Locking device for lid of expansion container of cooling system, preventing opening when excess pressure is created in container

摘要

A vertically movable bolt (15) with a piston element (19) attached to one end and enveloped by a helical spring (27) is accommodated in a cylindrical housing (17) located at the lower side of the lid (1). When the cooling fluid exceeds a certain temperature, the pressure inside the container increases, acting on the piston (19) which is moved against the forces of the spring (27) into the container with its lower end, preventing the lid (1) from being opened.