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www.flexonics.com1 800 854 2553Senior Flexonics Pathway2400 Longhorn Industrial Dr.New Braunfels, Texas 78130Tel Int: 1 830 629 8080Fax Int: 1 830 629 6899E-mail: [email protected] Flexonics Pathway115 Franklin RoadOak Ridge, Tennessee 37830Tel Int: 1 865 483 7444Fax Int: 1 865 482 5600

ContentsIntroduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Expansion Joint Design Basics . . . . . . . . . . . . . . . . . . . 2Applications Engineering . . . . . . . . . . . . . . . . . . . . . . . 5Joint Product Selection Guide . . . . . . . . . . . . . . . . . . . 7Mid-Corr Expansion Joints. . . . . . . . . . . . . . . . . . . . . . 8Free Flexing Expansion Joints . . . . . . . . . . . . . . . . . . 13Controlled Flexing Expansion Joints . . . . . . . . . . . . . 15Externally Pressurized Expansion Joints. . . . . . . . . . . 18Expansion Compensators. . . . . . . . . . . . . . . . . . . . . . 19PR/SVC Engineering & Installation Data . . . . . . . . . . 20Pressure Relief/Safety Valve Connectors . . . . . . . . . . . 22Flexible Metal Pump Connectors . . . . . . . . . . . . . . . . 24Non-Metallic Expansion Joints . . . . . . . . . . . . . . . . . 26Exhaust Flexible Connectors . . . . . . . . . . . . . . . . . . . 28Flange Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30Engineering Information . . . . . . . . . . . . . . . . . . . . . . 31Pipe Alignment Guides . . . . . . . . . . . . . . . . . . . . . . . 32Intermediate Guide Spacing Chart. . . . . . . . . . . . . . . 33Installation Instructions . . . . . . . . . . . . . . . . . . . . . . . 34Warranty Information . . . . . . . . . . . . . . . . . . . . . . . . 36

IntroductionWith origins dating to 1902, Senior Flexonics Pathwayis today recognized as the leader in the metalexpansion joint industry. Our leadership has beenearned through consistent application of solidengineering principles, stringent quality standards andproduct innovation to produce safe and reliable metalexpansion joints and flexible connectors for bothindustrial and HVAC piping and ducting applications.This catalog contains product performance data andphysical descriptions for each of our light industrialand HVAC expansion joint and pipe guide products.In addition, applications engineering information isincluded which describes the recommended practicesfor using these expansion joints in your piping system.Hopefully, you will find this catalog to be a useful andinformative technical reference manual that assists youin making an educated selection of the most suitableproducts for your application.NOTICE: The information and technical data containedherein is believed to be accurate and the best informationavailable to us at the time of printing this catalog. Allinformation and data contained herein is subject to changeat any time, without notice. Because we have no control overthe selection, installation or use of our products, we cannotbe responsible for their improper application or misuse.1

-––[EXPANSION JOINT DESIGN BASICS ]–-–Piping FlexibilityAll materials expand and contract with thermal change. In the case of piping systems, this dimensional change canproduce excessive stresses throughout the piping system and at fixed points such as vessels and rotating equipment, aswell as within the piping itself.Pipe loops may add the required flexibility to a piping systemif space permits, however the initial cost of the additional pipe,elbows and supports must be considered. In addition, increasedcontinuous operating costs due to pressure drop may result fromthe frictional resistance of the flowing media through additionalelbows and pipe. In some cases, pipe diameter must be increasedto compensate for losses due to pressure drop.A practical and cost effective means of achieving piping systemflexibility in a compact design is through the application of expansionjoints. The most efficient piping system is the shortest and mostdirectly routed system and expansion joints make this possible.Expansion joints provide an excellent solution for isolation of settlement, seismic deflection, mechanical vibration andsound attenuation transmission produced by rotating equipment.Design BasicsMetal bellows expansion joints consist of a flexible bellows element, appropriate end fittings such as flanges orbutt-weld ends to allow connection to the adjacent piping or equipment, and other accessory items that may berequired for a particular service application.BELLOWS DESIGNBellows are manufactured from relatively thin-walled tubing to form acorrugated cylinder. The corrugations, commonly referred to as convolutions,add the structural reinforcement necessary for the thin-wall material to containsystem pressure. The bellows designer selects the thickness and convolutiongeometry to produce a bellows design that approaches, and often exceeds thecapacity of the adjoining pipe to contain system pressure at the specifieddesign temperature.Flexibility of the bellows is achieved through bending of the convolution sidewalls, as well as flexing within their crestand root radii. In most cases, multiple convolutions are required to provide sufficient flexibility to accommodate theexpected expansion and contraction of the piping system.2

