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
2、S AND DISCLAIMERS CONCERNING NFPA STANDARDS NOTICE AND DISCLAIMER OF LIABILITY CONCERNING THE USE OF NFPA STANDARDS NFPA codes, standards, recommended practices, and guides (“NFPA Standards”), of which the document contained herein is one, are developed through a consensus standards development proc
3、ess approved by the American National Standards Institute. This process brings together volunteers representing varied viewpoints and interests to achieve consensus on fire and other safety issues. While the NFPA administers the process and establishes rules to promote fairness in the development of
4、 consensus, it does not independently test, evaluate, or verify the accuracy of any information or the soundness of any judgments contained in NFPA Standards. The NFPA disclaims liability for any personal injury, property or other damages of any nature whatsoever, whether special, indirect, conseque
5、ntial or compensatory, directly or indirectly resulting from the publication, use of, or reliance on NFPA Standards. The NFPA also makes no guaranty or warranty as to the accuracy or completeness of any information published herein. In issuing and making NFPA Standards available, the NFPA is not und
6、ertaking to render professional or other services for or on behalf of any person or entity. Nor is the NFPA undertaking to perform any duty owed by any person or entity to someone else. Anyone using this document should rely on his or her own independent judgment or, as appropriate, seek the advice
7、of a competent professional in determining the exercise of reasonable care in any given circumstances. The NFPA has no power, nor does it undertake, to police or enforce compliance with the contents of NFPA Standards. Nor does the NFPA list, certify, test, or inspect products, designs, or installati
8、ons for compliance with this document. Any certification or other statement of compliance with the requirements of this document shall not be attributable to the NFPA and is solely the responsibility of the certifier or maker of the statement. REMINDER: UPDATING OF NFPA STANDARDS Users of NFPA codes
9、, standards, recommended practices, and guides (“NFPA Standards”) should be aware that NFPA Standards may be amended from time to time through the issuance of Tentative Interim Amendments or corrected by Errata. An official NFPA Standard at any point in time consists of the current edition of the do
10、cument together with any Tentative Interim Amendment and any Errata then in effect. In order to determine whether an NFPA Standard has been amended through the issuance of Tentative Interim Amendments or corrected by Errata, visit the Document Information Pages on NFPAs website. The Document Informa
11、tion Pages provide up-to-date, document specific information including any issued Tentative Interim Amendments and Errata. To access the Document Information Page for a specific NFPA Standard, go to http:/www.nfpa.org/docinfo to choose from the list of NFPA Standards or use the search feature on the
12、 right to select the NFPA Standard number (e.g., NFPA 101). In addition to posting all existing Tentative Interim Amendments and Errata, the Document Information Page also includes the option to sign-up for an “Alert” feature to receive an email notification when new updates and other information ar
13、e posted regarding the document.1/14 IMPORTANT NOTICES AND DISCLAIMERS CONCERNING NFPA STANDARDS ADDITIONAL NOTICES AND DISCLAIMERS Updating of NFPA Standards Users of NFPA codes, standards, recommended practices, and guides (“NFPA Standards”) should be aware that these documents may be superseded a
14、t any time by the issuance of new editions or may be amended from time to time through the issuance of Tentative Interim Amendments or corrected by Errata. An official NFPA Standard at any point in time consists of the current edition of the document together with any Tentative Interim Amendments an
15、d any Errata then in effect. In order to determine whether a given document is the current edition and whether it has been amended through the issuance of Tentative Interim Amendments or corrected through the issuance of Errata, consult appropriate NFPA publications such as the National Fire Codes S
16、ubscription Service, visit the NFPA website at www.nfpa.org, or contact the NFPA at the address listed below. Interpretations of NFPA Standards A statement, written or oral, that is not processed in accordance with Section 6 of the Regulations Governing the Development of NFPA Standards shall not be
17、 considered the official position of NFPA or any of its Committees and shall not be considered to be, nor be relied upon as, a Formal Interpretation. Patents The NFPA does not take any position with respect to the validity of any patent rights referenced in, related to, or asserted in connection wit
18、h an NFPA Standard. The users of NFPA Standards bear the sole responsibility for determining the validity of any such patent rights, as well as the risk of infringement of such rights, and the NFPA disclaims liability for the infringement of any patent resulting from the use of or reliance on NFPA S
19、tandards. NFPA adheres to the policy of the American National Standards Institute (ANSI) regarding the inclusion of patents in American National Standards (“the ANSI Patent Policy”), and hereby gives the following notice pursuant to that policy: NOTICE: The users attention is called to the possibili
20、ty that compliance with an NFPA Standard may require use of an invention covered by patent rights. NFPA takes no position as to the validity of any such patent rights or as to whether such patent rights constitute or include essential patent claims under the ANSI Patent Policy. If, in connection wit
21、h the ANSI Patent Policy, a patent holder has filed a statement of willingness to grant licenses under these rights on reasonable and nondiscriminatory terms and conditions to applicants desiring to obtain such a license, copies of such filed statements can be obtained, on request, from NFPA. For fu
22、rther information, contact the NFPA at the address listed below. Law and Regulations Users of NFPA Standards should consult applicable federal, state, and local laws and regulations. NFPA does not, by the publication of its codes, standards, recommended practices, and guides, intend to urge action t
23、hat is not in compliance with applicable laws, and these documents may not be construed as doing so. Copyrights NFPA Standards are copyrighted. They are made available for a wide variety of both public and private uses. These include both use, by reference, in laws and regulations, and use in privat
24、e self-regulation, standardization, and the promotion of safe practices and methods. By making these documents available for use and adoption by public authorities and private users, the NFPA does not waive any rights in copyright to these documents. Use of NFPA Standards for regulatory purposes sho
25、uld be accomplished through adoption by reference. The term “adoption by reference” means the citing of title, edition, and publishing information only. Any deletions, additions, and changes desired by the adopting authority should be noted separately in the adopting instrument. In order to assist N
26、FPA in following the uses made of its documents, adopting authorities are requested to notify the NFPA (Attention: Secretary, Standards Council) in writing of such use. For technical assistance and questions concerning adoption of NFPA Standards, contact NFPA at the address below. For Further Inform
27、ation All questions or other communications relating to NFPA Standards and all requests for information on NFPA procedures governing its codes and standards development process, including information on the procedures for requesting Formal Interpretations, for proposing Tentative Interim Amendments,
28、 and for proposing revisions to NFPA standards during regular revision cycles, should be sent to NFPA headquarters, addressed to the attention of the Secretary, Standards Council, NFPA, 1 Batterymarch Park, P.O. Box 9101, Quincy, MA 02269-9101; email: stds_adminnfpa.org For more information about NF
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
