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TECHNICAL COMMITTEE ON INTERNAL COMBUSTION ENGINES AGENDA Technical Committee on Internal Combustion Engines NFPA 37 Second Draft Meeting GE Power and Water, Greenville, SC Tuesday, March 5, 2013, 8:00 AM to 2:15 PM Tuesday, March 5, 2013, 3:00 PM – Facility Tour Wednesday, March 6, 2013, 8:00 AM to 3:00 PM 1. Call to Order. 2. Introduction of Attendees. Update of Committee Roster. (Attachment A1) 3. Approval of Minutes of Last Meeting. (May 2013, NFPA, Quincy MA) (Attachment A2) 4. Report of Committee Chair. 5. Report of Staff Liaison. Review of Technical Committee Scope. (Attachment A3) Review of Technical Committee Membership. (Attachment A3) Enforcer Participation & Alternate Member Emphasis Programs. Review of Fall 2013 Document Revision Schedule. (Attachment A4) 6. Status of NFPA 56PS – Scheduled for Adoption at June 2013 NFPA Conference. (L. Danner) 7. Proposed Tentative Interim Amendment to NFPA 37, 3.3 & 6.6.3. (Attachment A5) [Discussion by D. McMenamin, Consultant to Verizon Wireless] 8. Proposed Tentative Interim Amendment to NFPA 37-2010, 9.3.3. (Attachment A6) [Authorized at May 2012 Meeting] 9. Aero (Thin-Wall) Turbines – Report of Task Group. (Attachment A7) 10. Review and Act on First Draft Report Committee Inputs on NFPA 37-2010. CI12 / 5.2.1 (Attachment A8) [See Public Comment 13] CI14 / 5.3.1.1 (Attachment A9) [See Public Comment 11] CI13 / 5.2.2 (Attachment A10) [See Public Comment 12] CI4 / 1.3.3 (Attachment A11) [Contingent on Disposition of CI5] CI3 / 4.4.1.1 (Attachment A11) [No Input Received] 11. Review and Act on Comments Received on First Draft Report on NFPA 37-2010. (Attachment A12) 12. Review and Additional Issues Regarding 2010 Edition of NFPA 37. (Attachment A13)

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TECHNICAL COMMITTEE ON INTERNAL COMBUSTION ENGINES

AGENDA

Technical Committee on Internal Combustion Engines

NFPA 37 Second Draft Meeting GE Power and Water, Greenville, SC

Tuesday, March 5, 2013, 8:00 AM to 2:15 PM Tuesday, March 5, 2013, 3:00 PM – Facility Tour Wednesday, March 6, 2013, 8:00 AM to 3:00 PM

1. Call to Order. 2. Introduction of Attendees. Update of Committee Roster. (Attachment № A1) 3. Approval of Minutes of Last Meeting. (May 2013, NFPA, Quincy MA) (Attachment № A2) 4. Report of Committee Chair. 5. Report of Staff Liaison.

Review of Technical Committee Scope. (Attachment № A3) Review of Technical Committee Membership. (Attachment № A3) Enforcer Participation & Alternate Member Emphasis Programs. Review of Fall 2013 Document Revision Schedule. (Attachment № A4)

6. Status of NFPA 56PS – Scheduled for Adoption at June 2013 NFPA Conference. (L. Danner) 7. Proposed Tentative Interim Amendment to NFPA 37, 3.3 & 6.6.3. (Attachment № A5)

[Discussion by D. McMenamin, Consultant to Verizon Wireless] 8. Proposed Tentative Interim Amendment to NFPA 37-2010, 9.3.3. (Attachment № A6)

[Authorized at May 2012 Meeting] 9. Aero (Thin-Wall) Turbines – Report of Task Group. (Attachment № A7) 10. Review and Act on First Draft Report Committee Inputs on NFPA 37-2010.

CI12 / 5.2.1 (Attachment № A8) [See Public Comment 13] CI14 / 5.3.1.1 (Attachment № A9) [See Public Comment 11] CI13 / 5.2.2 (Attachment № A10) [See Public Comment 12] CI4 / 1.3.3 (Attachment № A11) [Contingent on Disposition of CI5] CI3 / 4.4.1.1 (Attachment № A11) [No Input Received]

11. Review and Act on Comments Received on First Draft Report on NFPA 37-2010. (Attachment № A12) 12. Review and Additional Issues Regarding 2010 Edition of NFPA 37. (Attachment № A13)

13. Recent Correspondence & Communications. (NONE) 14. Other Old Business. (NONE) 15. New Business.

Termination of Normal Vents for Sub-Base Tanks. [Task Group for Next Document Revision Cycle – Per May 2012 Meeting]

16. Schedule Next Meeting(s). 17. Adjournment.

Address List No PhoneInternal Combustion Engines INT-AAA

Robert P. Benedetti02/19/2013

INT-AAA

Clifford C. Roberts

ChairAmerican International Group, Inc. (AIG)15019 Eaglerise DriveLithia, FL 33547

I 10/6/2000INT-AAA

Stephen P. Wetter

SecretaryCaterpillar, Inc.Electric Power Division560 Rehoboth RoadGriffin, GA 30224

M 1/1/1996

INT-AAA

James B. Biggins

PrincipalGlobal Risk Consultants Corporation15732 West Barr RoadManhattan, IL 60442-9012

SE 1/1/1992INT-AAA

Lawrence M. Danner

PrincipalGeneral Electric, Energy300 Garlington RoadGTTC Room 200DGreenville, SC 29615-0648

M 7/19/2002

INT-AAA

Kenneth M. Elovitz

PrincipalEnergy Economics, Inc.26 Elm StreetFoxboro, MA 02035

SE 1/1/1994INT-AAA

Fred L. Hildebrandt

PrincipalJanus Fire Systems1102 Rupcich Drive, Millennium ParkCrown Point, IN 46307Fire Suppression Systems Association

IM 8/2/2010

INT-AAA

Zuhair M. Ibrahim

PrincipalExponent, Inc.5401 McConnell AvenueLos Angeles, CA 90066

SE 3/4/2009INT-AAA

David Nieman

PrincipalBechtel Power Corporation5275 Westview DriveFrederick, MD 21703Alternate: Keegan M. Kinney

SE 8/5/2009

INT-AAA

Steven H. Pasternack

PrincipalIntertek Testing Services3933 US Route 11Cortland, NY 13045

RT 4/17/2002INT-AAA

Owen M. Preston

Principal3221 Blair DrivePalatka, FL 32177

SE 7/1/1994

INT-AAA

Y. R. Reddy

PrincipalR-B Pumps, Inc.PO Box 557Baxley, GA 31513

U 4/1/1994INT-AAA

John E. Reiter

PrincipalAES Corporation237 Tall Pines DriveMineral, VA 23117Alternate: Kow Ken Sun

U 7/19/2002

INT-AAA

Richard Scott

PrincipalChubb Group of Insurance CompaniesOne Financial CenterBoston, MA 02111-2697

I 1/1/1994INT-AAA

Milan Tretinjak

PrincipalSolar Turbines Incorporated9330 Sky Park Court, MZ-CSC-24San Diego, CA 92123Alternate: Gerard J. Schnee

M 4/17/2002

1

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Attachment No. A1

Address List No PhoneInternal Combustion Engines INT-AAA

Robert P. Benedetti02/19/2013

INT-AAA

Bruce J. Wertz

PrincipalPower Plant Management Consulting LLC4332 Austin Farm TrailAcworth, GA 30101

SE 8/9/2011INT-AAA

Keegan M. Kinney

AlternateBechtel Power Corporation5275 Westview DriveFrederick, MD 21703Principal: David Nieman

SE 10/29/2012

INT-AAA

Gerard J. Schnee

AlternateSolar Turbines Incorporated9250 Skypark CourtSan Diego, CA 92123Principal: Milan Tretinjak

M 10/27/2009INT-AAA

Kow Ken Sun

AlternateAES CorporationRua XV De Novembro, 1510Centro, ParanaMarechal Candido Rondon, 85960 BrazilPrincipal: John E. Reiter

U 10/29/2012

INT-AAA

Robert P. Benedetti

Staff LiaisonNational Fire Protection Association1 Batterymarch ParkQuincy, MA 02169-7471

7/2/2002

2

TECHNICAL COMMITTEE ON INTERNAL COMBUSTION ENGINES

MINUTES of MEETING

Technical Committee on Internal Combustion Engines National Fire Protection Association Offices

Quincy, MA May 23 & 24, 2012

I. Attendance

J. B. Biggins, Global Risk Consultants Corporation L. M. Danner, General Electric Energy K. M. Elovitz, Energy Economics, Inc. F. L. Hildebrandt, Janus Fire Systems D. Nieman, Bechtel Power Corporation S. H. Pasternack, Intertek Testing Services O. M. Preston, Palatka, FL C. C. Roberts, Chartis Global Marine & Energy, CHAIR G. J. Schnee, Solar Turbines Incorporated R. Shaffer, IEA Incorporated S. P. Wetter, Caterpillar Inc., SECRETARY R. P. Benedetti, National Fire Protection Association, STAFF LIAISON GUESTS: K. Carlisle, Karl Dungs, Incorporated G. Colonna, NFPA D. Duval, NFPA J. LaMore, Elster Kromschroder D. Matthews, NFPA N. Pearce, NFPA L. Swalec, NFPA

II. Minutes 1. The Meeting was called to order at 8:00 AM on May 23, 2012. The Staff Liaison presented an

overview of the new web-based document revision system. 2. Attendees introduced themselves and the Technical Committee roster was updated as needed.

A new roster will be posted to the Technical Committee’s web page. 3. The Minutes of the last meeting (March 2011 web conference) were unanimously approved as

submitted. 4. Technical Committee Chair Cliff Roberts reported on the following items:

Tentative Interim Amendment 10-1, which amended Paragraphs 11.4.4.1.1 and 11.4.4.2 of NFPA 37.

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Attachment No.A2

Edison Electric Institute Task Group report on changes to NFPA 85 that might impact NFPA 37. 5. The Staff Liaison reported on the following items:

Technical Committee Scope Statement. The Technical Committee agreed no changes are necessary.

Technical Committee Membership. There is a need for members in categories other than Special Expert.

The Enforcer Participation Emphasis Program. Alternate Member Emphasis Program. Review of Fall 2013 Document Revision Schedule.

6. Larry Danner reported on the status of NFPA 56PS, Standard for Fire and Explosion Prevention

During Cleaning and Purging of Flammable Gas Piping Systems. He reviewed the KleenEnergy incident and reported that the official version of NFPA 56PS is in the Annual 2013 document revision cycle. The Report on Proposals (ROP) for NFPA 56PS is available for public comment, with a Comment Closing Date of August 31, 2012. The Technical Committee developed a Committee Proposal to reference NFPA 56PS in NFPA 37.

