Detailed Product Description Welded steel pipe common materials:20#and Q235.Technical Standard:API 5LB,ASTM ... A53 GR.B;High-pressure boiler pipe GB5310-1995,Special pipe for fertilizer making GB6479-2000,pipe for petroleum cracking GB9948-2000,low ... -and-medium-pressurre boiler pipe GB3087-1999,Fluid pipe GB/t8163-1999,structural pipe GBT8162-1999 and hydraulic support pipe GB/T17396-1998