The common materials:20# and Q345 .Technical standard:API 5L B,ASTM A106 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, structural pipe GB/T8162-1999 and hydraulic support pipe GB/T17396-1998