungs, Inc. Submittal Date: Fri Apr 08 16:56:22 EDT 2016 Committee Action: Resolution: Rejected but held The committee recognizes that additional clarity might be needed with respect to commissioning of gas trains. However, this is new material and the committee will address this in the next revision cycle. NFPA 37 Public Comment Responses Page 31 of 32

0 of 30 11/4/2016 3:05 PM Public Comment No. 19-NFPA 37-2016 [ Section No. B.1.2.9 ] B.1.2.9 UL Publications. Underwriters Laboratories Inc., 333 Pfingsten Road, Northbrook, IL 60062-2096. UL 2080, Fire Resistant Tanks for Flammable and Combustible Liquids, 2000. UL 2085, Protected Aboveground Tanks for Flammable and Combustible Liquids, 1997, revised 2010. UL2200, Standard for Safety, Stationary Engine Generator Assemblies, 2012, revised 2015 Added UL 2200 since this document was referenced in the expanded Annex A.3.3.2 discussion. Related Public Comments for This Document Related Comment Public Comment No. 18-NFPA 37-2016 [Section No. A.3.3.2] First Revision No. 20-NFPA 37-2015 [Section No. 4.3] Relationship Reference made to UL 2200 in Public Comment 18 Submitter Full Name: Larry Danner Organization: GE Power & Water Submittal Date: Mon May 16 08:40:08 EDT 2016 Committee Accepted Action: Resolution: SR-11-NFPA 37-2016 Statement: The reference to UL 2200 is added because this document is referenced in the expanded Annex A.3.3.2 discussion. NFPA 37 Public Comment Responses Page 32 of 32