7. Ron Shaffer reported on wind and seismic rules that impact installation of stationary engines and

generator sets. California Office of Statewide Health Planning and Development is requiring shake table testing for critical application engines (hospitals, e.g.) in seismic areas. The Technical Committee developed a Committee Proposal to address this in NFPA 37.

8. The Technical Committee discussed the need for a Tentative Interim Amendment to Subsection 9.3.3

of NFPA 37. It was noted that the text of 9.3.2 in the 2010 edition was to have been an addition, not a replacement. The Technical Committee developed a Committee Proposal to address this by amending Subsection 9.3.3 to read: “9.3.3 The combustion gas turbine starting sequence shall include a purge cycle that will result in a nonflammable atmosphere in the turbine and exhaust system, prior to the start of the ignition sequence and the introduction of fuel.” The Technical Committee also decided to prepare a Tentative Interim Amendment to the same text in the 2010 edition.

9. The Technical Committee heard reports from the Chapter 4 and Chapter 5 Task Group. The former

is incorporated into Agenda Item № 10 and the latter is presented as a formal proposal item in Agenda Item № 11.

10. The Technical Committee reviewed proposed amendments to Chapter 4 of 2010 Edition of NFPA 37.

The proposed amendment to Paragraph 4.1.1.5 was replaced by a proposal submitted by J. Bender. The second proposed amendment was incorporated via a Committee Proposal.

11. The Technical Committee review and took action on all public proposals to amend the 2010 Edition of

NFPA 37. As part of this Agenda Item, the Technical Committee appointed a Task Group to address Aero (thin wall) turbines, said Task Group consisting of Messrs. Hildebrandt (chair), Biggins, Danner, Roberts, and Schnee.

12. The Technical Committee reviewed and took action on additional suggested amendments to NFPA

37, including those from Mr. Carlisle. Two of these failed ballot (amendments to Subsections 5.2.1 and 5.2.2) and were addressed with Committee Inputs to solicit public comment. The Technical Committee directed the Staff Liaison to circulate the letter ballot on the First Revision draft for the proposed 2014 edition of NFPA 37.

13. The Technical Committee reviewed recent correspondence and communications. No issues were

identified. 14. There was no other Old Business requiring the Technical Committee’s attention.

15. Under “New Business”, the Technical Committee discussed the following items:

Air Toxic Rules being proposed by the U. S. Environmental Protection Agency. The Technical Committee determined that this was an information only item.

Differences between NFPA 37 and NFPA 31 with regard to requiring an oil safety valve (OSV). In fact, NFPA 37 recommends an OSV in Annex Item A.6.3.8

Termination of normal breather vents for sub-base tanks. The Technical Committee agreed to establish a Task Group to address this during the next document revision cycle.

The Technical Committee discussed whether Subsection 4.1.4 of NFPA 37 considers an intervening barrier as equivalent to separation distance. The Technical Committee noted that this will be allowed in the next edition of NFPA 37.

Application of Subsection 4.1.2 of NFPA 37 to stationary engines and their fuel tanks in garages. The Technical Committee determined that one of the Chapter 4 Task Group amendments addressed this issue.

Engines in Dedicated Enclosures Installed in Buildings. The Technical Committee determined that this is a building code issue.

Changes in NFPA 85 Provisions for HRSG and Correlation with NFPA 37. Larry Danner described changes to NFPA 85 that allow pre-purge of the exhaust system, if additional safeguards are provided to prevent leakage of fuel into the unit.

16. The Technical Committee scheduled its next meeting for March 12 - 13, 2013, in West Palm Beach

FL area or some other venue that might afford a field visit. 17. The meeting adjourned at 12:00 PM on May 24th.

INT Scope Statement & Member Balance.doc - 2/20/2013

TECHNICAL COMMITTEE ON INTERNAL COMBUSTION ENGINES

SCOPE STATEMENT

This Committee shall have primary responsibility for documents on the fire safety of the installation, operation, and control of internal combustion engines, including gas turbine engines, using all types of fuel, within structures or immediately exposing structures. Responsible for NFPA 37, Standard for the Installation and Use of Stationary Combustion Engines and Gas Turbines.

COMMITTEE MEMBERSHIP BALANCE

Members: 15 M: 3 (20%)* U: 2 (13%) Voting Alternates: 0 I/M: 1 (7%) L/C: L/C: 0 Alternates: 3 R/T: 1 (7%) E: 0

Non-Voting: 0 I: 2 (13%) SE: 6 (40%) Emeritus 0

Task Group: 0 Hold List: 0 Balance: Overbalanced by 1 SE *(fire suppression systems: 0 prime movers: 1 system components: 0 turbines: 2)

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Attachment No. A3

2013 FALL REVISION CYCLE *Public Input Dates may vary according to documents and schedules for Revision Cycles may change.  Please check the NFPA Website for the most up‐to‐date information on Public Input Closing Dates and schedules at 

www.nfpa.org/document# (i.e. www.nfpa.org/101) and click on the Next Edition tab. 

Process Stage 

 

Process Step  

Dates for TC 

Dates forTC with 

CC   Public Input Closing Date*  1/4/2012  1/4/2012 

  Final Date for TC First Draft Meeting  6/22/2012  3/16/2012 

Public Input  Posting of First Draft and TC Ballot  8/3/2012  4/27/2012 

Stage  Final date for Receipt of TC First Draft ballot  8/24/2012  5/18/2012 

(First Draft)  Final date for Receipt of TC First Draft ballot ‐ recirc  8/31/2012  5/25/2012 

  Posting of First Draft for CC Meeting    6/1/2012 

  Final date for CC First Draft Meeting    7/13/2012 

  Posting of First Draft and CC Ballot    8/3/2012 

  Final date for Receipt of CC First Draft ballot    8/24/2012 

  Final date for Receipt of CC First Draft ballot ‐ recirc    8/31/2012 

  Post Final First Draft for Public Comment  9/7/2012  9/7/2012 

 

  Public Comment closing date   11/16/2012  11/16/2012 

  Final Date to Publish Notice of Consent Documents (Documents that received no Comments) 

11/23/2012  11/23/2012 

  Appeal Closing Date for Consent Documents (Documents that received no Comments) 

12/8/2012  12/8/2012 

  Final date for TC Second Draft Meeting  5/3/2013  1/25/2013 

Comment  Posting of Second Draft and TC Ballot  6/14/2013  3/8/2013 

Stage    Final date for Receipt of TC Second Draft ballot  7/5/2013  3/29/2013 

(Second  Final date for receipt of TC Second Draft ballot ‐ recirc  7/12/2013  4/5/2013 

Draft)  Posting of Second Draft for CC Meeting    4/12/2013 

  Final date for CC Second Draft Meeting    5/24/2013 

  Posting of Second Draft for CC Ballot    6/14/2013 

  Final date for Receipt of CC Second Draft ballot    7/5/2013 

  Final date for Receipt of CC Second Draft ballot ‐ recirc    7/12/2013 

  Post Final Second Draft for NITMAM Review  7/19/2013  7/19/2013 

 

Tech Session  Notice of Intent to Make a Motion (NITMAM) Closing Date  8/23/2013  8/23/2013 

Preparation  Posting of Certified Amending Motions (CAMs) and Consent Documents 

10/18/2013  10/18/2013 

(& Issuance)  Appeal Closing Date for Consent Documents  11/2/2013  11/2/2013 

  SC Issuance Date for Consent Documents  11/12/2013  11/12/2013 

 

Tech Session  Association Meeting for Documents with CAMs  6/9‐12/2014  6/9‐12/2014 

 

Appeals and  Appeal Closing Date for Documents with CAMs  6/24/2014  6/24/2014 

Issuance  Council Issuance Date for Documents with CAMs  8/14/2014  8/14/2014 

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Attachment No. A4

NFPA 37 2010 Edition Tentative Interim Amendment (TIA) Submission References: 3.3 6.6.3 6.6.3.1 Submitter: Dan McMenamin, NFPA Member 1126390, a consultant on behalf of Verizon Wireless Corporation 3.3 General Definitions Communications Equipment Shelter. A small, prefabricated building, usually <500 square feet used to house communications equipment at cell, microwave or other communications sites. 6.6.3 Piping for fuel tanks other than engine-mounted tanks shall be in accordance with Chapter 27 of NFPA 30, Flammable and Combustible Liquids Code. 6.6.3.1 The fill pipe shall terminate outside the building at a point at least 600 mm (24 in.) from any building opening at the same or lower level. Exception: This provision shall not apply to fill pipes of listed secondary containment-type tanks that supply Class II liquid fuels to standby generator engines at unmanned Communications Equipment Shelters, when the filling operations are constantly attended. [NOTE: Dan, I deleted “UL” because we cannot “endorse” any one service provider.] Submitter’s Substantiation: Communications sites such as cell sites and public safety communications systems are arranged on small plots of land where a tower is a virtual ‘hotel’ for the antennas of numerous communications carriers. Often, the communications systems are housed in unoccupied industrial occupancies (precast shelter buildings) that have been delivered and installed on that site. Due to the small size of the shelter, it is not feasible to comply with these two code sections because there is no place to install a remote fuel fill that is far enough away from building openings at the same or lower level. Due to the limited space that multiple carriers share on a very small property, it is impractical to install the fuel fill any distance from the shelter. Because many cell sites are on mountain tops or other off-road areas, the relatively small trucks needed to access such locations are not equipped with Camlocks, pumps or other nozzles to achieve liquid/vapor tight connections. The shelters used for such applications already have concrete containments in the engine areas sufficient to contain spills. There is, to our knowledge, no history of fires in cell site shelters relative to diesel fuel spills. While refueling spills do occur occasionally, the existing containment and relatively small quantities involved are easily cleaned up. The majority of existing installations utilize an internal fill connection, which has worked in practice for many years.

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Attachment No. A5

Left: A 2-room shelter about to be delivered. Note that there is no place to install a fuel fill that can meet the 24” clearance requirement as is covered in 6.6.3.1. Right: a group of shelters placed in close proximity.

While no US code or other regulation requires standby engine generators at cell sites, many

telecommunications carriers provide them voluntarily. Such generators typically are in the 15KW to 60 KW size and provide power for a reliability of communications necessary to public safety and to competitive customer service.

Although many carriers use outdoor engine modules, these assemblies are not as reliable as indoor

units because weather and rodent damage problems are inherent to such units. Cell phones are how most people reach 911 services today and also are the secondary medium for

emergency responders communicating between themselves. Additionally, the primary radio systems for first responders are dependent on repeater or ‘Trunked Radio’ systems with antennas collocated on towers with cellular or other systems.

