STANDARDS OF THE EXPANSION JOINT MANUFACTURERS ASSOCIATION, INC. NINTH EDITION
EXPANSION JOINT MANUFACTURERS ASSOCIATION, INC. 25 NORTH BROADWAY, TARRYTOWN, NY 10591 RICHARD C. BYRNE, SECRETARY TEL: 914-332-0040 FAX: 914-332-1541 E-MAIL:
[email protected] www.ejma.org
STA DARDS OF THE EXPA SION JOINT MA UFACTURERS ASSOCIATION. INC. FOREWORD Since 195 . when the Expansion Joint Manufacturer"s Association (EJMATM) first published these Slandards. continuing technological improvements in the application and design of Expansion Joints h,:lVC been reported through the coopcratin' efforts of its association members by expanding the scope and content of this publication. Founded three years earlier in 1955. the Expansion Joint Manufacturer"s Association began with a group of companies experienced in the application. design. and fabrication of Expansion Joims. The first EJfvtA™ Standard edition was. of necessity. somewhat brief and covered only applications involving ax.ial movement BUl as research and extensive testing results were catalogued. morc detailed design data has been included in the EJMA HI Standard. The EJMA ™ Standards are intended for 3pplieation to metallic bellows expansion joints having only the convolution shapes shown in the Standards and having convolution 'velds only in the meridional direction with the exception of the bellows attachment welds. The EJMATM Teehnic::!l Committec is dedicated 10 continuously improving the utility and technical content of the Standards. Suggestions and comments from industry users arc welcomed and should he fOl"\varded to the Secretary of this Association in writing. It is imponant to notc that the EJMATM Standard is a trade association document containing recommcndations for application of expansion joint products and in-depth Icchnical infomlation for use in designing expansion joint products. It is not a manufacturing standard or a quality assurance document. The type of llon-destructive examination and the extent ofqualiry assurance testing to be applied to given product should be addressed by other documents such as the ASME B31.3 Piping Code. the ASME Pressure Vessel Code or another user provided specification. The Standard docs not limit or dictate the manufacturing process to be used for construction of expansion joints. nor docs it establish specific engineering requirements deemed nccessary for thc safe application. design and manufacture of Expansion Joints. Ifthcre is a strong preference for a cenain type of manufacturing process. the user should provide this infonnation. Industry users arc cautioned that these Standards should not be considered as a design handbook. and must not replace sound engineering judgment. education and experience.
As of this writing. the EJMA ™ Standard thoroughly covcrs the design of expansion joint bellows clements. Howcver. the Standard docs not cover the design of hardware associated with restraint of pressure thrust. Prcssurc thrust rcstraint h: to obtain the most efficient service from Expansion Joint installations. These Standards are based upon sound enginecring principles. research and field experience in the manufacture. design. installation and use of Expansion Joints. These Standards may be subject to revision as further invcstigation or expericnce may show is necessary or desirable. Utilization of these Standards remains entirely optional. Nothing herein shall constitute a warranty of any kind. expressed or implied. Accordingly. all warranties of" hatc' cr nature. expressed or implied. arc herewith specifically disclaimed and disavowed.
Copyright 1958, 1962, 1969, 1975, 1976, 1980, 1985, 1993, 1998, 2003, 2005. 2008 EXPANSION JOINT MANUFACTURERS ASSOCIATION. INC. All rights reserved. This book or any part thereof may not be reproduced in any fon11 without written penllls~ion of the Expansion Joint Manufacturcrs Association. Inc. The specification shects constituting Appendix A 3rc 1101 covered by any copyright restrictions and may be freely reproduced and utilized by purchasers of this Standards manual.
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\ Expansion Joint Manufacturers Association. Inc.
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STA DARDS OFTHE EXPANSION JOINT MANUFACTURERS ASSOCIATION. INC.
~IEMBERSHIP LIST
EXPANSION JOL'\'T L-I.NUFACTURERS ASSOCIATION. H'C.
