The support has a connection housing (8) adjoining a valve lock (5), and a boom (9) carried by the connection housing and resting against a valve housing (1) in a pivoted-out end position. The boom is connected to the connection housing in terms of pivotal movement under clamping. A blocking device allows the pivotal movement of the boom in one direction. The blocking device has spring-loaded grid plates with teeth and is formed by a pawl arrangement. The blocking device is arranged in the connection housing.
