1,api 5l/astm a106/a53 gr.b;api 5ct. 2,ISO9001-2008/ISO11960 3,third party inspection supported. 4,API 5CT-1043, API 5L-0699 Linzhou Fengbao Pipe Industry Co.,Ltd. as a seamless pipe manufacturer in the worldwide marketplace specializes in production of casing and tubing, line pipe and various other mechanical and structural steel pipes for different applications.Line pipe Seamless-line pipe/API ...