American BOA. Inc. - Cumming. GA Badger Industries. Inc. - Zelienople. PA Expansion Joint Systems. inc. - Santee. CA FJexider S.r.I.- Torino. Italy Hyspan Precision Products. loc.- Chula Vista. CA Idrosapiens. 5.r.l- Leini (Torino), Italy
Microflex - Omond Beach. FL Senior Flexonics. Inc.. Pathway Division - New Braunfels. TX
SFZ - Lyon. France U.S. Bellows. Inc. - Houston. TX WahlcoMetroflex. Il1c.- Lewis[QI1. ME \'"It"Leomann. GmbH - Pforzheirn. Genmmy
CURRENT TECHNICAL COMMITTEE MEMBERS EXPANSION JOI T MANUFACTURERS ASSOCIATION. I
'c.
Patrick Vainio· American BOA. Inc.
Jack Hanna - Badger Industries. Inc. Mike Cabrera - Expansion Joint Systems. Inc. Mana Nivoli - Flexlder S.r.l.- Torino. Ital) COli Sleimar - Hyspan Precision Products. Inc. AOilio Pietrafesa - Idrosapiens. S.r.1 Jeff DePJero - Microflex
Bob Broyles - Senior Flexonics. Inc.. Pathway Dlyision
Max Micheni - SFZ Roy Felkner· u.S. Bellows. Inc. Rick Marcoue- WahleoMetroflex. Inc. Peter Berger - \\"itzenmann. GmbH
E.xpafbion Joml Manufaclurer:-> AS:>OClatlon. Inc
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STA DARDS OFTHE EXPA, SION JOI T MANUFACTURERS ASSOCIATION, INC.
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STANDARDS OF THE EXPANSION JOINT MANUFACTURERS ASSOCIATION. INC.
COi\'TE:\'TS Page
Section
ii
Foreword i\lembel'"ship of EJ"'IA.
iii
Current Technical Comnlitte{' i\lenlbers
iii
SECTiON 1 - SCOPE. DEFINITIOl'S. AND NOMENCLATURE 1.1
Scope .....................•..........................•.............................................................................................................•.....
)·1
1.2
IJefinitiolls.............................................................................................................................................................
I-I
1.3
Nonlt'nclaturt'
1-6
SECTION 2 - SELECTIO:-; AND APPLICATIONS 2.1 2.2 2.3 2...1 2.5 2.6 2.7 2.8 2.9 2.10
Selection of Expllnsion Joints St'Il'1:tion for Axial J\'lo\·t'ment Selection ror Lateral Deflection. Angular Rotation. & Combined Applications Using Singlt' Expansion Joints Applications Using Uni"ersal Expansion Joints Applications Using Pressure Balanced Expansion Joints Applications Using Hingt'd E:.\:pansion Joints Calculation or Angular Rotation in a 3 "'inge Piping S~'stem Applications L"sing Gimbal Expansion Joints Anchor. Guidt', and SUPI)Orl Requircnu"nls
SECTION 3 - SAFETY 3.1 3.2 3.3 304 3.5 3.6 3.7
l\Ion~ments
2-1 2-2 2-5 2-6 2-8 2-12
2-15 2-20 2-22 2-23
RECOM~IENDATIONS FOR
PIPING SYSTEMS CONTAINING BELLOWS EXPANSION JOINTS
Design Specification Expansion Joint Design Expansion Joint l\-lanuracturing Qualit)· Installation Post Installation Inspection Prior to S~stcm Pressure Test Inspection During and Immediatcl~ Afler S~ stem Pressure Tests Periodic In-Sen ice Inspection
3-1 3-3 3-3 3-3 3-4 3--4 3-5
SECTION 4 - CIRCULAR EXPAliSIO:-l JOINT DESIGN -1.1 -1.2 -1.3 -1...1 -1.5
-1.6 -1.7 -1.8
l\'IO\enlent Equalions........................................................................................................................................... Combining l\'lo\'emt'nts I\lo\"enlent Range Unhersal Circular E:\pansion Joint I\lo\'ements Cold Springing or Circular Expansion Joints -1.5.1 Force Reduction -1.5.2 Slabilit) -1.5.3 Component Clearanct's Forces and l\lonlents -1.6.1 Force and l\lonlcnt Calculation l\laximulII A\:ial Compression Based On Instabilil~ Expansion Joint Flange Loading Considerations
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Expan!>ion Joml Manufacturers
A~sociation.