Emergency planners encourage the citizenry to prepare for evacuation emergencies with advice

similar to South Carolina’s evacuation plan: “Motorists are encouraged to have a full tank of gas when they leave, bringing food items with them and cellular phones.” Coping with disasters or weather severity is when the cellular and emergency responder systems are needed most and yet are times when commercial power is least reliable.

The standby diesel engines provided for communications sites, employ relatively small, welded steel

secondary containment type belly tanks complying with UL142 for Class II fuel oil (diesel fuel). The shelters used for such purposes are unoccupied except during periodic maintenance activities and are not considered “important buildings” as defined in NFPA 30. Further, in NFPA 76, these buildings are considered ‘redundant and replaceable”.

In sites with indoor engines, AHJs citing the International Mechanical Code (IMC) have required

carriers to provide exterior containment diesel fuel stations and remote fuel fill alarm panels. The problem is that on crowded communications sites, insufficient clearances are available to meet NFPA 37 as it is written. Today installations include both the remote fuel fill stations (mounted on the exterior wall of the shelters) and internal fill connections. In practice most fuel providers are unable to meet the requirements for camlock connections (vapor-tight connections), pumps, and associated accessories necessary to fuel the tanks from the exterior connections. So in practice the internal connections are still most commonly used to fill the tanks and the exterior fuel station going unused. Class II fuels are stable, the fuel tanks at such sites are relatively small and the telephone industry has an impeccable record for fire safety and so this initiative bears more rewards than risk.

Emergency Nature: Given the conditions indicated herein, and the contribution of standby generators to communications reliability therefore, by extension, public safety, it is vital that a Code recognized method of fueling small diesel generators for Communications Equipment shelters be established.

Proposed Tentative Interim Amendment to NFPA 37, Standard for the Installation and Use of Stationary Combustion Engines and Gas Turbines

New Subsection 9.3.3

NFPA 37-2010 Standard for the Installation and Use of Stationary Combustion Engines and Gas Turbines TIA Log No.: Reference: 9.3.3 Comment Closing Date: Submitter: Clifford C. Roberts, Chartis Global Marine and Energy Property Add a new Section 9.3.3 to read as follows: “9.3.3 The combustion gas turbine starting sequence shall include a purge cycle that will result in a nonignitible atmosphere in the turbine and its exhaust system prior to the start of the ignition sequence and the introduction of fuel.” Submitter’s Reason: The purpose of this Tentative Interim Amendment (TIA) is to reinstate an important safety provision of earlier editions of NFPA 37 that was inadvertently deleted in the processing of the current 2010 edition. This requirement appears in the prior (2006) edition of NFPA 37 as Subsection 9.3.2. Technical Validity: Proposal 37-20 (Log #CP19) in the Fall 2009 Report on Proposals (ROP) proposed a rewrite of Chapter 9 of NFPA 37. This proposal was accepted by the Technical Committee on Internal Combustion Engines and the text being proposed for reinstatement by this TIA appears in the proposal as Subsection 9.3.2. Comment 37-7 (Log #6) proposed amendments to this rewrite of Chapter 9 in the form of a new rewrite of the text beginning with Subsection 9.2.1 and extending to the end of the chapter. This comment also was accepted. Unfortunately, the text of Subsection 9.3.2 from the 2006 edition was not included in the text of the public comment and, therefore, does not appear in the text accepted therein. A poll of the Technical Committee members disclosed that it was never anyone’s intent to delete this provision and all agreed the text needs to be reinstated. This TIA reinstates the provision, numbered accordingly. Emergency Nature: Failure to properly purge the exhaust system of a gas turbine can result in a significant quantity of fuel remaining in the system. History has shown that this residual fuel can ignite explosively during turbine light off, resulting in significant damage to the system, including catastrophic rupture of the exhaust system with attendant release of projectiles that can injure persons in the area and damage other equipment in the area."

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Attachment No. A6

Proposed NFPA 37 text revision per Task Group meeting, 18 October 2012: 11.4.4.1.1* Total flooding gaseous suppression systems shall be designed to maintain the design concentration within the enclosure for a minimum of 20 minutes, or until it can be demonstrated that the engine has time sufficient to assure the fire is extinguished and engine surface temperatures have been cooled to below the autoignition temperature of combustible material present, whichever is greater. In lieu of manufacturer’s or testing lab fire data demonstrating the actual time to achieve extinguishment and cool-down, the concentration shall be maintained for a minimum of 20 minutes. A.11.4.4.1.1 Fire suppression system design concentrations and discharge durations should be held as long as the hazards of hot metal surfaces above the autoignition temperature and uncontrollable combustible liquid flow exist. The manufacturer should be consulted for applicable engine cool-down times. Testing has shown this time requirement to be approximately 20 minutes. but for many heavy duty industrial turbines it can be substantially longer. Conversely, thin walled turbines based on aircraft engines cool very quickly once fuel flow is terminated. Just as the discharge time my need to be increased for some heavy industrial turbine designs, it is appropriate to reduce the discharge duration for the aircraft engine based turbines to less than 20 minutes based on discharge tests. Information on fire testing that demonstrates the extinguishment time for a turbine design should also be considered in determining the minimum discharge time. It is recommended that the minimum discharge time be no less than twice the time demonstrated to fire extinguishment for the suppressant in use. It has been shown that the initial concentration usually will not hold for a 20-minute time period in most engine enclosures, and under these circumstances an additional extended discharge is necessary to prevent potential fire reignition due to smoldering and heat soak. Where design concentrations still cannot be maintained effectively, an alternative system should be provided 11.4.4.2* Local application gaseous agent suppression systems shall be designed to operate for a minimum of 20 minutes, or until it can be demonstrated that the engine has time sufficient to assure the fire is extinguished and engine surface temperatures have been cooled to below the autoignition temperature of combustible material present, whichever is greater. In lieu of manufacturer’s or testing lab fire data demonstrating the actual time to achieve extinguishment and cool-down, the concentration shall be maintained for a minimum of 20 minutes. A.11.4.4.2 Fire suppression system design durations should be held as long as the hazards of hot metal surfaces above the autoignition temperature and uncontrollable combustible liquid flow exist. The manufacturer should be consulted for applicable engine cool-down times. Testing has shown this time requirement to be approximately 20 minutes, but for many heavy duty industrial turbines it can be substantially longer. Conversely, thin walled turbines based on aircraft engines cool very quickly once fuel flow is terminated. Just as the discharge time my need to be increased for some heavy industrial turbine designs, it is appropriate to reduce the discharge duration for the aircraft engine based turbines to less than 20 minutes based on discharge tests. Information on fire testing that demonstrates the extinguishment time for a turbine design should also be considered in determining the minimum discharge time. It is recommended that the minimum discharge time be no less than twice the time demonstrated to fire extinguishment for the suppressant in use. An extended discharge is necessary to prevent potential fire reignition due to smoldering and heat soak. 11.4.4.3 Where retrofit of a fire suppression system is undertaken, the minimum discharge duration shall be 20 minutes unless manufacturer’s or testing lab fire data demonstrates a different discharge duration assures extinguishment and cool-down to below the autoignition temperature of combustible material present. Substantiation: The existing text clearly recognizes that the nominal 20 minute suppressant hold time may be insufficient for turbines with massive casings that will have surfaces greater than the autoignition temperature (AIT) of combustible material within the turbine enclosure. At eh other end of the spectrum is turbines developed

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Attachment No. A7

from aircraft designs where machine weight is absolutely minimized to maximize aircraft performance. Instrumented testing of the aircraft turbine derivative machines (“aeroderivative”) shows the casings and other surfaces cool very rapidly and may be below the limiting AIT in as little as three minutes. Requiring a suppressant concentration hold time of 20 minutes causes a significant and unnecessary cost impact in both equipment and suppressant storage for this class of turbine. The proposed change recognizes this difference while requiring the discipline of test data to justify the reduced time so as to assure the overall effectiveness of the installed fire suppression system. For reference, the current NFPA 850 Text

Committee Input No. 12-NFPA 37-2012 [ New Section after 5.2 ]

Revise Subsection 5.2.1 to read:

"5.2.1 Gas trains, as defined in 3.3.5, shall contain at least the following safety components:

(1) An equipment isolation valve

(2) A gas pressure regulator, if the prime mover does not operate at the gas supply pressure

(3) Two automatic safety shutoff valves (ASSVs)

(4) A manual leak test valve for each ASSV or an alternative means of proving the full closure of the ASSV

(5) A low-pressure limit control switch for engines with a 732 kW (2.5 million Btu/hr) full-load input orgreater

(6) A high-pressure limit control switch (manual reset) for engines with a 732 kW (2.5 million Btu/hr)full-load input or greater

(7) A vent valve or a valve proving system (VPS) for inlet gas pressures greater than 2 psi.

(8) A flame arrestor, when biogases are used and there is risk of having oxygen in the biogas

(9) A gas filter or strainer

(10) (7) Any other components or equipment that the manufacturer requires for safe operation"

Submitter Information Verification

Submitter Full Name: Bob Benedetti

Organization: National Fire Protection Assoc

Submittal Date: Tue Jun 26 15:21:00 EDT 2012

Committee Statement and Meeting Notes

CommitteeStatement:

The Technical Committee is considering the addition of additional safeguards to be required as partof the gas train and is asking for comment and input from user interests. The reasons for thechanges being considered follow. 5.2.1(2): The added text clarifies the type of regulator required.5.2.1(7): The added requirement for a vent valve incorporates what is already required by Subsection5.2.2. 5.2.1(8): A flame arrestor is needed as a safety device when the biogas might contain air as aresult of generation of the fuel. 5.2.1(9): A gas filter or strainer is should be provided because debrisin the gas can adversely affect proper operation of safety controls.

ResponseMessage:

Committee Notes:

Date Submitted By

Jun 28,2012

Bob Benedetti FileMaker Source: Log #4, FR-15

Public Input No. 3-NFPA 37-2012 [Section No. 5.2.1]

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bbenedetti
Text Box
Attachment No. A8

Committee Input No. 14-NFPA 37-2012 [ New Section after 5.3.1.1 ]

Revise 5.3.1.1 to read:

"5.3.1.1* The following devices shall not be required to be vented to the outside when installed inaccordance with their listing:

(1) Any regulator or zero governor that does not use atmospheric pressure to operates with gas pressureon both sides of the diaphragm

(2) A full lock-up regulator

(3) A listed regulator incorporating a with a listed vent-limiting device

(4) A regulator incorporating a dual diaphragm leak-limiting system orificed for 2.5 ft3/hr or less, based onnatural gas."