MOVEMENT CAPABILITIESAxial Compression: Reduction of the bellows length dueto piping expansion.Lateral Offset: Transverse motion which is perpendicularto the plane of the pipe with the expansion joint endsremaining parallel.Axial Extension: Increase of the bellows length due topipe contraction.Angular Rotation: Bending about the longitudinalcenterline of the expansion joint.Torsion: Twisting about the longitudinal axis of the expansion joint can reduce bellows life or cause expansion jointfailure and should be avoided. Expansion joints should not be located at any point in a piping system that wouldimpose torque to the expansion joint as a result of thermal change or settlement.CYCLE LIFEIn most applications, design movements cause the individual convolutions to deflect beyond their elastic limits,producing fatigue due to plastic deformation, or yielding. One movement cycle occurs each time the expansion jointdeflects from the installed length, to the operating temperature length, and then back again to the original installationlength.In the majority of applications, total shutdowns are infrequent, therefore a bellows with a predicted cycle life of oneor two thousand cycles is usually sufficient to provide reliable fatigue life for decades of normal service. High cycle lifedesigns may be desirable for service applications that include frequent start up/shut down cycles.The bellows designer considers such design variables as material type, wall thickness, the number of convolutions andtheir geometry to produce a reliable design for the intended service with a suitable cycle life expectancy.SQUIRMAn internally pressurized bellows behaves in a manner similar to that of a slender column under compressive load.At some critical end load, the column will buckle, and in a similar manner, at a sufficient pressure, an internallypressurized bellows that is installed between fixed points will also buckle, or squirm.3

Bellows squirm is characterized by a gross lateral shift of the convolutions off of thelongitudinal centerline. Bellows squirm can reduce cycle life, or in extreme cases, producea catastrophic failure.To avoid squirm, the bellows designer must limit movement capacity and flexibility to a levelthat insures that the bellows retains a conservative margin of column stability beyond therequired design pressure.END FITTINGSExpansion joints will include appropriate end fittings such as flanges or butt-weld ends thatshould match the dimensional requirements and materials of the adjoining pipe, or equipment.Small diameter compensators are available with threaded male ends, butt weld ends or coppersweat ends. Threaded flanges may be added to the threaded end compensators if a flangedconnection is preferred.ACCESSORIESFlow liners are installed in the inlet bore of the expansion joint to protectthe bellows from erosion damage due to an abrasive media or resonantvibration due to turbulent flow or velocities which exceed: For air, steam and other gasesa) Up to 6” dia.- 4 ft./sec./inch of diameterb) Above 6” dia. -25 ft/secFor water and other liquidsa) Up to 6” dia. - 2 ft./sec./inch of diameterb) Above 6” dia. -10 ft./sec.Expansion joints that are installed within ten pipe diameters downstream of elbows, tees, valves or cyclonic devicesshould be considered to be subject to flow turbulence. The actual flow velocity should be multiplied by 4 to determineif a liner is required per the above guidelines. Actual or factored flow velocities should always be include with designdata, particularly flow that exceeds 100 ft./sec. which require heavy gauge liners.External Covers are mounted at one end of the expansion joint, providing a protective shield that spans the length ofthe bellows. Covers prevent direct contact with the bellows, offering personnel protection, as well as protection to thebellows from physical damage such as falling objects, weld splatter or arc strikes. Covers also provide a suitable base forexternal insulation to be added over an expansion joint. Some insulating materials, if wet, can leech chlorides or othersubstances which will could damage a bellows.Tie rods eliminate pressure thrust and the need for main anchors required in unrestrained piping system. Axialmovement is prevented with the use of tie rods. Designs that have only two tie rods have the additional ability toaccommodate angular rotation. Limit rods are similar, however they accommodate a specified axial capability.4