Inc.
-1-1 -1-2 -1-3 -1-5 -1-5 -1-5 -1-5 -1-6 -1-6 -1-6 -1-10 -1-10
SECTION 4 - CIRCULAR EXPANSIO:-l JOI:-IT DESIGN (continucd) 4.9
"ibr3rion ...............................................••........_.................................................................................................... -1.9.1 Single Bellow!! -1.9.2 Dual Bl"lIows (Universal t:xpamiion Joint) _......................................•........_......... -1.10 Inlernal Slee\'es - Circular E:\"pansion Joinl5 ....•.......•...................................................................................... ~.IO.I Crileria for Determining The ~et'd for Internal SIf('\es ..........................................................•............ ~.10.2 Design Rl"Commendations for Internal Slee\'('s ................•......••...•...••.........•.....•.....•.•.....•..••................. -&.11 External Co\·t'rs - Circular Expansion JoinTs.................................................................................................... ~.12 Uello\\s Design ~.12.1 Paramelers and Criteria Affl"Cling 8ellows Design 4.12.1.1 Unreinforced 8('llo\\s ...................•................•.......•.........•..............•................................................. 4.12.1.2 Reinforced Bellows 4.12.1.3 Inlernal Pressure Capacity ~.12.1.4 Deflection Stress 4.12.1.5 Fatigue Life E."peclanc~' 4.12.1.6
Bello\\sStabilit~
4-11 4-1 I -1-13 4-14 4-14 4·16 4-17 -&-18
4-19 -&-19
4-19 4·20 4-20 4-21 4-23
4.12.1.7 Bello\\s Spring Ratl' 4.12.1.8 Correlation Tesling 4.12.1.9 Bellows Heal Treatnlenl ..................................................•...................•........................................... ~.13 Design Equations -1.13.1 Design Equations for nreinforcl'd Bellows _......................... -&.13.2 Design Equations for Reinforced 8ello,,'S ......•...................................................................................... -&.13.3 Design'EquaTions for Toroidal Bello"'s -&.13.-& Bellows Torsion - Unreinforced/Reinforced 8('1I0\\s 4.1-& Bcnchrnark Calculalions _......................................................... -&.15 Effl"C1 of E.\lernall)rellsure
4·26 -&-27
4-27 4-28 4-28 4-30 4-32 -4-33 -4-3-1
4--&2
SECTION 5 - RECTANCULAR EXrANSION JOINT DESICN 5.1
5.2 5.3 5.-& 5.5
Equations COlllbining 1\10\'Cn1('I1Ts i\IO\'l'llIent Range Force and l\lolllel11 Calculalions Dt'sign Equations
SECTION 6-QUALITY ASSURANCE AND BELLOWS 6.1 6.2 6.3 6.4
6.5 6.6 6.7 6.8 6.9 6.10 6.11 6.12 6.13 6.1-& 6.15
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~Iovt"lnent
C Expansion Join! Manufacturers Association. Inc.
