Patented Mechanical-Seal Design

Hemiwedge Valve Corporation”sHemiwedge Cartridge Valve features a patented mechanical-seal designfor critical service applications. The valve utilizes aspects ofball valves, gate valves, and even triple-offset butterfly valves toprotect the sealing surface during valve operation. A taperedhemispherical closure member (the hemi) rotates around a fixed core andwedges into a fixed seat to affect a mechanical seal. The closuremember is rotated a quarter-turn by a valve stem, which may be operatedmanually with a wrench or gear operator or automatically with apneumatic, hydraulic, or electric actuator. Unlike designs with arotating ball or plug, the valve features a constant fixed core withinthe body to provide protection of the seating surfaces when the valveis opened, as well as minimizing turbulence as the valve is eitheropened or closed. This constant fixed core directs the fluidthrough the valve and not at the seats during the opening and closingof the valve. The line features an all-metal seat design thatprovides valve closure tightness to ISO 5208:2008 Rate B. Hemiwedgecartridge valves are designed in accordance with ANSI B16.34 and arealso available with API 6D certification. They are available in sizesfrom two inches to 10 inches and in ANSI Classes 150 to 900 Class andother sizes are currently in development. The valve is available incarbon steel, low alloy steels, stainless steels, and other materialssuch as duplex stainless steel, superduplex stainless steel, Inconel,Hastelloy, and Monel.