Submitter Information Verification

Submitter Full Name: Bob Benedetti

Organization: National Fire Protection Assoc

Submittal Date: Tue Jun 26 16:27:24 EDT 2012

Committee Statement and Meeting Notes

CommitteeStatement:

The Technical Committee is considering the indicated changes to 5.3.1.1 and is asking for commentand input from user interests. The reasons for the changes being considered follow. 5.3.1.1(1): Someregulators use more than one diaphragm for proper operation or for reasons of safety. As currentlyworded, item (1) does not specify to which diaphragm the gas pressure must be applied. The revisionbeing considered eliminates the overly-broad language and clarifies that 5.3.1.1 only applies to adiaphragm that does not use atmospheric pressure as a reference. 5.3.1.1(3): Technically, there is nosuch device as a "listed vent limiting device" for a gas regulator. A regulator might be listed and thelisting might include the vent limiting device as being in compliance with an applicable standard (e.g.,ANSI Z21.8), but the vent limiting device itself does not have a listing. 5.3.1.1(4): There exists anothertechnology that limits the escape of gas into the ambient space due to rupture. This technology uses adouble diaphragm leak limiting system located under the regulator dome. The extra diaphragm, aso-called safety diaphragm, is only called upon to operate in the rare case that the atmosphericdiaphragm fails. If that occurs, the ‘safety diaphragm’ conforms perfectly to and seals to the upperdome of the regulator, forcing gas to escape out an internal vent limiting device at a leakage rate thatis significantly less than 2.5 ft3/hr. Another safety feature of this design is that it can prevent significanthigh gas conditions from occurring downstream, because the safety diaphragm can take over andprevent some high gas conditions if the atmospheric diaphragm fails. This leak limiting system hasbeen used in the USA since the early 1990’s and has been accepted by many authorities within theUS and Canada (e.g. CSA B149.1 and the State Board of MA).

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bbenedetti
Text Box
Attachment No. A9

Committee Input No. 13-NFPA 37-2012 [ New Section after 5.2.2 ]

Revise 5.2.2 to read:

"5.2.2 For engines operating at more than a gauge pressure of 14 kPa (2 psi) inlet gas pressure to theequipment isolation valve, either a vent valve shall be provided between the two ASSVs or a listed valveproving system (VPS) shall be installed to prove the two ASSVs upon each startup or after each shutdown. This vent valve shall fail open without an externally supplied source of power and shall discharge outdoors."

Submitter Information Verification

Submitter Full Name: Bob Benedetti

Organization: National Fire Protection Assoc

Submittal Date: Tue Jun 26 16:21:00 EDT 2012

Committee Statement and Meeting Notes

CommitteeStatement:

The Technical Committee is considering the identified changes to 5.2.2 and seeks input from userinterests. The amendment allows the use of a valve proving system (VPS) as an alternative to a ventvalve. The VPS has been used in the USA on gas fired equipment since the early 1990’s in many gasfired industrial applications, automotive applications, and larger boilers and is referenced in othercodes and standards such as NFPA 85, NFPA 86, and CSA B149.3. A VPS essentially performs avalve seat integrity test on each ASSV. As a result, there is no risk of venting gas into the atmosphereif the upstream ASSV either fails to close or leaks and the integrity of both ASSV’s are checkedduring each valve proving sequence. The amendment also clarifies the correct pressure reference forthe vent valve requirement.

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bbenedetti
Text Box
Attachment No. A10

Committee Input No. 4-NFPA 37-2012 [ New Section after 1.3.2 ]

Add new Subsection 1.3.3 to read:

1.3.3 This standard applies to temporary equipment that is being placed in a hazardous area or beingused for pumping of hazardous fluids other than their own fuel for any duration.

Renumber existing 1.3.3 to 1.3.4.

Submitter Information Verification

Submitter Full Name: Bob Benedetti

Organization: [ Not Specified ]

Submittal Date: Fri Jun 15 14:06:28 EDT 2012

Committee Statement and Meeting Notes

CommitteeStatement:

If CI-3 is adopted in the Second Draft stage, then this proposed new 1.3.3 should also beadopted to correlate the application section of NFPA 37 with the new 4.4.1.1. A Task Group hasbeen appointed to consider this.

ResponseMessage:

Committee Notes:

Date Submitted By

Jun 28,2012

Bob Benedetti FileMaker Source: Log #2, CI-4

Public Input No. 20-NFPA 37-2012 [Section No. 1.3.1]

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bbenedetti
Text Box
Attachment No. A11

Committee Input No. 3-NFPA 37-2012 [ New Section after 4.4.1 ]

Proposed new paragraph 4.4.1.1.

If a temporary engine driven unit compressing a flammable gas or pumping a flammable liquid is placed inarea that is not having a similar hazard than the area where the unit is placed must be declared hazardousbased on the pumped flammable gas or liquid according to the NFPA 70 and comply with NFPA 70 and thisstandard in that area. If the area of placement for temporary equipment is already a hazardous area thenthe temporary unit must comply with the hazardous area where it is placed in addition to the area createdby compressing flammable gas or pumping flammable liquid as stated above.

Submitter Information Verification

Submitter Full Name: Bob Benedetti

Organization: [ Not Specified ]

Submittal Date: Fri Jun 15 13:51:23 EDT 2012

Committee Statement and Meeting Notes

CommitteeStatement:

The Technical Committee is reluctant to adopt the porposed concept without additional input andhas formed a task Group to study the issue. The Technical Committee solicits input from the publicand invites the submitter of the original Public Input to participate.

ResponseMessage:

Committee Notes:

Date Submitted By

Jun 28,2012

Bob Benedetti FileMaker Source: Log #2, CI-5

Public Input No. 22-NFPA 37-2012 [Section No. 4.4.1]

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Public Comment No. 5-NFPA 37-2012 [ Section No. 2.3.4 ]

2.3.4 UL Publications.

Underwriters Laboratories Inc., 333 Pfingsten Road, Northbrook, IL 60062-2096.

ANSI/UL 900, Standard for Air Filter Units, 2004 , with revisions through November 2009 2012 .

Statement of Problem and Substantiation for Public Comment

Update referenced standard to most recent edition as indicated.

Submitter Information Verification

Submitter Full Name: John Bender

Organization: UL LLC

Submittal Date: Wed Oct 24 13:05:03 EDT 2012

Copyright Assignment

I, John Bender, hereby irrevocably grant and assign to the National Fire Protection Association (NFPA) all and full rights in copyright in thisPublic Comment (including both the Proposed Change and the Statement of Problem and Substantiation). I understand and intend that Iacquire no rights, including rights as a joint author, in any publication of the NFPA in which this Public Comment in this or another similar orderivative form is used. I hereby warrant that I am the author of this Public Comment and that I have full power and authority to enter intothis copyright assignment.

By checking this box I affirm that I am John Bender, and I agree to be legally bound by the above Copyright Assignment and the termsand conditions contained therein. I understand and intend that, by checking this box, I am creating an electronic signature that will, upon mysubmission of this form, have the same legal force and effect as a handwritten signature

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bbenedetti
Text Box
Attachment No. A12

Public Comment No. 7-NFPA 37-2012 [ Section No. 4.1.4 ]

4.1.4 Engines Located Outdoors.

Engines and their weatherproof housings if provided, that are installed outdoors shall be located atleast 1.5 m (5 ft) from openings in walls and at least 1.5 m (5 ft) from structures having combustiblewalls. A minimum separation shall not be required where either of the following conditions exist:

(1) All walls of the structure that are closer than 1.5 m (5 ft) from the engine enclosure have a fireresistance rating of at least 1 hour.

(2)

4.1.4.1 * The full scale fire tests shall be conducted in the vicinity of combustible walls constructedof materials with a level of combustibility not less than that of the materials intended to be presentwhere the engine is to be located.

4.1.4.2 The full scale fire tests shall result in complete consumption of all combustible materialscontained within the engine.

4.1.4.3 The full scale fire tests shall represent fire scenarios where the engine is operating andwhere it is not operating.

4.1.4.4 * Engines located outdoors shall be placed at a separation distance from the nearestcombustible wall that is greater than the distance at which the fire tests have been conducted, toprovide a margin of safety.

A.4.1.4.1 Combustible materials exhibit different levels of combustibility or of ignitability. Examplesof combustible exterior wall materials include various types of siding, such as vinyl, wood andpolypropylene, as well as different exterior wall coverings (such as particleboard), exterior insulationand finish systems and decorative laminates. It has been shown that these diverse combustiblematerials can have very different levels of fire performance or of ignitability (see for example, NFPA555). Therefore, the full scale fire tests should be conducted in the presence of combustiblematerials that adequately represent the potential fire hazard to be expected where the engine is tobe placed.

A.4.1.4.4 If fire testing has demonstrated, for example, that a fire within the engine does not causeignition of combustible walls at a certain separation distance it is important that the engine be placedat a separation distance greater than that at which the tests have been conducted. A reasonablemargin of safety (for example 50%) should be provided to deal with the potential variability of the firetests.

A.4.1.4(2) Calculation procedures, such as those given in NFPA 555, Guide on Methods forEvaluating Potential for Room Flashover, are useful tools to assess the probability of safe engineplacement.

Additional Proposed Changes

File Name Description Approved

CommentNFPA_37Marcelo_Hirschler4_1_4.docxProposed Change to 4.1.4 and Substantiation.

CommentNFPA37Testing_of_generators_Fire_Mats_2011.pdf Supporting material

Statement of Problem and Substantiation for Public Comment

This section lacks the information an authority having jurisdiction needs to assess any reports provided by an engine manufacturer seeking to place engines close to combustible walls. There are no criteria for how to demonstrate that an engine fire will not ignite a combustible wall or for how close to the wall the engine can be placed. The proposed language provides that information without being a detailed test protocol and without ruling out the use of calculations as a tool.

* The weatherproof enclosure is constructed of noncombustible materials and it has beendemonstrated that a fire within the enclosure will not ignite combustible materials outside theenclosure. Calculations or full scale tests, acceptable to the authority having jurisdiction,using the engine and its weatherproof housing, based on the criteria in 4.1.4.1 through4.1.4.4, have demonstrated that a fire within the enclosure will not ignite combustiblematerials outside the enclosure.