Return to Menu-––[APPLICATIONS ENGINEERING]–-–Design ConsiderationsThe addition of expansion joints in a piping system introduces reaction forces produced by the expansion joint thatmust be accommodated in the design of the piping system.SPRING FORCEExpansion joints behave in a manner that is similar to a spring; as movementoccurs, expansion joints produce a resistive force. This resistance is stated as springrate and measured as the force required to deflect the bellows 1” in the axial orlateral direction; or inch-lbs./degree for angular rotation. Spring force is the springrate times the deflection.PRESSURE THRUSTIf we consider a pipe section with blind flanges attached at each end, it isobvious that internal pressure produces a thrust force against the flangesurfaces in opposing directions, however the longitudinal rigidity of the pipeprevents elongation.If we add an expansion joint in the center of the pipe, this rigidity is lost andthe thrust force may overcome the spring resistance of the bellows, producingelongation and possibly uncorrugating the bellows.A pressurized bellows behaves like a hydraulic cylinder. Internal pressure bearsagainst the walls of the convolutions, just as pressure bears against the face ofa piston. This pressure produces a force that is equal to the internal pressuremultiplied by the effective area of the bellows mean diameter ([ID OD]/2)and will cause the flexible bellows to extend outward unless it is restrainedfrom doing so. In most pressure piping applications, pressure thrust is usuallymuch greater than spring force.PIPE ANCHORSBy adding fixed points in the piping system, referred to as main anchors, the expansion joint is prevented fromextending. Pressure thrust force is directed into the immovable main anchor. Now the joint is forced to compress orextend axially solely in response to dimensional changes in the pipe segment located between thesemain anchors.Anchor design requires the consideration of forces due to pressure thrust at system test pressure, which is customarily1 1/2 times the design pressure. In addition, bellows spring forces produced by deflection, friction force due to pipemovement across contact surfaces, forces and moments resulting from wind loading, bending and other influencesmust be considered in the design of anchors.Main anchors are intended to anchor the pipe from motion in any direction.Directional main anchors are, as the name implies, intended to anchorthe piping system in one direction, while allowing movement to occurfrom a transverse direction.5

Return to MenuIntermediate anchors can isolate multiple expansion joints that areinstalled in series to accommodate large motions beyond the capability ofa single joint. This separation is required to insure that each expansion isable to function as intended and not be affected by the flexibilitycharacteristics of adjoining expansion joints. Intermediate anchors reactonly differences in spring force and are not exposed to pressure thrust.PIPE GUIDESWith the addition of an expansion joints and anchors, each pipe segment now behaves like a slender column underthe compressive load of expansion joint pressure thrust and/or spring force bearing against the anchors. Bowing orbuckling at the expansion joint may occur unless the pipe is properly guided.Pipe guides are required to stabilize this slender column, preventing buckling and insuring that pipe growth is directedinto the expansion joint as axial movement.The first pipe guide must be located within four pipe diameters ofeach side of the expansion joint and a second guide placed within10-14 pipe diameters of the first guide. Additional guides may berequired based on guide spacing tables that consider diameter andsystem pressure. A convenient intermediate guide spacing chart isprovided on page 35.The recommendations given for pipe guides represent the minimum requirements for controlling pipelines whichcontain expansion joints and are intended to protect the expansion joint and pipe system from undefined externalforces which could cause system failure.INSTALLATION MISALIGNMENTInstallation misalignment reduces the total movement capacity of the expansion joint. Correction of misalignmentshould be completed prior to installation of the expansion joint. If misalignment can not be avoided, contact one ofour engineers for guidance.CONCURRENT MOVEMENTSExpansion joint movement capacity is listed in this catalog as the non-concurrent capacity for each type ofmovement. Axial, lateral and angular movements usually occur simultaneously, therefore it is essential that theconcurrent movement capacity of the expansion joint be determined. This may be calculated by determining therequired percentage of non-concurrent capacity required to meet each type of specified motion. The sum of thesepercentage values may not exceed 100.Required Axial Movement Required Laterial Movement Catalog Rated AxialCatalog Rated Lateral6Required Angular MovementCatalog Rated Angular 1

