NFPA 91-2015 Standard for Exhaust Systems for Air Conveying of Vapors Gases Mists and Particulate Solids (Effective Date 12 1 2014).pdf

1、NFPA 91 Standard for Exhaust Systems for Air Conveying of Vapors, Gases, Mists, and Particulate Solids 2015 Edition NFPA , 1 Batterymarch Park, Quincy, MA 02169-7471, USA An International Codes and Standards Organization 1/14 ISBN: 978-145591039-7 (Print) ISBN: 978-145591085-4 (PDF) IMPORTANT NOTICE

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29、PA, visit the NFPA website at www.nfpa.org. All NFPA codes and standards can be viewed at no cost at www.nfpa.org/freeaccess.Copyright 2014 National Fire Protection Association . All Rights Reserved. NFPA 91 Standardfor ExhaustSystemsforAirConveyingofVapors,Gases,Mists,and ParticulateSolids 2015Edit

30、ion This edition of NFPA 91,StandardforExhaustSystemsforAirConveyingofVapors,Gases,Mists, and Particulate Solids, was prepared by the Technical Committee on Handling and Conveying of Dusts, Vapors, and Gases and released by the Correlating Committee on Combustible Dusts. It was issued by the Standar

31、ds Council on November 11, 2014, with an effective date of December 1, 2014, and supersedes all previous editions. This edition of NFPA 91 was approved as an American National Standard on December 1, 2014. OriginandDevelopmentofNFPA91 The National Fire Protection Association as early as 1899 recogni

32、zed the hazards of blower and exhaust systems. Since 1900, the NFPA Committee on Blower Systems has given continu- ing attention to the subject. Following World War II, revisions and additions to the standard were recommended by the NFPA Committee on Blower Systems to cover various new devel- opment

33、s in the protection of dust collecting systems and stock and refuse conveying systems, and were adopted by the NFPA at its Annual Meetings in 1946, 1947, 1948, and 1949. Editori- ally revised editions were published in 1959 and 1961. In 1972, Section 200 (Chapter 2) was expanded, and a new Section 5

34、00 (Chapter 5), covering systems involving plastic materials, was added. In the 1973 edition, Section 400 (Chapter 4) was completely revised. The 1983 edition was completely updated to conform with the NFPAManual of Style and incorporated minor revisions in each chapter. The 1990 edition included mi

35、nor revisions to Chapter 2 including a new Figure 2-8 and Table 2-8(b). Changes were made to recognize NFPA 45, Standard on Fire Protection forLabora- tories Using Chemicals, and to remove conflicts with that standard. These changes included moving Section 5-2 and Figures 5-2 through 5-5 to Appendix

36、 A. The Technical Committee on Blower Systems completely revised the standard for the 1992 edition, including a new title and new scope. The previous title had been Standard for the InstallationofBlowerandExhaustSystemsforDust,Stock,andVaporRemovalorConveying. Chapters 3 and 4 from the 1990 edition

37、were deleted with some requirements from those chapters included in the revised and reorganized Chapter 2 and new Chapters 5, 6, and 7. Minor changes were made to all chapters in the 1995 edition. The Committee clarified their intent that ducts can be round, oval, or rectangular. A new figure was ad

38、ded to show access openings for different shapes of ducts, and a new table was added in the appendix to show duct velocities for types of materials conveyed. The 1999 edition incorporated a new scope limiting the applicability of this document to noncombustible particulate solids. The Committee on H

39、andling and Conveying of Dusts, Vapors, and Gases became responsible for NFPA 91 and made changes consistent with the committees other documents, NFPA 650,StandardforPneumaticConveyingSystemsforHandling CombustibleParticulateSolids, and NFPA 654,StandardforthePreventionofFireandDustExplosions from t

40、he Manufacturing, Processing, and Handling of Combustible Particulate Solids, that address combustible particulate solids. In the 2004 revision, the Committee completed changes according to the Manual of Style for NFPA Technical Committee Documents and the conditions under which flammable con- centr

41、ations can exceed 25 percent of the lower flammable limit (LFL) were expanded to match provisions in other NFPA documents. The design requirements for duct hanging and bracing and fire protection requirements for ducting were also updated. 911 NFPA and National Fire Protection Association are regist

42、ered trademarks of the National Fire Protection Association, Quincy, Massachusetts 02169.The 2010 edition contained extensive revisions to Chapter 4 on exhaust system design and construction. These revisions brought requirements from the complementary document on pneumatic conveying systems, NFPA 65

43、4, to this standard for correlation and consistency. The Committee also added a new chapter on AirMaterial Separators (Chapter 7) using concepts from NFPA 654. Chapter 9 was revised to be made retroactive and to establish require- ments for testing frequency. Other changes were made make the standar

44、d consistent with the Manual of Style forNFPA Technical Committee Documents. The 2015 edition includes a revision to both the document title and the scope to remove confusion for users of NFPA 91 when designing pneumatic conveying, duct systems, or air moving devices for application within the commo

45、dity-specific combustible dust standards. The standard now applies to particulate solids, whether combustible or noncombustible. The committee used information provided by FM Global Data Sheet to include alternative meth- ods in two applications: (1) protecting ducts that pass through fire barriers

46、so as to maintain the fire resistance rating of the barrier and (2) strengthening ducts where sprinklers are installed and discharge within the ducts system in order to maintain support for the ducting with the accumulated weight of the discharge water. The Committee added and revised definitions fo

47、r consistency with the commodity-specific combustible dust standards. The Committee also reviewed and updated extracted material in accordance with theManualofStyleforNFPATechnicalCommitteeDocuments. 912 EXHAUST SYSTEMS FOR AIR CONVEYING OF VAPORS, GASES, MISTS, AND PARTICULATE SOLIDS 2015 EditionCo

48、rrelatingCommitteeonCombustibleDusts KevinKreitman, Chair City of Redding Fire Department, CA E ChrisAiken, Cargill, Inc., MN U MatthewJ.Bujewski, MJB Risk Consulting, MO SE JohnM.Cholin, J. M. Cholin Consultants Inc., NJ SE GregoryF.Creswell, Titanium Metals Corporation (TIMET), PA M ScottG.Davis,

49、GexCon US, MD SE HenryL.Febo,Jr., FM Global, MA I WalterL.Frank, Frank Risk Solutions, Inc., DE SE DonaldHayden, Closure Systems International, IN U EdwardR.LaPine, Aon Fire Protection Engineering Corporation, AZ I ArthurP.Mattos,Jr., XL Global Asset Protection Services, NC I JackE.Osborn, Airdusco, Inc., TN M BillStevenson, CV Technology, Inc., FL M JrmeR.Taveau, Fike Corporation, MO M Alternates AmyBrown, FM Global, MA I (Alt. to H. L. Febo, Jr.) CraigFroehling, Cargill, Inc., MN U (Alt. to C. Aiken) JasonKrbec, CV Technology, Inc., FL