SchuF is the inventor of the Piston Bottom Outlet Valve (Patent received in 1926). Piston or Ram valves are most commonly used for dead space free draining.
Ram valves / Piston valves: Ram type drain valve. Piston valve These valves are preferred to Disc type flush bottom valves when full flow is required. Ram.
Valve types and styles Flush bottom valves (referred to as Tank valve, Angle bottom valve, Bottom drain valve, Flush mount valve etc.) are designed to provide drainage and dead space free shutoff for reactors, vessels, autoclaves and storage tanks. Ram (Piston) type valves are suitable for polymer application.
Flush Bottom Tank Valve can have disk, poppet, or ram plunger or rod plunger to fill dead space in tank, aid in mixing and prevent cross batch contamination.