The 4, 6 and 8" wafer checks offer built-in resilient seating performance for the installer. Each valve is manufactured with integral O-ring seals as part of its end condition. Flange gaskets are not required. If being installed with a groove flange adapter, a simple washer can be inserted to provide easy seating and installation. Spring-loaded, the Kennedy wafer check can be installed easily in either the horizontal or vertical. This valve is an absolute must for limited-space installs.