1、Designation: F2934 12Standard 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, th
2、e 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
3、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 requiremen
4、ts 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
5、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
6、 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.
7、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. Termi
8、nology3.1 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 enclos
9、ure 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 t
10、he 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 joi
11、ntscan 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 atta
12、ched to the common connectoreither at installation or at time of manufacture. This anchorbase is an intermediate anchor and is not usually designed towithstand 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 th
13、e middle . Each bellows acts as asingle expansion joint and absorbs the movement of the pipesection in which it is installed independently of the otherbellows.1This specification is under the jurisdiction of ASTM Committee F25 on Shipsand Marine Technology and is the direct responsibility of Subcomm
14、ittee 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 Mechanic
15、al 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 A
16、mericas, #601,New York, NY 10011, http:/www.pfi-institute.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.5 gimbal expansion jointexpansion joint designed topermit angular rotation in any plane by the use of two pairs ofhinges
17、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 containing onebellow designed to perm
18、it angular rotation in one plane only bythe use of a pair of pins through hinge plates attached to theexpansion joint ends.3.6.1 DiscussionThe hinges and hinge pins are designedto restrain the thrust of the expansion joint as a result ofinternal pressure and extraneous forces. Hinged expansionjoints
19、 should be used in sets of two or three to functionproperly.3.7 pressure balanced expansion jointexpansion joint de-signed to absorb axial movement or lateral deflection, or both,while restraining the pressure thrust by means of tie devicesinterconnecting the flow bellows with an opposed bellows als
20、osubjected to line pressure.3.7.1 DiscussionThis type of expansion joint is usuallyintended for use where a change of direction occurs in a run ofpiping. The flow end of a pressure balanced expansion jointsometimes contains two bellows separated by a commonconnector, in which case it is called a uni
21、versal pressurebalanced expansion joint. Inline pressure balanced expansionjoints do not require a change in direction of the piping.3.8 single expansion jointsimplest form of expansionjoint, consisting of single bellows construction, designed toabsorb all movement of the pipe section in which it is
22、 installed.3.9 swing expansion jointexpansion joint designed toabsorb lateral deflection or angular rotation, or both, in oneplane.3.9.1 DiscussionPressure thrust and extraneous forces arerestrained by the use of a pair of swing bars, each of which ispinned to the expansion joint ends.3.10 universal
23、 expansion jointexpansion joint containingtwo bellows joined by a common connector for the purpose ofabsorbing any combination of axial movement, lateral deflec-tion, and angular rotation.3.10.1 DiscussionUniversal expansion joints are usuallyfurnished with control rods to distribute the movement be
24、tweenthe two bellows of the expansion joint and stabilize thecommon connector when a universal expansion joint is usedfor lateral movement only and installed at a change in directionof the piping and is intended to absorb the thermal growth ofthat section of the piping, it must be designed with tie
25、rodssuitable to absorb the full pressure thrust of the expansion joint.4. Ordering Information4.1 An expansion joint is a unique product and must bespecifically designed for the intended service. It is the respon-sibility of the piping system designer to supply sufficientengineering data necessary f
26、or the complete design. Theinformation compiled by the piping system designer must becomplete and contain all pertinent data detailing the conditionsunder which the expansion joint is expected to operate.4.2 Orders for each expansion joint shall include the fol-lowing information:4.2.1 Title, design
27、ation number, and latest revision of thisspecification.4.2.2 SizeThe nominal pipe diameter or specific ductingdiameter.4.2.3 Type of Expansion JointSingle, double, universal,guided, hinged, gimbal, swing, or pressure balanced.4.2.4 Flow Characteristics:4.2.4.1 Flow MediumIndicate whether the medium
28、is gasor liquid.4.2.4.2 Flow velocity, medium density, or viscosity, orcombination thereof.4.2.4.3 Flow direction.4.2.5 Pressure in psig (N/mm2)Design, operating, and testpressures.4.2.6 Temperate in F (C)Design, operating, and instal-lation temperatures.4.2.7 MovementAxial (extension, compression);
29、 lateral(single plane, multiplane); angular; torsional (to be avoided).Differentiate between start-up, operational, or field installationtolerance movements.4.2.8 MaterialsMaterial types (including that for the bel-lows shall be specified by the purchaser (see 5.1 for materialrestrictions).4.2.9 Int
30、ernal LinerLiner shall be specified when neededbecause of flow velocity or other flow conditions. Specificcriteria for liners is shown in Section C-3 of the EJMAStandards (see 6.6).4.2.10 External CoverTo protect personnel having closeaccess to the bellows, when thermal insulation is to be added int
31、he field, or when external mechanical damage is possible (see6.5).4.2.11 End FittingsThe type of end connections such asflanged, threaded, or others to match the mating piping orterminal equipment.4.2.12 AccessoriesSpecify what accessories are requiredand the conditions under which they operate. Con