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1. In view of the close proximity between homes that often install engines or generators to ensure uninterrupted electrical supply, clear criteria for engine placement are essential to permit adequate enforcement. NFPA 37 does not contain enforceable criteria. 2. This comment incorporates the wishes of the technical committee that NFPA 37 should not specify details of the full scale fire test procedure to be used for determining acceptable separation distances. This is reflected in the revised wording.3. This comment also accepts the wishes of the technical committee that calculation methods be retained as an option. This is reflected in the revised wording.4. This comment does not propose wording that would require specific test protocols but simply proposes wording that ensures a minimal level of safety, after the calculations or full scale fire tests have been conducted.5. This comment suggests the addition of the phrase “acceptable to the authority having jurisdiction” because that will ensure an “approved” level of safety. 6. If an engine burns it can cause the ignition of nearby combustible walls. Whether ignition of combustible walls occurs will depend primarily on three factors: (a) the amount and fire performance of the combustible materials in the engine and the engineering design of the engine and its enclosure, (b) the materials contained in the combustible walls present and (c) the distance between the engine and the combustible walls.7. Fire tests have demonstrated that fire tests with some engines can be more severe when the generator/engine is not operating because the associated cooling fan in the generator/engine can result in the extinguishment of the fire when the generator/engine is operating but not when the generator/engine is idle. This has been shown for at least two engine designs. (a) Jason Huczek (Southwest Research Institute) [“Custom Fire Testing of Power Generators for NFPA 37 Compliance”, at the NFPA 2010 Annual Meeting, Session T68, June 9, 2010] and (b) Marcelo Hirschler [“Testing of Residential Electrical Generators”, Fire and Materials Conf., San Francisco, CA, Jan. 31-Feb. 2, 2011, pp. 71-81, Interscience Communications, London, UK, attached].8. There can be no assurance that every generator/engine will be provided with an adequate fan. Therefore, full scale fire tests or calculations need to be conducted with both the engine operating and the engine idle.9. The full scale fire tests or calculations leading to the determination of the safe location distance need to be conducted in such a way that there is complete consumption of the combustible materials in the engine/enclosure to ensure that the full scale fire tests or calculations actually address the fire hazard. 10. If the full scale fire tests or calculations do not result in complete consumption of the combustible materials in the engine there can be no assurance that the results are fully representative of the actual fire hazard.11. There are different types of combustible wall materials that are in common use and the full scale fire tests need to be conducted using either the wall materials to be used in the actual installation or the combustible wall materials with the poorest fire performance. Fire tests have demonstrated that polypropylene siding is a more combustible wall material than either wood siding or vinyl (PVC) siding. Peak heat release rate data for polypropylene, wood and PVC siding materials are shown below.12. The distance between the engine and the combustible walls must provide be a reasonable margin of safety so that if the tests are conducted at a distance of, for example 1 ft., the engine enclosure should not be permitted to be placed closer than 1.5 ft. (i.e. a 50% margin of safety).13. This comment proposes the elimination of the requirement that the weatherproof enclosure be constructed of noncombustible materials because that is not an enforceable requirement and has long been ignored by manufacturers. For the vast majority of engines the weatherproof enclosures contain some combustible components (such as knobs, for example) and their presence or absence is of no consequence if a fire that destroys all combustible materials does not cause wall ignition, and that is the key issue.

Heat release rate of siding materials (calorimeter testing)Vinyl (PVC) siding: 187 kW/m2Cedar siding: 309 kW/m2Polypropylene siding: 546 kW/m2

A publication by Marcelo Hirschler that provided one example of a set of tests that could be used to analyze the safe placement of generators follows (figures have been omitted)

TESTING OF RESIDENTIAL ELECTRICAL GENERATORS

Marcelo M. HirschlerGBH International, US

ABSTRACT

It is becoming increasingly common to find electrical generators used to ensure continuity of residential electrical service. Such electrical generators are usually placed as far away as possible from the combustible walls of homes. However, homeowners want to maximize the use of their yards/gardens/patios and prefer to

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minimize such separations.

NFPA 37 requires that generators be placed at least 1.5 m from combustible walls unless tests have demonstrated that a fire within the generator enclosure will not ignite combustible materials outside the enclosure, while US codes require only a separation of 1.5 m between walls of residences.

In this project a series of fire scenarios were identified which would represent the most extreme conditions under which a generator would have the potential to cause ignition of nearby combustible siding. The generator, containing an internal combustion gas-fueled engine, was placed within an open alcove-like enclosure consisting of three “walls” lined with non fire retarded polypropylene, simulating polypropylene siding. The walls were placed at a distance of 0.3 m from the generator.

Tests were conducted with generators fed by natural gas and with ones fed by propane. Temperatures were measured on the walls, inside the generator and on the open side of the alcove, via thermocouples. Heat fluxes were assessed on the walls and open side. Heat and smoke release was also assessed.

In none of the tests did ignition of polypropylene on the walls occur. In order to allow for a reasonable safety margin, it was concluded that the electrical generators tested were suitable for installation within 0.45 m of combustible walls. The most severe scenario has been shown to be when the engine and fan stop after running for a while and then ignition occurs and all combustibles can burn, to a degree that is a function of their fire performance.

INTRODUCTION

In recent years the use of generators for residences has become common due to the interest by homeowners to ensure uninterrupted power supply. Such generators are normally placed outside residences and connected so that they provide home electricity within moments of a power outage.

NFPA has had a standard for installation and use of combustion engines since the early 1900s and, in 2010, issued the latest edition of NFPA 37, Standard for the Installation and Use of Stationary Combustion Engines and Gas Turbines [1]. This document contains the following requirement:

“4.1.4 Engines Located Outdoors. 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 structures having combustible walls. A minimum separation shall not be required where the following conditions exist: (1) The adjacent wall of the structure has a fire resistance rating of at least 1 hour.(2)* The weatherproof enclosure is constructed of noncombustible materials and it has been demonstrated that a fire within the enclosure will not ignite combustible materials outside the enclosure.”

Associated annex commentary: “A.4.1.4 (2) Means of demonstrating compliance are by means of full-scale fire tests or by calculation procedures, such as those given in NFPA 555, Guide on Methods for Evaluating Potential for Room Flashover [2].”

A requirement that stationary generators be maintained in accordance with NFPA 37 is included in the Uniform Fire Code (NFPA 1[3]). Another requirement that permanently installed equipment powered by internal combustion engines be installed in accordance with NFPA 37 is included in the International Fuel Gas Code (IFGC [4[), which is, in turn, referenced by the International Fire Code [5].

It is very unusual in the USA for residential exterior walls to exhibit fire resistance ratings of 1 hour, since residences tend to have “combustible construction”. Moreover, homes are often very close to each other, so that a 1.5 m separation from both the home associated with the generator and the neighboring home constitutes a burden for the homeowner, who may not be able to install generators. However, the vague language results in generators being normally installed with separation distances of at least 1.5 m from homes. The fire safety will be a function of generator design and of the related materials of construction.

EXPERIMENTAL

Small scale material tests, using the cone calorimeter, ASTM E 1354 [6], are an excellent way of choosing materials that have low heat release and good fire performance. One goal is to try to minimize the use of materials that exceed the International Fire Code requirement for large waste containers placed within 1.5 m of combustible walls: that the materials exhibit a peak heat release rate not exceeding 300 kW/m², when tested at an initial test heat flux of 50 kW/m², in the horizontal orientation. However, even for materials that comply with this goal, it is still necessary to ensure that fires will not ignite the wall.

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In one project, conducted at the Department of Fire Technology of the Southwest Research Institute, full scale tests were conducted to assess the potential for a fire originating inside a generator to ignite nearby combustible walls. The siding material with the poorest fire performance in use in the USA is polypropylene (PP) siding. Each test scenario involved a generator inside a three wall corner. The walls were of lumber and gypsum wallboard construction covered with sheets of thin non FR PP sheets, simulating the siding. Each wall was 2.44 m (8 ft) high and 1.83 m (6 ft) long. The walls were placed 0.3 m (1 ft) from the generator. The entire assembly was set up directly under a 3 x 3 m (10 × 10 ft) calorimetry exhaust hood. During testing, the generator was placed under load by connecting it to a load bank, able to provide a 30 kW load. The generator exhaust was positioned such that the exhaust pointed towards the open side, in accordance with all manufacturers’ installation instructions.

Generators have safety features that turn the engine off if a gas leak occurs; the maximum gas leak that allows generator operation without it turning off was used, so that the worst case scenario was considered.

Instrumentation included 20 thermocouples, 4 placed inside the generator and 4 placed outside on each of the three walls and 4 on the open side. Additionally a heat flux gauge was placed facing the center of each generator side. Heat and smoke release from the tests were measured in the duct connected to the exhaust hood, with heat release by oxygen consumption calorimetry and smoke released with a white light source/detector, using the techniques described in ASTM E 2067 [7], commonly used for large scale tests.

Figure 1: Position of heat flux gauges and thermocouples on generator and polypropylene walls

TESTS AND RESULTS

A significant amount of summary data from all tests can be found in Table 1. All the generators used were gas-fed residential standby generators with two compartments: one for the engine and one for controls. The generators weighed 245 kg (540 lb), of which 13.7 kg (30.3 lb) were combustible materials.

Test 1 - A natural gas generator was run continuously under high external load (50 A). The generator turned itself off after just over 34 minutes, due to overheating of the oil temperature (in view of the excessive load imposed), without any ignition occurring in the engine or on the wall. Temperatures and heat fluxes remained fairly steady and not unusually high. The peak heat release rate measured was 55 kW and the total smoke released was 16 m².

Test 2 – Unplanned test, where the natural gas generator was run while monitoring the oil temperature to determine the maximum external load that will not cause the generator to overheat and turn itself off. A thermocouple was installed on the oil dip stick, to monitor the oil temperature, in order to establish a suitable external load, that at steady state, would not cause the engine oil to reach a temperature that would activate the engine overheat feature, which shuts down the engine. The external load established was 19 A, and this load was used for the other tests. No ignition occurred in the engine or on the wall. Temperature and heat flux data were unremarkable. Heat and smoke release was not measured.Test 9 – This test was intended as a repeat of test 1, but with a propane generator. A propane generator was monitored while running for 45 min with a 19 A external load. After 45 min various trials were conducted increasing and decreasing the electrical load which caused the engine to start and stop. The test was terminated at 52 min.

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No ignition of any kind occurred. Temperature and heat flux data were unremarkable. The peak heat release rate measured was 32 kW and the total smoke released was 2 m². Test 3 – A natural gas generator was run under an external load of 19 A; natural gas was allowed to leak into the generator control compartment by diverting the gas line within the compartment, as close to the generator floor as practicable. The gas leak was the maximum gas leak (15 ft³/h; 1.2 x 10-4 m³/s) which would not activate the generator safety feature. After 3 min of the generator running with the gas leak, electric matches, which had been placed near the leak, were activated externally to attempt ignition. The test was continued until all temperatures and heat fluxes were steady state. The test was terminated at 15.5 min. No ignition occurred inside the engine or on the wall. Temperature and heat flux data were unremarkable. The peak heat release rate measured was 27 kW and the total smoke released was 3 m².

