1.We produce pipes ourselves 2.OD:219-2420mm,WT:5-30mm,length of pipe:3-18m 3.certificate: API 5L & ISO Carbon Steel Pipe Fitting Professionally Manufacture Of China:Tianjin Rongkun PIpe Fittings Co., Ltd (TJRK) is a professionally managed company, holding ISO 9001:2008 certification for International Standard. TJRK quickly moved to establish itself as a a leading company in china as manufacture, ...