... ASTM A213 T91 alloy tubeWe are Tianjin BoReiXiang Steel Pipe Sales Co., Ltd.-----American Petroleum Institute:Certificate of Authority to use the Official ... cooperation with Chengdu Steel Group Co., Ltd., Baotou Steel Group Co., Ltd., Baoshan SteelCorporation and Tianjin Steel Pipe Group Co., Ltd.in China.With many years ...