32、sider itemssuch as insulation lugs, tie, limit, or control rods, pantographiclinkages, trunions, gimbals, drains, purge connections, anchorbases, and interplay monitoring devices.4.2.13 Dimensional LimitationsIf space limitations existspecify the maximum overall length, maximum outside diam-eter, mi
33、nimum inside diameter, and installation tolerances.4.2.14 Operating ForcesSpecify calculated bellowsspring forces and pressure thrust forces if they are required forsubsequent anchor design or other piping systems analysis. Ifthere are maximum allowable values, these must also bespecified.4.2.15 Ins
34、tallation Positionhorizontal, vertical (flow upor down). Specify if liner drainage holes are required.4.2.16 Cycle Life RequirementsSpecify an anticipatednumber of thermal cycles over the intended life of theexpansion joint.4.2.17 Testing RequirementsSpecify testing requirementsin addition to the hy
35、drostatic test required by 9.4 (for example,vacuum testing, testing at operating temperature).F2934 1224.2.18 Inspection RequirementsSpecify inspection re-quirements in addition to the inspection required by Section 9(that is, radiographic, fluorescent penetrant, or mass spectrom-eter).4.2.19 Piping
36、 Code RequirementsSpecify any piping ordesign code that must be used as the basis for design inaddition to those specified in 5.2.4.2.20 Special RequirementsSpecify the magnitude ofspecial system conditions such as vibration, shock, or hydraulicsurge. When vibration is present the customer shall pro
37、vide thenatural frequency of the equipment. The design engineer shalldesign the bellows natural frequency to be less than23 of thesystem frequency or two times greater than the system fre-quency.4.2.21 Shipping RequirementsSpecify whether specialpacking is required including protection for extended
38、outsidestorage, export handling, or special lifting considerations forheavy or large assemblies.4.2.22 Piping DrawingIn addition to specifying the aboveinformation it would be beneficial to provide a drawing of theproposed piping system.4.2.23 Supplementary RequirementsSpecify any addi-tional requir
39、ements not identified herein.4.3 Fig. 1 and Fig. 2 should be used as a guide in orderingexpansion joints to this specification.5. Materials and Manufacture5.1 Materials:5.1.1 Pressure-containing parts shall be manufactured frommaterial specifications and grades listed in ANSI B31.1. Endconnection ma
40、terials shall have in service properties similar tothe bellows material. Flanges shall meet ANSI B16.5.5.1.2 All other materials of construction shall be of the typespecified by the user and shall conform to an ASTM or ASMEmaterial specification. Materials not identified by the orderingdata shall be
41、 of the manufacturers standard and of the samequality used for the intended purpose in commercial practice.5.1.3 Materials used shall be free from defects that wouldadversely affect the performance of the expansion joint.5.1.4 All material incorporated in the work covered by thisspecification shall
42、be new. The use of rebuilt or used productsis not allowed under this specification.5.1.5 Materials for hinge or gimbal hardware, or othersliding parts, shall be chosen to minimize galling of thecontacting parts.5.2 Manufacture:5.2.1 Expansion joints shall be designed and fabricated inaccordance with
43、 requirements set forth in the ordering data andthe EJMA Standards.5.2.2 Nonstandard flanges shall be designed and fabricatedin accordance with Appendix 2 of Section VIII, Division 1, ofthe ASME Code. Flanges machined from plate shall not beused at pressures exceeding 150 psi (1034 kPa) and tempera-
44、tures exceeding 450F (232C). Hubbed flanges machinedfrom plate or bar stock shall meet the requirements ofAppendix 2, Paragraph 2-2(d) of Section VIII, Division 1, ofthe ASME Code.5.2.3 All welding shall be accomplished in accordance withANSI B31.1.5.2.4 Welding personnel and welding procedures shal
45、l bequalified in accordance with the applicable sections of SectionIX of the ASME Code.5.2.5 All fabrication details not covered by the referencedcodes and standards shall be taken from the appropriate ANSIstandard. If no standard applies, accepted industry practiceshall govern.5.2.6 The bellows sha
46、ll be of tested and proven convolutiongeometry6. Other Requirements6.1 The details of design, material supply, fabrication, andtesting of the complete product are the responsibility of themanufacturer unless specific details are requested by thepurchaser.6.2 The specified normal operating movements
47、(axial, lat-eral, and angular) shall be available concurrently. The specifiedlateral and angular movements shall be available on either sideof the expansion joint centerline.6.3 Internal sleeves, external covers, and all attached hard-ware shall be constructed so as not to interfere with adjacentpar
48、ts when the joint is in the fully deflected position.6.4 Universal expansion joints shall be designed and fabri-cated to be self-supporting and not require any externalstructure for the support of the center pipe spool piece and itscontents.6.5 Internally pressurized expansion joints to be installed
49、 insystems above 150F (66C) shall have an external cover.When external mechanical damage is possible, a cover shall befabricated to protect the joint and personnel.6.6 Internal sleeves shall be installed in internally pressur-ized expansion joints when the fluid velocity of the system,where the expansion joint is to be installed, is greater than thevalues listed in Section C-3.1 of the EJMA Standards andwhere the flow velocity exceeds 75 % of the velocity calcu-lated using Section C-3.1.4 of the EJMA Standards.7. Dimensions and Permissi