5-4 5-5
FOR~IING ~IETHODS
and R~ponsibilit~ Assurance Organization Drawings. Design Calculalions. and Specification Control .......•.._.•................._ l\lateri3ls :lnd l\13ter-ia.!s Control l\lanufacluring Process Control In-Process Inspection and Exantination Progrant 1'1t'lisuring a.nd Test Equipmt'nt Control l\lalt'rial Non-conforntaltce Conlrol Corrective ACTion (Supplies and St'n'it't's) \\'elding H('at Treatrtlt'nt I'llckaging. Presen·ation. Shipping and Slorage , Custoltler QualiT~' Assurance Audits Records Rt'tenlion Qualil·~
54
5-6
Gt'nt'ral AUlhoril~
5-1
. . . . .. .. . .. .. .. . . . .. . wW'.\'
6-1 6-1 6-1 6-1 6-2 6-2 6-2 6-3 6-3
6-3 6-3 6-3 6-3 6-4 6-4
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STANDARDS OF THE EXPANSIO 'JOINT MANUFACTURERS ASSOCIATION. INC. SECTIOJ" 6 - QUALITY
ASSURA~CE AND
BELLOWS FORMING I\'IETHODS (continued)
6.16 !\'Ielhods of Fornling "Ietal Bellons 6.16.1 El:tstonlcric Fornling 6.16.2 Expansion ([~pandillg l\lulldr{'l) Forming 6.16.3 Hydraulic Fornling 6.16.4 Pneunlalic Tube rorTlling 6.16.5 Rolled Con\'oluted Shel.'t 6.16.6 Roll Forming 6.16.7 Rolled Ring 6.16.8 Press-Brake Forlliing ,................................................................................................ 6.16.9 Combined Forming 6. t 7 rabrication Tolerances
64 64 6·5 6-5 6-6 6-6 6-7 6-7 6-8 6-8 6-9
SECTION 7 - EXA1\,IINATION AND TESTINC 7.1
7.2 7.3
~on-destructh'e Exanlinalion 7.1.1 Radiographic Exalllillation 7.1.2 liquid PenetJ"anl Examination 7.1.3 Fluorescent PenetJ"ant Examination 7.1..1 l\'lllgnetic PaJ"ticie Examination 7.1.5 Ultrasonic EXllnlination 7.1.6 Halogen leak Examination 7.1.7 i\lass SpcctJ"ollu·ter ExanlinilliOIl 7.1.8 A.ir Jet leak EX31ninaiion Non-destructh'e Testing 7.2.1 PJ"essure Testing Deslructivl.' Testing 7.).1 Fatigue life Testing 7.3.2 SCluirm Testing 7.3.3 l\leJ"idional Vielil-RuptuJ"e Testing
7-1 7-1 7-1 7-2 7-2 7-2 7-2 7-3 7-3 7-) 7-) 7-'7-'7-4 7-5
SECTION 8 - SHIPPINC AND INSTALLATION 8.1 8.2 8.3 8..1 8.5
\\ \'v\\
Shipping Tags Shipping DC'\ices Installation Gaskets Reconlnlended Inslallation Instructions
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E.~pansion
8-1 8-1 8-2 8-2 8-3
JOIllI Manufacturers As:.ociallon. Inc.
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SECfION 9 - FEATURES. ACCESSORIES. A!'(D 9.1
~Iulli-rlr Be!.lows ........................................................................................................................•................••..... 9.1.1 Multi-PI~' Conslruclioll "jth the Same Total Thickness as .a Single PI~' COlIslruclion 9.1.1.1 Pressur('Capaci~ _...........................................................
9.1.1.2
9.2
9.3 9.4
\ iii
~IATERIALS
Fal.igut' Lift.'
9.1.1.3 Spring forces 9.1.IA Bellows Stability 9.1.2 l\1ulli.Ply Construction nith the Same Thickness for Each PI~' as a Single Ply ConSlruclion 9.1.2.1 Pressure Capacit~' 9.1.2.2 Fatigue Life .•.........•.....•.•....................•..•.......•....•.............................................................................. 9.1.2.3 Spring forces ................................................................................................................•................... 9.1.2.4 Bt'llows Stability ......................................................................................................•........................ 9.1.3 Mulli-Ply Conslruction nilh Greater Thickness for Ench PI~ Than for Single PI~' Construction 9.1.3.1 Pressure Capld.ci~' 9.1.3.2 fatigul' Life ............................................................................................................•..•................•...... 9.1.3.3 Spring forct's 9.1.JA Bellows Stability 9.IA l\lulliple l\lateria.1 Usage .............................................................................•.•...•••...•.........•.....•.....••........ 9.1.5 Redundant PI~' Construction with the Samt' Thickness for Each PI~ as a Single Ply Construction 9.1.5.1 Pressure Capacit)· ................................................................................•............................................ 9.1.5.2 fatigue Life ................................................................•................•......••...•.....................•.....•...........•. 9.1.5.J Spring forct'S ...........................................................................................................