... - high pressure union: Certification:API 6A Application:oilfield equipment WP:High pressure API 6A Wellhead accessory- high pressure union High-pressure union, ... Ring;oil field equipmentShanghai Jefa Machinery Co.,Ltd specialize in API 6A products as following:1) Wellheads (casing/tubing head, crosses ... valve, etc)3) Fitting(union, manifold,elbows), bop. API 6A Wellhead accessory- high pressure union