Lockable valve

Claim 1

A rotary plug valve capable of being locked in selected positions by an elongated locking pin having a first enlarged head on a reduced shank and a second separate enlarged cup-shaped head arranged to receive and be locked to the shank and released from the shank by a key axially inserted into the shank, said rotary valve comprising: a body having a seat and provided with a flow passageway therethrough intercepted by said seat; a valve member having a flow passage therethrough and being rotatable in said seat between a selected open position in which its flow passage registers with the flow passageway in said body and a selected closed position in which its flow passage does not register with the flow passageway in said body; said body being formed with means defining a transverse bore therethrough of a diameter to receive the heads of the locking pin; said valve member being provided with means defining a transverse bore arranged to be aligned with said bore in said body when said valve member is in a selected position for locking said valve member against movement relative to said valve body, said transverse bore in said valve member having a central portion of a diameter less than the diameter of the heads of the locking pin but sufficient to receive the shank thereof, and being enlarged at its ends to a diameter substantially equal to the diameter of said bore in said valve body so that a portion of each of the heads of the locking pin extends into a respective enlarged portion of said transverse bore in said valve member; said bores being constructed and arranged so that the heads of the locking pin do not extend beyond the exterior of said valve body when the valve is locked.