•........................ 9.1.5A Bellows Stabilit~' ......•...••.....•....•...................•.................................................................................... 9.1.5.5 l\lonil'ored Ply Be-lions ....................••...•..•......••.•.......••.......•.•••......................................................... Til' Rods, Hinges and Similar Accessories 9.1.1 forces and Loads ...........................•......................................................................................................... 9.2.2 l\1l'thods of Attachment ..............................................................•............................••.....................•...•••.. 9.1.3 I)esign Consideration 9.1.3.1 Tic Rods. Hinges. and Gimbals ...................•..•................................................................................ 9.1.3.2 AttachnH~nlS tn Piping 9.2.3.3 Component Design Stress Limits 9.2 ..1.4 References flanges .........................................................................................................................•...........•..•.••...................... Corrosion
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Expansion Join! Manuf.1clUref" A..socialion. lne
9·) 9-1 9-1 9-1 9-1 9-1 9·1 9-1 9-1 9·1 9·1 9-2 9-2 9·2 9-1 9-2 9·2 9-3 9-3 9·3 9·3 9-3 9-3 9~ 9~
94 9-4 9-4 9-5 9-5 9-12 9·13 9-14
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STANDARDS OF THE EXPANSION JOINT MANUFACTURERS ASSOCIATION, INC
APPENDICES Appendix Appendix Appendix Appendix Appendix Appcndh Appendix Appendh: Appendix
A 8 C 0 [ r G U I
Standard Expansion Joint Specification Sheets Key to Symbols Used Circular and Rectangular l\lon·ment. Force and Moment [(Illations COII\'eTsion Factors and Rderences Preparation of Technical Inquiries BeIlOl'S Fatigue Tt'st Requiremellts BelJo\\s High Temperature C~c1e LifeAngular Rotation About Ont' End Tabulatl.'d V:lllles for Cp • C/. e,l' BI , B:. and B J
Appendix J
Examples
Round Expansion Joints. Forces. and l\lo\'enu.>nls.......................................................................................
J·I
I Single Expansion Joint subjected 10 axial mo\ ement I Single EXp:ulsion Joint subjected 10 axial and I:ueral mOHllIent 3 Single Expansion Joint with tie rods subjected 10 axial and laleral movement...................................... 4 Tied Universal Expansion Joinl subjected to lateral mO\'ell1enl in two plant's....................................... 5 Universal pressure balanced Expansion Joint located between two pieces of equipment with movements at end points........................................................................ 6 Single Expansion Joinl. allached to \"essel nozzle. subjected 10 :lxial and lateral movement 7 Calculation of Angular ROlation in a 3 hinge piping system.................................................................... 8 Three (3) hinge Expansion Joint s~stenl 9 Bellows [qui\ all'nt Movement I)er COIn olution 10 Rectangular Expansion Joint ~10\enlellts ;......... II Calculation for a Straight Run of Pipe Containing lUI A:\ial Expamion Joint
J-l J-4 J-7 J-IO J-I-I J·19 J-23 J·25 J-28 J-31 J-35
TABLES Table Table Table Table Table
I II III
IV \'
Recommended Idl'ntilicalion Dala Required for Bello\\s subjected to Destructive Tests Conlponent Design Stress L.ilnits , Shape Factors , Thermal E:\p:tnsion of Pipe in Inches per 100 feet Moduli of Elasticil) or Commonl) Used Bello\\s Materials
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7-6 9-6
9-8 0-12 0-101
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STANDARDS OF THE EXPANSION JOINT MANUFACTURERS ASSOCIATION. INC. SECTlOI\" I - SCOPE. DEFINITIONS. AI\"D
I\"O~IENCLATURE
1.1 SCOPE
The EJMA T\I Standards arc only intended for application to metallic bellows expansion joints.
1.2 DEFINITlOI\" OF TERMS The Expansion Joint Manufacturers Association. Inc. has adopted the following definitions of Expansion Joint components and related equipment AI\"GULAR ROTA TlOI\" The displacement of the longitudinal axis of the Expansion Joint from its initial straight line position inlo a circular arc. Angular rotation is occasionally referred to as "rotalional movement." This is 1101 torsional rotation which is described funher in this section.
