What Are Hammer Union Seals? Hammer unions are critical pipe connectors used in oilfield systems for transferring high-pressure fluids such as drilling mud, crude oil, and fracturing fluids. Each hammer union connection relies on a precision-engineered seal ring to ensure a leak-free joint under extreme pressure and temperature conditions. At XHH Seals, we manufacture high-performance hammer union seal rings designed to provide reliable sealing in harsh environments—up to 15,000 psi. XHH...