-––[JOINT PRODUCT SELECTION GUIDE ]–-–Mid-Corr expansion joints (shown on pages 8-12)employ a standardized bellows design ideally suited forgeneral industrial applications. Offered with flanges orbutt weld ends from 2” to 24” nominal diameter fordesign pressures to 300 psig at 800 F. Large diameteravailable in our Metal Catalog.High-Corr bellows are hydraulically formed to producesuperior fatigue life and maximum strength for severeservice applications. This product provides an excellentmeans of absorbing large pipe motions (up to 7 1/2”).High-corr bellows are available in two styles: FreeFlexing and Controlled-Flexing.Free-Flexing expansion joints (shown on pages13-14) are widely used in process and steam pipingapplications to 50 psig. In addition, the Free-Flexingexpansion joint is recommended for compressorconnections, engine intake and exhaust piping,ventilation and pump suction or discharge lines.Controlled-Flexing expansion joints (shown onpages 15-17) combine the Free-Flexing bellowsdesign with mated neck rings and control ringsbetween each convolution. This ruggedconstruction reinforces the bellows for higherpressure applications. With an external cover thisexpansion joint provides a high degree of safetyfor the most severe operating conditions.Externally Pressurized expansion joints (shown onpage 18) have a heavy duty packless design that enablesthis product to accommodate large amounts of axialmotion at high pressure without the risk of bellowssquirm. Limited to axial movement only, the bellows isfully enclosed within an outer shell which is constructedof standard weight pipe, offering the highest degree ofprotection for the bellows and personnel. Externalinsulation may be added directly over the outer caseand/or direct bured.Expansion Compensators (shown on page 19) providethe inherent performance benefits and safety featuresof the externally pressurized expansion joint design in acompact package. Intended primarily for steam supplyand condensate return lines, as well as hot and chillwater piping, this product is suitable for any smalldiameter axial expansion application.Pressure Relief/Safety Valve Connectors (shown onpages 20-23) combine the design principles of therugged externally pressurized expansion joint with aunique capability to also accommodate lateral andangular movements. Intended to replace devices such asdrip pan elbows, this product enables pressure relief andsafety relief valve discharge pipingto be fully sealed.Flexible Metal Pump Connectors (shown on pages24-25) reduce stresses at piping connections to sensitiverotating equipment such as pumps and compressors.Capable of absorbing thermal growth, pipingmisalignment, vibration and noise, pump connectorsoffer extended service life for all rotating equipment.Non-Metallic Expansion Joints (shown on page 26-27)can also be used for similar applications as the FlexibleMetal Pump Connector in a non-metallic construction.Exhaust Flexible Connectors (shown on pages 28-29)are designed for low pressure applications such asstationary and marine gas turbine and diesel engineexhaust and low pressure ducting. Large motioncapability, low spring forces and reduced weight makethis product ideally suited to thin-wall duct systems.Pipe Alignment Guides (shown on page 32) are anessential component of any properly designed pipingsystem that employs expansion joints. These guidespermit axial motion, while restricting lateral, angularand bowing movements.7

-––[MID-CORR EXPANSION JOINTS]–-–Mid-Corr expansion joints employ a standardized bellows design ideallysuited for general industrial applications. Offered with flanges or buttweld ends from 2” to 24” nominal diameter for design pressures to300 psig at 800 F. Large diameter available in our Metal Catalog.MID-CORR DATASINGLESize RangeAllowable PressureStainless Steel BellowsTemperature LimitsStainless Steel BellowsHow to order:Example P/NDIASTYLE8HMCSENDS PRESSURE CONSFF3006LINER COVERLCAxial TraverseLateral Motion2” to 24”* NPSVacuum to 300 psi-20 F to 800 F. **To 6.28”. . .(depending on size)Up to 2.51”. . .(depending on size)**With special alloys, temperatures of minus 425 F. to plus1600 F. can be handled.STYLEMATERIALS OF CONSTRUCTIONBELLOWS: ASTM A240 T304MCS SINGLEMCT TIEDEND CONNECTIONPIPE: ASTM A53/A10650 lb. Series: Sch. 40150 lb. Series: Sch. 40300 lb. Series: Sch. 40FLANGES: A36/A516-70 Plate (Std) A105 (Opt)50 lb. Series: 150 lb. ANSI B16.5 F.F.S.O.150 lb. Series: 150 lb. ANSI B16.5 F.F.S.O.300 lb. Series: 300 lb. ANSI B16.5 F.F.S.O.COVERS: Carbon SteelTIE RODS: Carbon SteelWW WELD ENDLINERS: 300 Series Stainless SteelFF FLANGED ENDV V VANSTONE END81. Rated cycle life is 2000 cycles per EJMA 7th edition for anyone movement tabulated.2. To combine axial, lateral movements, refer to page 6.3. Maximum axial extension movement is 50% oftabulated axial value.4. To obtain greater movements or cycle life, contact thefactory.5. Catalog pressure ratings are based upon a maximum bellowstemperature of 800 F. Actual operating temperature shouldalways be specified.6. Maximum test pressure: 1 1/2 x maximum working pressure.