AXIAL CO~IPRESSION The dimensional shonening of an Expansion Joint along its longitudinal axis. Axial compression has been referred to as axial mo\'emenl. tra\erse or compression. AX.lAL EXTE 'SIOI\" The dimensional lengthening of an Expansion Joint along its longitudinal axis. Axial extension has been referred (0 as axial movement. traverse. elongation or extension.
BELLOWS The flexible element of an Expansion Joint consisl1ng of one or more convolutions and the end tangents \\-ith L" D,,::;; 3. with no more than five plies. CONTROL RODS Devices. usually in the fonn of rods or bars. anached to the Expansion Joint assembly whose primary function is to distribute the movement between the two bellows of a universal Expansion Joint Control rods arc not designed to restrain bellows pressure thrust CONVOLUTION The smallest flexible unit ofa bellows. The total movement capacity ofa bellows is proportional to the number of convolutions. COVER A deyice used to provide limited protection of the exterior surface of the bellows of an expansion jomt from foreign objects or mechanical damage. A cover is some limes referred 10 as a shroud. DIRECTlOI\AL ANCHOR A directional or sliding anchor is one which IS designed 10 absorb loadmg in ODe direction while pemlming mOlion in another. It may be either a main or intennedl3te anchor. depending upon the application m\'oh'ed. When designed for the purpose. a directional anchor may also function as a pipe alignment gUlde.ln the design ofa directIOnal anchor. an effort should be made to minimize the friction between its moving or slidm£ parts. smce this will reduce the loading on the piping and equipment and insure proper functioning of me anchor.
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STANDARDS OF THE EXPANSION JOINT MANUFACTURERS ASSOCIATION. INC. SECTION 2- SELECTION AND APPLICA TlONS 2.1
SELECTION OF EXPANSION JOINTS
The first step in the selection of Expansion Joints is to choose tentative locations for the pipe anchors. Any piping system. regardless of its complexity. can be divided into a number of individual expanding pipe sections having relatively simple configurations (ie: straight fUllS. "L" shaped bends. "2" shaped bends and other means). by means of anchors. The number of pipe anchors selected. as well as their locations. will depend upon the piping configuration. the amount of expansion which can be accommodated by a single Expansion Joint. the availability ofsrructural members suitable for use as anchors. the location of various pipe finings. the location of connected equipment. the location of branch connections and other considerations. The major pieces of connected equipmem such as turbines. pumps. compressors. heat exchangers. reactors. and similar devices can be considered as anchors in most applications. It is usually necessary to supplement these equipment anchor points by locating additional anchors at valves. at changes in the direction of the pipe. at blind ends of pipe and at major branch connections. It is generally advisable to start out with the assumption that the use of single and double Expansion Joints in straight axial movement will provide the simplest and most economical layout. unless there are obvious advanrages to be gained frolll another approach. After the anchor points have been tentatively located. the resulting pipe configurations should be reviewed to deternline whether they conform 10 the standard pipe sections shown in Sections 2.2 and 2.10. At this point. consideralion should be given to the relative merits of systems utilizing single and double Expansion Joints for axial movement only. as opposed to those.utilizing universal. pressure balanced. hinged and gimbal Expansion Joints. A final decision on anchor locations and the types of Expansion Joints to be used can only be made after a comparison of various alternative solutions. Cost. the ability 10 comply with cyclic life and force requirements. space restrictions. and similar items should be considered. The next step is 10 calculate the actual change in length of each leg of each individual pipe seclion due to temperature changes. The minimum and installation temperatures are assumed to be 70° F unless otherwise specified. An allowance. added by the system designer, should tben be included in the actual calculated movements to account for the following possibilities: (a) The minimum and/or installation temperatures used in the design calculations may have been based on the erroneous assumption that the metal temperature of the pipe is the same as the ambient temperature. (b) During erection of the piping. it may be necessary to relocate some of the anchor points because of construction problems encountered at the job site. (c) During operation the system may be subject to a different temperature range than the designer anticipated. panicularly during stan-up. Refer to Appendix J Example II for a sample calculation.
