... oil drilling equipment- christmas tree consists of the casing head,tubing head and christmas tree.The main technical specifications:1, W ... line of API 6A wellhead equipment including casing heads, casing spools, tubing heads/spools, tubing head adapters, casing hangers, tubing hangers, base ... which engaged in API 6A&16A products for 2 years→Head office in Shanghai ,2 plants in Yancheng, Jiangsu→Over ...