.Introducing of international advanced technology, high pressure union is forged by high tensile alloy steel. Strict heat treatment ensures joint¡¯s uniform metallographic microstructure as well as pressure bearing ability. All materials conform to ASTM and AISI. Technical data are subject to API Spec 6A standard. The union obtains abilities of reliable sealing, convenient handling and good changeability. Joint threads can match pipeline or tubing. Butt welding or non-pressure sealing end joint is adopted.