A Deadman valve forces someone to manually open the valve, and will automatically shut itself off when the handle is let go by a spring action. Without the pressure against the spring, the handle will return to its original closed position. A deadman valve could also be referred to as a "spring return handle".
Unique Control Systems Spring Return (Deadman) Handles are manufactured from heavy duty stainless steel components to withstand frequent daily use in refueling, sampling, drains, and other OSHA applications that require positive closure of a manual valve. Each Handle has a locking device as standard to lock the valve in the preferred position. The Handle is available in three sizes that mount directly to the rugged investment cast ISO 5211 mounting.