Small diameter pipeline, you candigenough space,removal ofdamagedpipereplaced byanewpipelinefor maintenance,themaintenanceoflarge-diameterpipeflange connectioncan be usedtocomplete thefirstremoval ofthe damaged pipe, and thenwelding machineinto theditchmeltingreceivedeach endofthepipelinewithinthe support ring, and thenreplacethepipeflange connection,flange connectionof the lengthmust becalculated in advanceforthe spacingbetweenthepipesize. In addition,youcanusethejacket-typerepairfixturewithacompleteringto repair, but thepatchwithflangeorweldrepairdoes not belong tothepermanentrepair.Therepairofthis typeare generally applicable toburiedapplications,because ofthecompactedsoilwill limitpipelinethermal expansionmovement and theinternal pressurecaused bytensionin generalrepairfolderfrom thelonger thethermoplasticpipesealing the better, it is recommendedtheminimumfixturelength of theouter diameter of1.25-2timesthe nominal pipewhen the pipe istowipeclean, removeallforeign matter, the fixtureshouldbeuniformclamping.Fixtureinstalled,should be completedpriortothewater pressurein thethroughthebackfillcompaction. Destructioninthepiping systemfittingscommonly usedwaytoputa newpipeflange connectionis not recommendedtouse hot air orextrusionweldingto repair. Underwaterpipeline systemin order to completetherepairofunderwater pipelines,theend of the pipemust becarried to thesurface of the waterabove, and thenweldingaflangesupport ring,and thenpipeback intothebottompositionandintheunderwaterscrewtightened. Inaddition,incertainplaces,can be usedtorepairpipeheat shrinkablesleeveorfusedtorepairatubepunctureorleak,many types ofshrink sleeve,thesleevethe insidecoated witha specialsealant,when heatedintothepunctureorjoints, sealantsrelyonmechanical forceto preventa largerspill occurred.