ASTM_F_2934_-_12.pdf

Designation:F293412Standard Specification forCircular Metallic Bellows Type Expansion Joint for HVACPiping Applications1This standard is issued under the fixed designation F2934;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This specification establishes the minimum require-ments for the mechanical design,manufacture,inspection andtesting of circular metallic bellows-type expansion joints usedto absorb the dimensional changes resulting from pipingthermal expansion or contraction,as well as the movements ofterminal equipment and supporting structures.1.2 Additional or better features,over and above the mini-mum requirements set by this specification,are not prohibitedby this specification.1.3 The layout of many piping systems provides inherentflexibility through natural changes in direction so that anydisplacements produce primarily bending or torsional strains,within acceptable limits.Where the system lacks this inherentflexibility the designer should then consider adding flexibilitythrough the use of metallic bellows-type expansion joints.1.4 The values stated in inch-pound units are to be regardedas the standard.The values given in parentheses are forinformation only.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASME/ANSI Standards:2B16.25 Butt Welding EndsB16.5 Pipe Flanges and Flanged FittingsB31.1 Power Piping Code2.2 ASME Standard:Section IX Welding and Brazing Qualifications32.3 EJMA Standard:Standards of the Expansion Joint Manufacturers Associa-tion42.4 Pipe Fabrication Institute Standard:ES-3 Fabrication Tolerances53.Terminology3.1 Expansion joint definitions shall be in accordance withthose in the EJMA standards.3.2 externally pressurized expansion jointtypically usedfor straight runs of pipe accommodating axial movement,andincorporate an all stainless steel flexible bellows,an internalguide ring/sleeve,an enclosure with end plates at each end.3.2.1 DiscussionExternally pressurized expansion jointsare typically configured with a service pipe extending throughthe bellows,and the bellows attaching to the end of the servicepipe and the end plate.The external side of the bellows isexposed to the pressure of the medium being conveyed by theservice pipe and the inside of the bellows is exposed toatmosphere.3.3 internally pressurized expansion jointtypically incor-porates an all stainless steel flexible bellows containing thepressure on the internal side.3.3.1 DiscussionInternally pressurized expansion jointscan be configured to accommodate a wide range of move-ments.3.4 double expansion jointexpansion joint consisting oftwo bellows joined by a common connector.3.4.1 DiscussionThe common connector is anchored tosome rigid part of the installation by means of an anchor base.The anchor base may be attached to the common connectoreither at installation or at time of manufacture.This anchorbase is an intermediate anchor and is not usually designed to1This specification is under the jurisdiction of ASTM Committee F25 on Shipsand Marine Technology and is the direct responsibility of Subcommittee F25.11 onMachinery and Piping Systems.Current edition approved Jan.1,2012.Published February 2012.DOI:10.1520/F2934-12.2Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.3Available from American Society of Mechanical Engineers(ASME),ASMEInternational Headquarters,Three Park Ave.,New York,NY 10016-5990,http:/www.asme.org.4Available from Expansion Joint Manufacturers Association(EJMA),25 NorthBroadway Tarrytown,NY 10591,http:/www.ejma.org.5Available from Pipe Fabrication Institute(PFI),511 Ave.of Americas,#601,New York,NY 10011,http:/www.pfi-institute.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 withstand the full thrust load of the piping run.The dualexpansion joint is installed in the middle of the piping run andthe thrust is directed to the middle.Each bellows acts as asingle expansion joint and absorbs the movement of the pipesection in which it is installed independently of the otherbellows.3.5 gimbal expansion jointexpansion joint designed topermit angular rotation in any plane by the use of two pairs ofhinges affixed to a common floating gimbal ring.3.5.1 DiscussionThe gimbal ring,hinges,and pins aredesigned to restrain the thrust of the expansion joint as a resultof internal pressure and extraneous forces,where applicable.3.6 hinged expansion jointexpansion joint co