1、THERMOSET FRP DUCT CONSTRUCTION MANUALSHEET METAL AND AIR CONDITIONING CONTRACTORS NATIONAL ASSOCIATION, INC. www.smacna.orgANSI/SMACNA 011-2017THERMOSET FRP DUCT CONSTRUCTION MANUALSECOND EDITION 2016SHEET METAL AND AIR CONDITIONING CONTRACTORS NATIONAL ASSOCIATION, INC.4201 Lafayette Center DriveC
2、hantilly, VA 20151 1219www.smacna.orgTHERMOSET FRP DUCT CONSTRUCTION MANUALCOPYRIGHT 2016All Rights ReservedbySHEET METAL AND AIR CONDITIONING CONTRACTORS NATIONAL ASSOCIATION, INC.4201 Lafayette Center DriveChantilly, VA 20151 1219Printed in the U.S.A.FIRST EDITION 1997SECOND EDITION 2016ISBN 978-1
3、-61721-120-1 PrintISBN 978-1-61721-121-8 PDFExcept as allowed in the Notice to Users and in certain licensing contracts, no part of this book may be reproduced, stored in a retrievable system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise,
4、 without the prior written permission of the publisher.Thermoset FRP Duct Construction Manual Second Edition iiiFOREWORDThis is the second edition of the Thermoset FRP Duct Construction Manual with the fi rst edition published in 1997. As with the fi rst edition, this second edition is an authoritat
5、ive manual that design engineers, industrial engineering departments, pollution control authorities, FRP manufactures and installation contractors can rely upon for the proper selection, manufacture, and installation of FRP duct systems. Key updates of this second edition include: Recognize the incr
6、eased use of FRP ductwork in commercial/HVAC applications. New language is included on FRP ductwork for commercial/HVAC applications. Chapter added covering underground FRP duct installation Round duct sizes are expanded to 96 in. Hanger and Support section is now expanded into a separate chapter. U
7、pper attachments are now covered. Rectangular and round duct hanger tables added for easier selection. Hanger bar and hanger rod sizes increased. Riser support details added Rectangular duct stiffener tables are added for easier selection Appendix added indicating information on extended hanger spac
8、ing Appendix added indicating general information on safe handling of thermoset fi berglass reinforced plastic duct Glossary updatedSMACNA thanks the SMACNA contractors who, as members of the Thermoset FRP Duct Construction Task Force, volunteered their time and effort to the development of this man
9、ual. SMACNA appreciates their dedication and willingness to share their knowledge and experience in the fabrication and installation of Thermoset FRP Ductwork.SHEET METAL AND AIR CONDITIONING CONTRACTORS NATIONAL ASSOCIATION, INC.iv Thermoset FRP Duct Construction Manual Second EditionFRP TASK FORCE
10、CONSULTANTAndy Groh, ChairpersonAlthoff Industries, Inc.Crystal Lake, ILTerry CahillCrawford CompanyRock Island, ILBrian FlannaganPrimary Plastics, Inc.Endwell, NYBrian LindholmStreimer Sheet Metal Works, Inc.Portland, OregonShawn OHara, Staff LiaisonSMACNAChantilly, VAJoseph M. Plecnik, PhD, P.E.Te
11、sting, Inspection constructing the ductwork in conformance with the FRP DCS, and; notwithstanding the inherent low leakage of FRP ducts, identifying joints and duct wall penetra-tions which require sealer and sealing the ductwork properly.The designer is responsible for determining the pres-sure cla
12、ss or classes required for duct construction and Thermoset FRP Duct Construction Manual Second Edition 1.3for evaluating the amount of sealing necessary to achieve system performance objectives. It is recom-mended that all FRP ducts used in commercial HVAC applications operating at 1 in. (250 Pa) an
13、d in. (125 Pa) pressure class meet Seal Class C. However, because designers sometimes deem leakage in unsealed ducts not to have adverse effects, the sealing of all ducts in the 1 in. (250 Pa) and in. (125 Pa) pressure class is not required by the FRP DCS. When Seal Class C is to apply to all 1 in.