Test 5 – This test was intended to simulate the accidental presence of external combustibles (such as leaves, branches, the unit manual and its associated bag, or others) which could have fallen inside the unit within the control compartment near the battery (which has a plastic casing). This was done by placing a plastic bag (with 40 sheets of standard white printer paper [8.5 x 11 in.; 216 x 279 mm] inside) on top of the battery casing, near the unit floor, inside the control compartment. The combustibles were ignited externally with an electric match. A natural gas generator was kept running for 15 min with a 19 A external load. After 15 min, an external natural gas leak source was directed into the control compartment, flowing once more at 15 ft³/h (1.2 x 10-4 m³/s). The gas leak was directed just above the battery, which is where the plastic bag had been placed The gas was ignited using electric matches and allowed to continue burning for 10 s. The generator was left on and under load for the entire test. Ignition of the gas occurred, which provided an ignition source for the plastic bag and paper sheets. The data was monitored for 23 min to ensure steady state. Upon completion of the test, the plastic bag and paper sheets had suffered slight discoloration and charring in the area of flame impingement. No damage to the interior of the generator was observed. Temperature and heat flux data were unremarkable. The peak heat release rate measured was 33 kW and the total smoke released was 1 m².

Test 6 - This test, like test 5, was intended to simulate the accidental presence of external combustibles (such as leaves, branches, the unit manual and its associated bag, or others) which could have fallen inside the unit or an electrical fault within the engine compartment near the electrical equipment and wiring. This was done by placing an identical plastic bag to the one used in test 5, also with 40 sheets of paper inside, by the electrical equipment near the unit floor, inside the engine compartment. A natural gas generator was kept running for 15 min with a 19 A external load. After 15 min, an external natural gas leak source was directed into the engine compartment, flowing once more at 15 ft³/h (1.2 x 10-4 m³/s). The gas leak was directed near the electrical equipment, which is where the plastic bag had been placed The gas was ignited using electric matches and allowed to continue burning for 10 s. The generator was left on and under load for the entire test. Ignition of the gas occurred, which provided an ignition source for the plastic bag and paper sheets. The data was monitored for 35 min to ensure steady state. Upon completion of the test, the plastic bag and paper sheets had been completely consumed and only ashes remained. Minimal discoloration but no significant burning was observed in the interior of the generator. Temperature and heat flux data were unremarkable. The peak heat release rate measured was 32 kW and the total smoke released was 30 m².

Test 7 – This test was intended as a repeat of test 5, but with a propane generator. In view of the much longer extension of a propane flame compared to a natural gas flame, the gas flow rate was set at 2.5 ft³/h (2.0 x 10-5 m³/s).The combustibles were ignited externally with an electric match. A propane generator was kept running for 15 min with a 19 A external load. After 15 min, an external propane leak source was directed into the control compartment, flowing at 2.5 ft³/h (2.0 x 10-5 m³/s). The gas leak was directed just above the battery, which is where the plastic bag had been placed The gas was ignited using electric matches and allowed to continue burning for 10 s. The generator was left on and under load for the entire test. Ignition of the gas occurred, which provided an ignition source for the plastic bag and paper sheets. The data was monitored for 22 min to ensure steady state. Upon completion of the test, the plastic bag and paper sheets had suffered slight discoloration and charring in the area of flame impingement. No damage to the interior of the generator was observed. Temperature and heat flux data were unremarkable. The peak heat release rate measured was 32 kW and the total smoke released was 10 m².

Test 8 – This test was intended as a repeat of test 6, but with a propane generator. Again, the propane gas flow rate was set at 2.5 ft³/h (2.0 x 10-5 m³/s).The combustibles were ignited externally with an electric match. An identical plastic bag to the one used in other tests, also with 40 sheets of paper inside, was placed by the electrical equipment near the unit floor, inside the engine compartment. A propane generator was kept running for 15 min with a 19 A external load. After 15 min, an external propane leak source was directed into the engine compartment, flowing at 2.5 ft³/h (2.0 x 10-5 m³/s). The gas leak was directed near the electrical equipment, which is where the plastic bag had been placed The gas was ignited using electric matches and allowed to continue burning for 10 s. The generator was left on and under load for the entire test. Ignition of the gas occurred, which provided an ignition source for the plastic bag and paper sheets. The data was monitored for 20 min to ensure steady state. Upon completion of the test, the plastic bag and paper sheets had been completely consumed and

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only ashes remained. Minimal discoloration but no significant burning was observed in the interior of the generator. Temperature and heat flux data were unremarkable. The peak heat release rate measured was 29 kW and the total smoke released was 1 m².

Table 1 - Summary DataTest # Units 1 2 3 4 5 6 7 8 9 10Pk HRR kW/m2 55 ND 27 129 33 32 32 29 32 19time to Pk HRR s 153 ND 250 1,885 359 1,461 1,049 462 460 565THR MJ 89 ND 7 174 25 39 29 26 61 11Pk OD 1/m 0.01 0.01 0.00 1.01 0.00 0.02 0.00 0.00 0.00 0.03Time Pk OD s 2,337 450 0 1,957 84 1,379 1,547 268 190 2,375Pk SRR m2/s0.02 0.03 0.00 5.26 0.01 0.09 0.02 0.01 0.01 0.10Time Pk SRR s 2,337 450 0 1,957 84 1,379 1,547 268 190 2,375TSR m2 16 15 0 3,658 1 30 10 1 2 74Pk Ht Flux Rear Wall kW/m2 0.2 0.2 0.1 20.5 * 0.0 0.2 0.1 0.1 0.1 0.2Pk Ht Flux Left Wall kW/m2 0.4 0.4 0.1 1.9 0.3 0.3 0.2 0.2 0.3 0.2Pk Ht Flux Right Wall kW/m2 0.4 0.4 0.0 3.6 0.2 0.2 0.2 0.2 0.2 0.2Pk Ht Flux Front kW/m2 4.8 2.1 1.1 1.9 1.7 1.9 1.5 1.5 1.5 1.0Pk Temp Rear Wall ºC 36 37 26 266 36 37 34 35 36 35Pk Temp Left Wall ºC 35 33 25 84 35 37 34 36 38 34Pk Temp Right Wall ºC 44 34 24 82 36 36 34 36 36 32Pk Temp Front ºC 129 72 56 58 65 68 63 58 64 52Pk Temp Generator ºC 147 106 98 896 585 207 463 171 120 181

Test 4 - This test was started off as a replicate of test 3 (with the same gas leak, load and ignition source), but with the exception that it involved turning off the generator engine after 15 min of operation. The gas was then ignited, with the engine not running, with an external electric match, and allowed to continue burning until 34 min 50 s into the test. Ignition occurred within the engine and the fire was allowed to continue burning until the fire stopped. Enough heat was emitted to cause melting of the polypropylene sheet and some burning on the floor. However no ignition of the polypropylene sheet occurred and the test was terminated at 55 min, when the fire was virtually extinguished naturally. The peak heat release rate measured was 129 kW, the total heat released was 137 MJ, the total smoke released was 3,700 m² and the peak smoke release rate was 5.3m²/s. This was by far the most severe fire test conducted, as a consequence of turning off the engine and its fan, and yet it did not result in wall ignition.

Test 10 – This test was intended as a repeat of test 4, but with a propane generator. In other words this was intended to be the most severe test with the propane generator because the engine was turned off after 15 min. Again, the propane gas flow rate was set at 2.5 ft³/h (2.0 x 10-5 m³/s).The gas was ignited externally with an external electric match, with the engine not running, and allowed to continue burning for 55 min. Ignition occurred within the engine and the fire was allowed to continue burning until the test was terminated. Due to measurement of minimal temperatures within the generator, the gas flow was increased to 4.0 ft³/h (3.2 x 10-5 m³/s) air at 33 min and 30 s and to 6.0 ft³/h (4.7 x 10-5 m³/s) at 39 min. During this time, the gas supply to the generator was also left on. The heat generated by the gas flame was sufficient to cause melting of the plastic components within the generator but did not cause any steady ignition of generator combustibles and did not cause any ignition or melting of the polypropylene sheet walls. There was no burning on the floor. The test was terminated at 55 min. The peak heat release rate measured was 19 kW, the total heat released was 10 MJ, the total smoke released was 75 m² and the peak smoke release rate was 0.1m²/s. In spite of the higher severity of this test, as a consequence of turning off the engine and its fan, and yet it did not result in wall ignition. DISCUSSION

Figures 2-4, shown above, contained heat release rate data for all tests where this was measured, divided into three groups: Tests 1 and 9, normal operation of the generator with high load, are in Figure 2. Tests 3, 5, 6, 7 and 8, where various ignition sources were used, with the generator (and its fan) running, are in Figure 3, showing very low heat release rates. Tests 4 and 10, where the generator (and its fan) was stopped before ignition, are in Figure 4.

In all tests the highest temperatures were measured inside the generator (see Table 1) and the second highest temperatures (and the highest heat fluxes) were measured at the “front”, meaning the side of the generator where the exhaust was pointing, which was not pointing to a wall. Generator manufacturer manuals (and legitimate installers) will always instruct the users to direct the engine exhaust away from any combustibles. With the exception of the test in which all the generator combustibles burnt, none of the heat flux levels to any wall reached

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0.5 kW/m² and none of the temperatures exceeded 45ºC. In the test with excessively high loading (and where the engine stopped running) temperatures on the front (the exhaust side) reached 129ºC. Even in test 4 the back wall temperatures did not exceed 266ºC, which is not enough to ignite either wood or plastic siding.

Figures 5 and 6 show the heat flux and temperature on the back wall for test 4 and the other temperatures for the same test. The temperatures at all walls were not high enough to cause ignition of any wall material. On the other hand it is possible that the heat flux levels at the back wall could have been high enough for ignition if they had been more uniformly distributed. The measurement location was very close to the place where the flames came out of the generator and reflected a localized heat flux only.

It is of interest to note that another project was conducted to investigate the flammability of residential electrical generators [7]. The objective of that project was to determine the worst case ignition/fire scenario for certain specific generators and to experimentally measure the ignitability of items outside the engine enclosure at various distances from the enclosure. Ignition sources were placed inside the generator enclosure and temperatures and heat fluxes were measured at distances ranging from 0.3 m (1 ft) to 0.9 m (3 ft) from the enclosure. No gas leaks or external ignition sources were used and no walls were placed in the vicinity of the generators. However, the tests did not lead to high heat fluxes or temperatures and the most severe scenario was found to be the case where the engine was not operating.