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2-1
STANDARDS OF THE EXPANSION JOINT MANUFACTURERS ASSOCIATION. INC. SECTION 3 - SAFETY
RECOM~IENDATlONS
FOR PI PING SYSTEMS CONTAINING BELLOWS EXPANSION JOlNTS
Bellows Expansion Joints are employed in piping systems to absorb differential thennal expansion while containing the system pressure. They are being sliccessfully utilized in refineries. chemical plants. fossil and nuclear power systems. heating and cooling systems. and cryogenic plants. Typical service conditions have pressures ranging from full vacuul1110 1000 psig and temperatures from -420 OF to 1800 OF. Such Expansion Joints fall info the category of a highly engineered product. The system operating characteristics. the Expansion Joint design and manufacturing quality. and the installatioll. test and operating procedures must all be considered for all Expansion Joint installations. Unlike most commonly used piping components. a bellows is constmcted of relatively thin gage material in order to provide the flexibility needed to absorb mechanical and thennal movements expected in service. This requires design. manufacturing quality. handling. installation and inspection procedures which recognize the unique nature of the product In general. the most reliable and safe bellows Expansion Joint installations have always involved a high de!,rree of understanding between the user and manufacturer. With this basic concept in mind. this section was prepared in order to betler inform the user of tbose factors which many years of experience have shown to be essential for the successful installation and perfonnance of piping systems containing bellows Expansion Joints. Additional detailed infomlation can be found in other sections of these Standards. 3.1 DESIGN SPECIFICATION A. A design specification shall be prepared for each Expansion Joint application. B. In preparing the Expansion Joint design specification it is imperative that the system designer complelely review the piping system layout. flowing medium. pressure, temperature, and movements. The standard Expansion Joint Specification Sheets published in Appendix A can be used as a guide. Particular attention shall be given to the following items: a. The piping system shall be reviewed to detemline the location and type of Expansion Joint most suitable for the application. The EJMA Standards provide numerous examples to assist tbe user in this effort. The availability of supporting structures for anchoring and guiding of the line, and the direction and magnitude of themlal movements to be absorbed will have a definite bearing on the type and location of the Expansion Joint. TORSIONAL ROTATION OF THE BELLOWS SHOULD BE AVOIDED. Where torsional rotation cannot be avoided. refer to Section -t 13.4. b.The bellows material shall be specified and must be compatible with the flowing medium. the external environment and the operating temperarure. Particular consideration shall be given [0 possible corrosion including stress corrosion. The 300 series stainless steels may be subject to chloride ion stress corrosion. High nickel alloys are subject to caustic induced stress corrosion. The presence of sulfur may also be detrimental to such nickel alloys. The material chosen shall also be compatible with any water treatment or pipeline cleaning chemicals. In some cases. leachates from insulating materials can be a source of corrosion. c. Internal sleeves shall be specified in all applications invohing flow \'elocities which could induce resonant vibration in the bellows or cause erosion of the convolutions resulting in substantially reduced bellows life. See Section 4.9. d. The system design pressure and test pressure shall be specified realistically without adding arbitrary safety factors. Excess bellows material thickness required for overstated www.eJma.org
(, Expansion Joint Manufacturers Association. Inc.
3-1
STANDARDS DF THE EXPANSION JOINT MANUFACTURERS ASSOCIATION. INC. SECTION 4 - CIRCULAR EXPANSION JOINT DESIGN 4.1
MO\'E~IENT EQUATIONS Expansion Joints may be subjected to axial movement. angular rotatioll. lateral deflection. or any combination of these. Figure ..L2 shows a single bellows Expansion Joint subjected to axial movement only. Note that the total applied movement is absorbed by a unifonn displacement of al1 the convolutions. This also applies to dual bellows assemblies such as universal. swing and universal pressure balanced Expansion Joints.
