... . 2,ISO9001-2008/ISO11960 3,third party inspection supported. 4,API 5CT-1043, API 5L-0699 Linzhou Fengbao Pipe Industry Co.,Ltd. as ... passed. Manufacturing MethodHot rolled seamlessSize (OD)4-1/2”,5”,5-1/2”,6-5/8”,7”,7-5/8”8-5 ... details about us please visit: www.cfbpco.com steel pipe factory Linzhou Fengbao Pipe Co.,Ltd.