API 5L GrB heat insulation steel pipe OD:10.3mm-1420mm WT:Sch SGP-XXS ... :6m,random length Application:boiler pipe API 5L GrB heat insulation steel pipeOD:10.3mm-1420mmWT:Sch SGP-XXSLength:6m,10m ... ,X56,X60,X70,TP304L,TP316L, P91 API 5L GrB heat insulation steel pipe,API,PED,ISO certificate,DIN,JIS,BS standard