e.,
x
= N
x e =, 2N
(For a 'single bellows Expansion Joint)
(4-1 )
(For a dual bellows Expansion Joint)
(4-2)
In equation (4-2) above. the value of-r should include the thennal expansion of the center pipe nipple connecting the two bellows. This may be a significant factor in applications involving long cemcr pipe nipples. or a large differential between rhe minimum and maximum design temperatures. When the center pipe nipple is anchored. as it is in a double Expansion Joint (see Section 1.2). each eod of the assembly should be treated as a single Expansion Joint. In such a case. equation (4-1) will apply and the value ofx should include the (hennal expansion ofthat p'onion of the center pipe nipple which is located between the anchor base and the bellows in question. Figure 4.3 illustrates that an Expansion .Ioint bellows absorbs pure angular rotation by extending uniformly on one side and compressing unifornlly on the other. The movement of any convolution may be cxpressed as:
eD
e, =--" 2N
(For a single bellows Expansion Joint)
(4-3)
e = ODm u 4N
(For a dual bellows Expansion Joint)
(4-4)
As illustrated in figures 4.4 and 4.5. lateral deflection of an Expansion Joint is, in reality. a special case of angular rotation. The two bellows in a universal type Expansion Joint. or each end oflhe bellows ofa single type Expansion Joint. rotate in opposite directions to produce the total lateral deflectiony. Unlike the case of pore angular rotation. lateral deflection results in unequal movement distribution over the bellows. the amount of displacement increasing with the distance from the center of the Expansion Joint. This applies to both single and universal type Expansion Joints. Since we are concerned only with the maximum displacement per convolUlion which may be imposed upon any convolution in the Expansion JOIllt. the following equations are arranged to arrive at the maximum displacement figure. For universal Expansion Joints. a factor K" is introduced which is a function of the ratio of the total distance between the OUlemlost ends of the elements to the convoluted length of the Expansion Joint. The value of K" for any given ratio of L" 2L~ may be found in figure 4.1 and the displacement per convolution resulting from applied lateral deflectiony. is as follows:
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(' Expansion Joint Manufacturers Association. Inc.
4-1
STANDARDS OF THE EXPANSION JOINT MANUFACTURERS ASSOCIATION. INC. SECTION 5 - RECTANGULAR EXPANSION JOINT DESIGN
The following sections describe the various movements. forces. and moments which occur at the interface ofrectangular bellows and the associated dueling system. The movements arc identical in all respects to those imposed on circular expansion joinrs and are defined in Section 1.2 of these standards. Further. the method of analysis ofdetemlining forces and moments resulting from these movements is also identical 10 circular bellows. Therefore. the same nomenclature can be used. with the exception thaI [he lemlS L1 and L, (mean length oflong or short sides) is substituted for D 1/1 (mean diameter). The summary of equations which follows is the rectangular counterpart of the circular bellows. The explanation for the use of these equations is found in Section 4.6.1. 5.1
MOVEIVLENT EQUATIONS Rectangular Expansion Joints may be subjected to axial movement angular movement. lateral detleclion or any combination of these. 3.
Axial movement for single bellows Expansion Joint x N
(5-1)
e~
,
b.
c.
Axial movement for universal bellows Expansion Joints. x e =-, 2N
(5-2)
Equivalent axial movement per convolution for single or universal bellows with angular rotation.
r L,,,c..
L,-_
8,
(5-3 )
SINGLE BELLOWS FIGURE 5.1
r
L,-e
til
8,L
I =-4N
(5-4)
UNIVERSAL BELLOWS FIGURE 5.2
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c Expansion Join! Manufaclurers Associalion. lnc.
5-1
STANDARDS OF THE EXPANSION JOINT MANUFACTURERS ASSOCIATION. INC. SECTION 6 - QUALITY ASSURANCE AND BELLOWS FORMING METHODS
This section describes the minimum quality control program requirements for a manufacrurer of metallic bellows type expansion joints inclusive of the product design and compliance [0 customer specifications. These requirements pertain to the inspections and tests necessary to substantiate product conformance to drawings. specifications and contract requirements. The program shall assure systematic and adequate quality control throughout all areas of contract perfOml
