EXPANSION JOINT DESIGN GUIDE - Metraflex …

1 METRALOOP EXPANSION JOINT DESIGN GUIDES pecial production Metraloops are certified by theAMERICAN GAS ASSOCIATIONfor use on gas pipe factory for moreinformation. Catalog LOOP93 Certified by theAMERICAN GAS ASSOCIATIONfor use on gas pipe lines. NO THRUST LOADS MINIMAL ANCHOR LOADS MINIMAL GUIDING SEISMIC RATINGS2323 W. HUBBARD ST CHICAGO, IL 60612 800-621-4347 312-738-3800 FAX 312-738-0415 METRALOOP ADVANTAGE .. DESIGN FREEDOM!XXX6' - 6"13'36"46"AnchorLoads12800 GuideBellows EXPANSION JointHard Pipe LoopDesign ConditionsPipe -6 inch Schedule 40 Movement -4" Axial CompressionPressure -150 PSIT emperature -300 FLength of Run -177 feet 98% less anchor load thanBellows EXPANSION JOINT 83% less anchor load thanHard Pipe Loop 75% less space required thanHard Pipe LoopDrawn to ScaleXXXA nchorLoads12800 EFITS.

2 Movement in all directions - absorbing seismic energy withlow activation forces, standard seismic bracing is adequatefor adjacent piping. Ball or bellows joints havesignificant breakaway torques or thrust loads that exceedstandard seismic bracing. Fire Sprinkler Systems - UL listed, the Fireloop providesseismic protection in a compact, easy to install compo-nent. See the Fireloop DESIGN GUIDE or for full details. Gas - Protect against devastating fire by certified Metraloops in gas lines asthey cross the building's seismic joints or at theconnection to gas-fired equipment.

3 Reduce Costs - Metraloops are far less expensive thanalternative seismic EXPANSION joints, particularlyball-joints. Protect Equipment - Metraloops allow equipmentsuch as boilers and chillers to move independentlyfrom the building during an earthquake. Preventnozzles from cracking or shearing in earthquakesby installing Metraloops at the Seismic Installations,see Page by theAMERICAN GAS ASSOCIATIONfor use on gas pipe lines. YOU R FI RST CHOICEBECAUSE .. Path of Least Resistance - which is why GUIDESare not always required.

4 With an incredibly low force tocompress, the Loop is the path of least resistanceabsorbing thermal movement before the pipe begins tobow. Long before thermal EXPANSION develops enoughforce to start to compress traditional bellows type jointsor hard pipe loops, the column loading strength of pipeis exceeded and the pipe begins to bow. Hence theneed for numerous and specifically placed pipe guidesup and down the pipe run in traditional piping systems. Anchor Loads - Almost None - compared to bellows orhard pipe loops. Bellows type joints exert tremendousanchor loads, requiring answers to: is the concretethick enough, what size anchor bolts, is the steel strongenough, where do I make the attachments?

5 ?? TheMetraLoop anchor loads are so low; these questionsmay be immaterial. Amount of movement - virtually any. Stock sizes areshown on pages 4-5, however movements greaterthan 3 or 6 FEET! are not L L M E TA L L I C C O N S T R U C T I O NTYPICAL SPECI FICATIONP rovide flexible EXPANSION loops of size and type notedon drawings. Flexible loops shall consist of two flexiblesections of hose and braid, two 90 elbows, and an180 return assembled in such a way that the pipingdoes not change direction, but maintains its coursealong a single axis.

6 Flexible loops shall have a factorysupplied, center support nut located at the bottom of the180 return, and a drain/air release plug. Flexibleloops shall impart no thrust loads to system supportanchors or building structure. Loops shall be installedin a neutral, pre-compressed or pre-extended conditionas required for the application. For steam service,loops must be installed with flexible legs horizontal toprevent condensate buildup. Install and GUIDE permanufacturer s recommendations. Materials ofconstruction and end fitting type shall be consistent withpipe material and equipment/pipe connection natural gas service, connectors shall be Flexible EXPANSION loops to be Metraloop asmanufactured by the Metraflex Company , Chicago, OF CONTENTSM etraLoop Drawing.

7 Inside Front CoverSeismic Benefits ..Inside Front CoverTypical Specification ..1 How the MetraLoop Works ..2 Typical Installations ..3 MetraLoop Selection Chart - Sweat, Thread & Flanged Ends ..4 MetraLoop Selection Chart - Weld & Grooved Ends ..5 Installation/Guiding Considerations ..6 Applications ..7-9 Thermal EXPANSION Applications ..10 Seismic Applications ..11 Test Report ..12 Pressure Drop Charts ..13 MetraLoop Drawings ..14-16 Terms and Conditions ..17 CARBON STEEL,COPPER ORSTAINLESS ENDSBRAZEORWELDMENTSTAINLESS STEEL ORBRONZE FLEXIBLEMETALLIC HOSESTRESS RELIEVINGWELD COLLARSTAINLESS STEELOR BRONZE BRAIDTHERMAL EXPANSION :The MetraLoop is simply a flexible variationof the tradition hard pipe loop.

8 For any givenlength of pipe and given temperature change,the amount of movement can be calculatedand the appropriate MetraLoop can bedesigned. When installed in a pipe run theMetraLoop s legs simply bend laterally tocompensate for the pipe s EXPANSION orcontraction. Unique to the loop is theincredibly low amount of force required tobend its legs, minimizing anchor loads,guiding and installation MOVEMENT:The two flexible legs connected by anunrestrained return bend, will allow apredetermined amount of pipe movement inany direction.

9 (Typical DESIGN movement is 4 inches in any direction, howevermovement of several feet in any direction ispossible). With the loops extreme flexibilityand low force to move, the loop absorbs theseismic energy and imposes minimal loadson the adjacent pipe hangers, supports ornozzle loads on major equipment. See page11 for more OW T H E M E T R A L O O P WO R K SSEISMIC MOVEMENT: ALL DIRECTIONALTHERMAL EXPANSION : AXIAL MOVEMENT3 Illustrated below are the typical orientations for the MetraLoop. No support is required for the 180 return bend for standard loops 2-1/2 diameter and smaller.

10 However due to the weight of the return bend and the extreme flexibility of the loop, larger sizes require support toprevent the 180 from sagging in all orientations except when installed hanging down as shown in illustration #2. Guides are recommendedbut not always required see bottom of page 6 for more Note- For steam service minimizing the entrapment of condensateis crucial and loops should be installed as shown in illustration #1. Detailed installation considerations are noted on the following Y P I CA L I N S TA L L AT I O N SSUPPORT MUST BE PROVIDED TO PREVENT THE LOOP FROMDROOPING OR TORQUING PIPE.