... . Our casing are produced by the leading OCTG manufacturers in China like TPCO, Hengyang Valin, Baotou Steel, Jiangsu ... from 4 1/2" to 20". 30” conductor with plain ends or fast connection is also available. Manufacturing ... , BTC) Premium Connections HSM, TP-CQ, RJS (compatible with VAM and HSC) Length range Range 1, 2, 3 ... bevel; 20°bevel Slotted (Screen casing) Casing in accordance with API Spec 5CT