14、(250 Pa) and in. (125 Pa) pressure class duct, the designer must require this in the project specifi cation. The designer should review the ANSI/SMACNA HVAC Air Duct Leakage Test Manual for estimated and practical leakage allowances. Specifi c to duct sealing, if the designer does not desig-nate a p
15、ressure class for duct construction on the con-tract drawings, the basis of compliance with the FRP DCS is as follows: 2 in. wg (500 Pa) for all ducts between the supply fan and any terminal unit and 1 in. wg (250 Pa) for all other ducts of any application.Some sealants can adversely affect the rele
16、ase func-tion of breakaway connections to fi re dampers; consult the damper manufacturer for installation restrictions.For standard duct sealing requirements for commer-cial HVAC applications, reference Table 1-1.1.8 DUCT LEAKAGE TESTS1.8.1 FRP ducts used in process/corrosive applicationsIf FRP duct
17、s used in process/corrosive application require duct leakage tests, the contract documents must clearly designate the portions of the system(s) to be tested and the appropriate method of test and the appropriate test pass/fail criteria.1.8.2 FRP ducts used in commercial HVAC applicationsFor FRP duct
18、s used in commercial HVAC applications and constructed in accordance with the FRP DCS, there is no need to verify leakage control by fi eld testing when adequate methods of FRP fabrication and assembly are used. Leakage tests are an added expense in system installation. It is not recommended that du
19、ct systems constructed to 3 in. wg (750 Pa) class or lower be tested because this is generally not cost effective. For duct systems constructed to 4 in. wg (1000 Pa) class and higher, the designer must deter-mine if any justifi cation for testing exists. If it does, the contract documents must clear
20、ly designate the por-tions of the system(s) to be tested and the appropriate test methods. ASHRAE energy conservation standards series 90 text on leakage control generally requires tests only for pressures in excess of 3 in. wg (750 Pa).The ANSI/SMACNA HVAC Air Duct Leakage Test Manual as necessaril
21、y altered to incorporate FRP ducts, provides practical and detailed procedures for conducting leakage tests.Note for the Designer: For duct leakage testing, the test pressure shall not exceed the duct construction pressure class. The designer must specify duct system pressure relief procedures and p
22、recautions to protect and prevent duct systems from over pressurization.Note: For underground FRP duct installations, required duct leakage testing procedures shall be completed and approved prior to commencing backfi ll procedures. 1.9 CONTENTSThe manual is subdivided into twelve chapters and nine
23、appendices, which are briefl y described as follows:Seal Class Sealing Requirements Applicable Static Pressure Construction ClassA Class A: All Transverse joints, longitudinal seams, and duct wall penetrations4 in. wg and up (1000 Pa)B Class B: All Transverse joints and longitudinal seams only3 in.
24、wg (750 Pa)C Class C: Transverse joints only 2 in. wg (500 Pa)Table 11 Standard Duct Sealing Requirements For Commercial HVAC ApplicationsIn addition to the above, any duct systems up to 1 in. wg (250 Pa) construction class that is upstream of terminal units shall meet Seal Class C.1.4 Thermoset FRP
25、 Duct Construction Manual Second EditionCHAPTER 1, INTRODUCTIONThe introduction outlines the format and layout of the manual, with a brief description of “FRP” and a sum-mary of the contents of each chapter.CHAPTER 2, MATERIALSThis chapter contains a description of thermoset res-ins, catalyst and pr
26、omoter systems required to cure the thermoset resins, types of additives used and a brief description of reinforcement materials used to fabri-cate FRP duct.CHAPTER 3, LAMINATE CONSTRUCTIONThis chapter outlines the proper layup sequence for corrosion resistant composite laminates for FRP duct applic
27、ations in conformance with ASTM C582 Tables 1, 2 and 4. These are reprinted in Chapter 3, courtesy of ASTM as Tables 3-1, 3-2 and 3-3, respectively.CHAPTER 4, JOINING PROCEDURESProcedures for joining FRP Duct using the buttandwrap or socket hand layup fabrication methods in the fi eld.CHAPTER 5, DES
28、IGN OF ROUND FRP DUCTa. Design of round (cylindrical) FRP ducts using Type I and Type II laminates.b. Design of round (cylindrical) FRP ducts using Filament Wound (Type X) laminates.CHAPTER 6, DESIGN OF RECTANGULAR FRP DUCTa. Design of rectangular FRP duct using Type I and Type II laminates.b. Desig
29、n of stiffeners for rectangular FRP ducts using Type II laminates.CHAPTER 7, FLANGES AND FITTINGSThis chapter discusses FRP fl anges and fi ttings for round and rectangular duct construction.CHAPTER 8, HANGERS AND SUPPORTSHangers and support requirements for FRP round and rectangular ducts installed
30、 horizontally and vertically. Information includes details on upper attachments, hanger straps and rods and lower attachments. CHAPTER 9, COMPONENTS AND ACCESSORIESThis section includes FRP construction standards for fume hoods, dampers, access doors, end caps, louvers, exhaust stacks, fl exible con
31、nectors and fl exible materials. CHAPTER 10, SPECIALTY SYSTEMSIncreasingly FRP duct is used in underground applica-tions. This chapter is devoted to underground FRP duct installation as well as covering other specialty systems such as FRP condensate drainage, FRP sprin-kler systems and FRP drainage