The generators tested in this project contained a minimal amount of combustibles, as stated above (less than 15 kg). Moreover, cone calorimeter tests had been used in advance to eliminate, or at least limit, both the amount of combustibles and their heat release rate. The average effective heat of combustion of the materials used in this generator was ca. 12.7 MJ/kg (as calculated from the total heat released in test 4 and the total mass of combustibles contained in the generator). In particular, the generators were placed on a pad (which is more or less an integral part of the generator unit) that is noncombustible. That represents a contrast with many other generators that are placed on polyolefin pads, which exhibit high heat release rates. The average effective heat of combustion of plastic materials can be as high as 50 MJ/kg and polyolefins tend to be on the high end of this range (often > 40 MJ/kg). This is an important consideration when investigating the safety of residential generators.

CONCLUSIONS

The following conclusions can be drawn from this work:

1. Electrical generators are capable of causing a significant fire, if most of the combustibles associated with them burn.2. Electrical generators usually include cooling fans, which are able to move enough air through the generator that many small ignition sources are extinguished before they become large fires. The generators investigated contained such cooling fans.3. If a small, internal or external, ignition source causes a fire within an electrical generator, while it is operating, there is a significant likelihood that the fire will not grow very large, due to the safety features normally included, especially the cooling fan. 4. The most severe fire situation for an electrical generator is one in which the generator engine is operating for some time and then stops and an ignition source, external or internal, soon afterwards, with the engine hot, starts a fire inside the generator.5. The scenario in which the generators investigated in this work were placed represented an extremely severe fire scenario, for the following reasons: (1) non fire retarded polypropylene is the commercial siding material with the poorest fire performance in use, significantly less safe than poly(vinyl chloride) (PVC, vinyl) or wood; (2) the use of an alcove with three walls minimized the possibility of air currents cooling the generator once a fire has been established and (3) the use of high walls on three sides (significantly higher than the generator itself) ensured that cooling air currents were also not available from above the generator.6. With the generators investigated in this study, ignition sources representing small amounts of external combustibles were unable to cause any significant fire outside the generator.7. With the generators investigated in this study, ignition sources representing gas leaks inside the generator were unable to cause any significant fire outside the generator as long as the generator was operating.8. With the generators investigated in this study, a small gas leak inside the generator was able to cause a fire large enough to burn all the combustibles present. However, this occurred only in one of the two tests conducted with that scenario.9. With the generators investigated in this study, even when all the combustible materials burnt there was no ignition of the polypropylene wall material located 0.3 m from the generator.

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10. With the generators investigated in this study, none of the fire scenarios studied resulted in ignition of the polypropylene wall material.11. The generators investigated in this study can safely be used at a separation distance from a combustible wall much smaller than the 1.5 m that is required by NFPA 37. In fact, a separation distance of not less than 0.45 m from any one combustible wall would be reasonably safe for the generators investigated. The difference between the separation distance used in the studies (where other worst case conditions were used) and the recommended safe distance from a combustible wall is a reasonable safety margin.12. It is clear that the above conclusion is heavily dependent on two factors: (1) the fire performance of any combustible materials contained within the generator, and its pad, and (2) the design of the generator.13. No standardized test method exists for assessing whether a particular residential generator is able to be used safely at distances of less than 1.5 m. Such a standardized test needs to be developed.14. The use of some combustible materials is necessary for an electrical generator. Therefore such materials must exhibit high fire performance, for example low heat release rate as assessed by a cone calorimeter.

ACKNOWLEDGEMENTS

The author is grateful for the help provided by Anthony Sauceda and David Ewan, of the Department of Fire Technology at the Southwest Research Institute, in San Antonio, TX, where the fire tests were conducted.

REFERENCES

1. NFPA 37, Standard for the Installation and Use of Stationary Combustion Engines and Gas Turbines, National Fire Protection Association, Quincy, MA.2. NFPA 555, Guide on Methods for Evaluating Potential for Room Flashover, National Fire Protection Association, Quincy, MA.3. UFC, Uniform Fire Code, NFPA 1, National Fire Protection Association, Quincy, MA.4. IFGC, International Fuel Gas Code, International Code Council, Washington, DC.5. IFC, International Fire Code, International Code Council, Washington, DC.6. ASTM E 1354, Standard Test Method for Heat and Visible Smoke Release Rates for Materials and Products Using an Oxygen Consumption Calorimeter, American Society for Testing and Materials, West Conshohocken, PA.7. Huczek, J.P., “Custom Fire Testing of Power Generators for NFPA 37 Compliance”, NFPA World Safety Conference & Exposition, Las Vegas, NV, June 7-10, 2010.

Related Public Comments for This Document

Related Comment Relationship

Public Comment No. 8-NFPA 37-2012 [Section No. A.4.1.4(2)]

Related Items from the Public Input Stage for This Document

Related Item

FR16

Public Input No. 1-NFPA 37-2012 [Section No. 4.1.4]

Public Input No. 2-NFPA 37-2012 [Section No. A.4.1.4(2)]

Submitter Information Verification

Submitter Full Name: Marcelo Hirschler

Organization: GBH International

Submittal Date: Sun Nov 04 23:13:37 EST 2012

Copyright Assignment

I, Marcelo Hirschler, hereby irrevocably grant and assign to the National Fire Protection Association (NFPA) all and full rights in copyright inthis Public Comment (including both the Proposed Change and the Statement of Problem and Substantiation). I understand and intend thatI acquire no rights, including rights as a joint author, in any publication of the NFPA in which this Public Comment in this or another similaror derivative form is used. I hereby warrant that I am the author of this Public Comment and that I have full power and authority to enter intothis copyright assignment.

By checking this box I affirm that I am Marcelo Hirschler, and I agree to be legally bound by the above Copyright Assignment and theterms and conditions contained therein. I understand and intend that, by checking this box, I am creating an electronic signature that will,upon my submission of this form, have the same legal force and effect as a handwritten signature

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Public Comment No. 13-NFPA 37-2012 [ Section No. 5.2.1 ]

5.2.1

Gas trains, as defined in 3.3.5, shall contain at least the following safety components:

(1) An equipment isolation valve

(2) A gas pressure regulator, if the prime mover does not operate at the gas supply pressure

(3) Two ASSVs automatic safety shutoff valves (ASSV)

(4) A manual leak test valve for each ASSV or an alternative means of proving the full closure ofthe ASSV

(5)

(6)

(7) A vent valve or a valve proving system (VPS) for inlet gas pressures greater than 2 psi

(8) A flame arrestor, when biogases are used and there is risk of having oxygen in the biogas

(9) A gas filter or strainer

(10) Any other components or equipment that the manufacturer requires for safe operation

(11) Overpressure protection shall be provided in either whent the supply pressure exceeds thepressure rating of any downstream component or when the failure of single upstream, lineregulator or service pressure regulator results in a supply pressure exceeding the pressurerating of any downstream component. The overpressure protection shall be provided by anyone of the following:

• Series regulator in combination with a line regulator or service pressure regulator,

• Monitoring regulator installed in combination with a line regulator or service pressure regulator,

• Full capacity pressure relief valve, or a

• Overpressure cutoff device, such as slam-shut valve or a high pressure switch in combination withadequately rated shuoff valve.

Statement of Problem and Substantiation for Public Comment

Overpressure protection devices are other safety devices needed on the gas train in cases when devices on the gas train are rated for the supply pressure if there is a failure of the upstream supply pressure regulator.

Submitter Information Verification

Submitter Full Name: Kevin Carlisle

Organization: Karl Dungs, Inc.

Submittal Date: Tue Nov 13 08:48:01 EST 2012

Copyright Assignment

I, Kevin Carlisle, hereby irrevocably grant and assign to the National Fire Protection Association (NFPA) all and full rights in copyright in thisPublic Comment (including both the Proposed Change and the Statement of Problem and Substantiation). I understand and intend that Iacquire no rights, including rights as a joint author, in any publication of the NFPA in which this Public Comment in this or another similar orderivative form is used. I hereby warrant that I am the author of this Public Comment and that I have full power and authority to enter intothis copyright assignment.

By checking this box I affirm that I am Kevin Carlisle, and I agree to be legally bound by the above Copyright Assignment and the termsand conditions contained therein. I understand and intend that, by checking this box, I am creating an electronic signature that will, upon mysubmission of this form, have the same legal force and effect as a handwritten signature

* A low-pressure limit control for engines with a 732 kW (2.5 million Btu/hr) full-load input orgreater

* A high-pressure limit control (manual reset) for engines with a 732 kW (2.5 million Btu/hr)full-load input or greater

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Public Comment No. 12-NFPA 37-2012 [ Section No. 5.2.2 ]

5.2.2

For engines operating at more than a gauge pressure of 14 kPa (2 psi) inlet gas pressure to theequipment isolation valve , either

( a ) a vent valve shall be provided between the two ASSVs

. This

(b) at least one safety valve shall be fitted with a proof of closure switch, or

(c) a listed valve proving system (VPS) shall be installed to prove the two ASSVs upon each startupor after each shutdown.The vent valve shall fail open without an externally supplied source of powerand shall discharge outdoors.

Statement of Problem and Substantiation for Public Comment

A proof of closure switch is a safety device that can proof the position of the safety shutoff valve to prove that it is has not failed to close.

Submitter Information Verification

Submitter Full Name: Kevin Carlisle

Organization: Karl Dungs, Inc.

Submittal Date: Tue Nov 13 08:42:13 EST 2012

Copyright Assignment

I, Kevin Carlisle, hereby irrevocably grant and assign to the National Fire Protection Association (NFPA) all and full rights in copyright in thisPublic Comment (including both the Proposed Change and the Statement of Problem and Substantiation). I understand and intend that Iacquire no rights, including rights as a joint author, in any publication of the NFPA in which this Public Comment in this or another similar orderivative form is used. I hereby warrant that I am the author of this Public Comment and that I have full power and authority to enter intothis copyright assignment.

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Public Comment No. 11-NFPA 37-2012 [ Section No. 5.3.1.2 ]

5.3.1.2*

The following devices shall not be required to be vented to the outside when installed in accordancewith their listing:

(1) Any regulator or zero governor that operates with gas pressure on both sides of the diaphragm

(2) A full lock-up regulator

(3) A listed regulator incorporating a with a listed vent-limiting device

(4) A regulator incorporating a vent limiting system orificed for 2.5 ft 3 /hr or less, based on naturalgas.

Statement of Problem and Substantiation for Public Comment

Revision makes the requirement performance based.

Submitter Information Verification

Submitter Full Name: Kevin Carlisle

Organization: Karl Dungs, Inc.

Submittal Date: Tue Nov 13 08:39:10 EST 2012

Copyright Assignment

I, Kevin Carlisle, hereby irrevocably grant and assign to the National Fire Protection Association (NFPA) all and full rights in copyright in thisPublic Comment (including both the Proposed Change and the Statement of Problem and Substantiation). I understand and intend that Iacquire no rights, including rights as a joint author, in any publication of the NFPA in which this Public Comment in this or another similar orderivative form is used. I hereby warrant that I am the author of this Public Comment and that I have full power and authority to enter intothis copyright assignment.

