INTERNATIONAL PATENT: CHINA NATIONAL PETROLEUM CORPORATION, 中国石油天然气集团有限公司, CNPC BOHAI PETROLEUM EQUIPMENT MANUFACTURING CO., LTD, 中国石油集团渤海石油装备制造有限公司, NORTH CHINA PETROLEUM STEEL PIPE CO. LTD., 华油钢管有限公司 FILES APPLICATION FOR "SPIRAL SUBMERGED ARC WELDED PIPE FOR HYDROGEN TRANSPORT PIPELINE AND PREPARATION METHOD THEREFOR"

GENEVA, May 26 -- CHINA NATIONAL PETROLEUM CORPORATION (9 Dongzhimen North Street,Dongcheng District, Beijing 100007), 中国石油天然气集团有限公司 (中国北京市东城区东直门北大街9号), CNPC BOHAI PETROLEUM EQUIPMENT MANUFACTURING CO., LTD (CNPC Tianjin Building, No. 83, Second Street, Tianjin Economic and Technological Development Zone,Binhai New Area, Tianjin 300457), 中国石油集团渤海石油装备制造有限公司 (中国天津市滨海新...