32、systems.CHAPTER 11, QUALITY CONTROL AND OWNER INSPECTIONSThis chapter covers quality control requirements and owner inspections. CHAPTER 12, FRP GUIDE SPECIFICATIONSGuide specifi cations for fi berglass reinforced plastic air-handling systems.APPENDIX A, DEVELOPMENT OF THE TABLESComplete summary of
33、the criteria used for the estab-lishment of the FRP Duct Construction Tables and the test program that verifi ed the design concepts and the table data.APPENDIX B, CHEMICAL RESISTANCE OF FRP DUCTChemical resistance of FRP duct, resin selection guide.APPENDIX C, ALTERNATE ROUND DUCT DESIGN TABLESComp
34、lete set of alternate round duct design tables based on a higher safety factor (SF = 5.0) than that used for the design tables of Chapter 5 (SF =4.0).APPENDIX D, EXTENDED HANGER SPACINGTable D-1 indicating extended hanger spacing for round FRP ducts.Thermoset FRP Duct Construction Manual Second Edit
35、ion 1.5APPENDIX E, SAFE HANDLING OF FRP DUCTSAPPENDIX E is an update of SMACNAs Safe Handling of Fiberglass Reinforced Plastic (FRP).APPENDIX F, ALLOWABLE DEFECTSStandard practice for acceptable criteria for visual inspection of components produced from molded glass-reinforced plastic laminates.APPE
36、NDIX G, GLOSSARYGlossary of terms.APPENDIX H, REFERENCED DOCUMENTSComplete list of documents referenced throughout this manual.APPENDIX I, FORMER COMMITTEE MEMBERS AND OTHER CONTRIBUTORS1.6 Thermoset FRP Duct Construction Manual Second EditionTHIS PAGE INTENTIONALLY LEFT BLANKCHAPTER 2MATERIALSTherm
37、oset FRP Duct Construction Manual Second Edition 2.1CHAPTER 2 MATERIALS2.1 INTRODUCTIONThe use of thermoset FRP ducting to handle corrosive fumes dates back to the 1950s. These thermoset mate-rials offer similar corrosion resistance and physical strength properties when compared to thermoplastic mat
38、erials. Both are identifi ed as “plastics.” However, there is a signifi cant difference during the forming and fabrication stage of each product.While thermoplastic components are formed using solid shapes in a manner similar to metallic fabrication, the thermoset resins are supplied in liquid form,
39、 which when combined with fi berglass reinforcement, forms a com-posite laminate, when applied to a rigid mold surface.Fabricators of FRP composite laminates require spe-cial skills and training to handle catalysts (initiators) and promoters in order to understand the chemistry of room temperature c
40、uring systems.The catalyzed resin is combined with fi berglass rein-forcement and laid on a solid form, allowed to cure, then removed for installation in the fi eld. Following layup techniques, the FRP components are joined together at the job site using a fi eld wrap of overlapping plies of materia
41、l. The thickness of the overwrap joint should at least equal the thickness of the duct laminate.Thermoset laminates do not melt when heated. They generally retain their physical strength and integrity at elevated temperatures.The resistance of FRP composite laminates to aggres-sive corrosive environ
42、ments is a primary reason for specifying FRP duct over other alternative materials. FRP duct can be used to handle a wide range of chem-icals, at varying elevated temperatures depending on the type of thermosetting resin selected.The FRP duct can be designed and fabricated to pro-vide for chemical r
43、esistance, fl ame retardance, surface conductivity, weathering, abrasion resistance and external chemical attack from spillage.Successful long term laminate performance requires selection of the correct thermosetting resin to handle the chemical and temperature conditions, and also the proper design
44、, fabrication, and fi eld installation of the FRP duct system.2.2 THERMOSET RESINSResin shall be a commercialgrade thermoset that has been tested in accordance with ASTM C581 or that has been previously documented to be acceptable for the service conditions. Where no test or service infor-mation is
45、available, the end user shall agree to select a suitable resin with the fabricator.The resin may contain fi llers or thixotropic agents as approved by the resin manufacturer. When required, fi re retardant synergists may also be added to the resin to reduce fl ame spread.There are various types of t
46、hermoset resins used for fabricating FRP duct. Each of the generic types of res-ins used today offer different properties to be consid-ered when selecting a suitable resin for a specifi c application, e.g., concentration of chemical environs to be handled and range of temperatures to which the FRP d
47、uct will be exposed. Any questionable appli-cations should be resolved with the resin supplier.Thermosetting resin selection is based by the chemical service and environment which FRP ductwork will be exposed. For resin selection including applications which are sever or questionable, its incumbent
48、on the designer rather than the fabricator to evaluate and specify the acceptable resin or equivalent alternate resins. If the corrosive conditions are very severe, then chemical testing may be necessary to determine a suit-able thermosetting resin to handle the application. In extreme cases, consid
49、er a dual laminate, using a more corrosion resistant thermoplastic liner in place of the standard FRP corrosion barrier, with an FRP outer structural laminate for strength.In some applications, a “Corrosion Allowance” con-sisting of one to two additional plies of 11/2 oz chopped strand mat is added to the corrosion barrier to combat permeation effects. The added thickness pro-vides corrosion protection and maintains the structural integrity of the FRP laminate.For resin producers technical assistance with resin selection, the following mi