By checking this box I affirm that I am Kevin Carlisle, and I agree to be legally bound by the above Copyright Assignment and the termsand conditions contained therein. I understand and intend that, by checking this box, I am creating an electronic signature that will, upon mysubmission of this form, have the same legal force and effect as a handwritten signature

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Public Comment No. 10-NFPA 37-2012 [ Section No. 5.3.2 ]

5.3.2

When the gas pressure on the upstream side of a non-full lock-up regulator is more than a gaugepressure of 3.5 kPa (0.5 psi), a relief valve shall be installed on the downstream side of theregulator. This token relief valve shall vent to the outside of the structure at a point at least 1.5 m (5ft) away from any structure opening.

5.3.2.1

Such relief valves and any connected piping shall be sized to vent the required volume of gas.

Statement of Problem and Substantiation for Public Comment

Clarified the type of relief valve used for the purpose of eliminating high lockup pressures.

Submitter Information Verification

Submitter Full Name: Kevin Carlisle

Organization: Karl Dungs, Inc.

Submittal Date: Tue Nov 13 08:37:40 EST 2012

Copyright Assignment

I, Kevin Carlisle, hereby irrevocably grant and assign to the National Fire Protection Association (NFPA) all and full rights in copyright in thisPublic Comment (including both the Proposed Change and the Statement of Problem and Substantiation). I understand and intend that Iacquire no rights, including rights as a joint author, in any publication of the NFPA in which this Public Comment in this or another similar orderivative form is used. I hereby warrant that I am the author of this Public Comment and that I have full power and authority to enter intothis copyright assignment.

By checking this box I affirm that I am Kevin Carlisle, and I agree to be legally bound by the above Copyright Assignment and the termsand conditions contained therein. I understand and intend that, by checking this box, I am creating an electronic signature that will, upon mysubmission of this form, have the same legal force and effect as a handwritten signature

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Public Comment No. 6-NFPA 37-2012 [ Section No. A.4.1.4(2) ]

A.4.1.4(2)

Means of demonstrating compliance are by means of full-scale fire tests or by calculationprocedures, such as those given in NFPA 555, Guide on Methods for Evaluating Potential for RoomFlashover.

This annex section refers to the calculation procedure in NFPA 555, not to NFPA 555 per se. The physics ofthe situation under consideration in NFPA 555 are the same as the physics of evaluating the risk that a firewill ignite a nearby building. The calculation procedure in NFPA 555 (chapter 10 of the 2013 edition of NFPA555) is similar to the Radiant Ignition of a Near Fuel algorithm in NIST's FPETOOL for calculating ignitionfrom a nearby fire. It is a sound, engineering-based method of predicting the risk of ignition from a fire.

The values in NFPA 37 section 4.1.4 and the reference to the NFPA 555 calculation method are the result ofcalculations presented to the committee in 1996. The calculations treated an engine fire as a verticalcylinder. The values in 4.1.4 changed somewhat in the 1998 edition of NFPA 37, based on thosecalculations. They are reasonably consistent with the requirements of the BOCA building code, which wasin effect at the time.

The committee wanted to include a performance alternative in NFPA 37. The reference in this annexsection to the NFPA 555 method provides guidance on how to evaluate proposed alternatives. .

The committee chose NFPA 555 as the reference because that is the method that was used to support thechanges in the 1998 edition. The committee also thought NFPA 555 would be the most convenient sourcefor our users and more accessible than the primary sources that went into developing the NFPA 555calculation method as presented in the 1996 ROP.

Statement of Problem and Substantiation for Public Comment

In recent years, users have asked questions of the staff liaison about the reference to NFPA 555 at least twice. The proposed new language adds the response to those inquiries to the annex so it will be available for all users.

Submitter Information Verification

Submitter Full Name: KENNETH ELOVITZ

Organization:

Submittal Date: Sun Nov 04 10:18:28 EST 2012

Copyright Assignment

I, KENNETH ELOVITZ, hereby irrevocably grant and assign to the National Fire Protection Association (NFPA) all and full rights incopyright in this Public Comment (including both the Proposed Change and the Statement of Problem and Substantiation). I understandand intend that I acquire no rights, including rights as a joint author, in any publication of the NFPA in which this Public Comment in this oranother similar or derivative form is used. I hereby warrant that I am the author of this Public Comment and that I have full power andauthority to enter into this copyright assignment.

By checking this box I affirm that I am KENNETH ELOVITZ, and I agree to be legally bound by the above Copyright Assignment and theterms and conditions contained therein. I understand and intend that, by checking this box, I am creating an electronic signature that will,upon my submission of this form, have the same legal force and effect as a handwritten signature

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Public Comment No. 8-NFPA 37-2012 [ Section No. A.4.1.4(2) ]

A.4.1.4(2)

Means of demonstrating compliance are by means of full-scale fire tests or by calculationCalculation procedures, such as those given in NFPA 555, Guide on Methods for EvaluatingPotential for Room Flashover, are useful tools to assess the probability of safe engine placement .

Statement of Problem and Substantiation for Public Comment

This is tied to the proposed change to 4.1.4, and the criteria for the test method are proposed to be shown in the body of the standard.

Related Public Comments for This Document

Related Comment Relationship

Public Comment No. 7-NFPA 37-2012 [Section No. 4.1.4]

Related Items from the Public Input Stage for This Document

Related Item

Public Input No. 2-NFPA 37-2012 [Section No. A.4.1.4(2)]

Submitter Information Verification

Submitter Full Name: Marcelo Hirschler

Organization: GBH International

Submittal Date: Sun Nov 04 23:30:27 EST 2012

Copyright Assignment

I, Marcelo Hirschler, hereby irrevocably grant and assign to the National Fire Protection Association (NFPA) all and full rights in copyright inthis Public Comment (including both the Proposed Change and the Statement of Problem and Substantiation). I understand and intend thatI acquire no rights, including rights as a joint author, in any publication of the NFPA in which this Public Comment in this or another similaror derivative form is used. I hereby warrant that I am the author of this Public Comment and that I have full power and authority to enter intothis copyright assignment.

By checking this box I affirm that I am Marcelo Hirschler, and I agree to be legally bound by the above Copyright Assignment and theterms and conditions contained therein. I understand and intend that, by checking this box, I am creating an electronic signature that will,upon my submission of this form, have the same legal force and effect as a handwritten signature

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Public Comment No. 9-NFPA 37-2012 [ Section No. A.5.1 ]

A.5.1

Gaseous-fueled engines are those engines in which the fuel supply is delivered to the engine invapor 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., land fill and digester gas) For biogas applications, see CSA 149.6, Code forDigester 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 forengines.

Piping systems supplying gaseous fuels should be designed to minimize piping failure. Severalexamples of methods for minimizing piping failure are as follows:

(1) Welded pipe joints should be used where practical. Threaded couplings and bolted flangesshould 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 asbetween rigid pipe supply lines and manifolds or other points connection to the engine.

(3) Rigid piping connected directly to the engine should be supported so that failures will not occurdue 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 supplyin the piping upstream of the equipment isolation valve, refer to NFPA 56PS, Standard for Fire andExplosion Prevention During Cleaning and Purging of Flammable Gas Piping Systems.

Statement of Problem and Substantiation for Public Comment

This standard specifically deals with the generation, handling and utilization of biogas, and it contains provisions unique to biogas.

Submitter Information Verification

Submitter Full Name: Kevin Carlisle

Organization: Karl Dungs, Inc.

Submittal Date: Tue Nov 13 08:34:58 EST 2012

Copyright Assignment

I, Kevin Carlisle, hereby irrevocably grant and assign to the National Fire Protection Association (NFPA) all and full rights in copyright in thisPublic Comment (including both the Proposed Change and the Statement of Problem and Substantiation). I understand and intend that Iacquire no rights, including rights as a joint author, in any publication of the NFPA in which this Public Comment in this or another similar orderivative form is used. I hereby warrant that I am the author of this Public Comment and that I have full power and authority to enter intothis copyright assignment.

By checking this box I affirm that I am Kevin Carlisle, and I agree to be legally bound by the above Copyright Assignment and the termsand conditions contained therein. I understand and intend that, by checking this box, I am creating an electronic signature that will, upon mysubmission of this form, have the same legal force and effect as a handwritten signature

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Public Comment No. 3-NFPA 37-2012 [ New Section after A.9.3.1 ]

TITLE OF NEW CONTENT

A.9.3.2 {Please provide clarification as to how 9.3.2(4) does not contradict 9.3.1.1}

Statement of Problem and Substantiation for Public Comment

I have not provided a proposed change, rather, I am requesting clarification in Appendix A.9.3.2 . Specifically, how does 9.3.2(4) coexist with the exception granted in 9.3.1.1 regarding a unit trip due to loss of flame?

Submitter Information Verification

Submitter Full Name: MICHAEL KRUGER

Organization: EXELON POWER

Submittal Date: Mon Sep 24 10:44:15 EDT 2012

Copyright Assignment

I, MICHAEL KRUGER, hereby irrevocably grant and assign to the National Fire Protection Association (NFPA) all and full rights in copyrightin this Public Comment (including both the Proposed Change and the Statement of Problem and Substantiation). I understand and intendthat I acquire no rights, including rights as a joint author, in any publication of the NFPA in which this Public Comment in this or anothersimilar or derivative form is used. I hereby warrant that I am the author of this Public Comment and that I have full power and authority toenter into this copyright assignment.

By checking this box I affirm that I am MICHAEL KRUGER, and I agree to be legally bound by the above Copyright Assignment and theterms and conditions contained therein. I understand and intend that, by checking this box, I am creating an electronic signature that will,upon my submission of this form, have the same legal force and effect as a handwritten signature

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Additional Issues

NFPA 37-2010

1. From Ron Shaffer, based on questions relating to Paragraph 4.1.4(1) of NFPA 37: Subsection 4.1.4 requires 5-foot separation from openings in walls and from combustible walls, but 4.1.4(1) says nothing about openings. Therefore, 4.1.4(1) trumps the 5-foot requirement if wall is 1-hour rated, even if there is an opening within 5 feet of the engine. This needs to be rectified.

2. From Ron Shaffer, based on customer inquiry: How large can a base tank be? Can NFPA 37 even address this issue. Issue originated from a customer inquiry on seismic performance of a diesel-driven generator proposed to be supplied with a base tank. Generator is 2000 KW with 3000 HP driver, burning ≈ 100 gallons/hr.

bbenedetti
Text Box
Attachment No. A13