Lockable latch

Device for locking a turning handle of a valve, preferably of a rotary valve, especially preferably of a ball valve or a shut-off valve, containing a handle for actuating a shut-off element of a valve, a latching ring that can be arranged in a rotationally conjoint manner on a valve housing support for an actuating device and an adapter that can be arranged on a drive journal of a shut-off element such that it can be fixed and released again, wherein the adapter and the handle are connected to one another in a releasable manner, wherein an axially displaceable and non-rotatable sliding ring is arranged on the handle, wherein the sliding ring can be displaced axially into a locking or open position and in the locking position the sliding ring locks the rotational movement of the handle and the handle cannot be removed from the valve on account of the position of the sliding ring in the locking position.