API seamless carbon steel pipe carbon seamless steel pipe. API 5L .ISO9001 OD:1/2''-32'' WT:2.11mm-59.54mm ASTM A 106 GR.B high quality and low price the common materials;BS1387, technical standard:API 5L B,ASTM A 106 GR.B,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-pressure boiler pipe GB3087 -1999,fluid pipe GB/T8163-1999,structural pipe GB/T8162-1999 and hydraulic support pipe GB/T17396-1998.