Safety valve arrangement

摘要

A safety valve arrangement for an installation operating with a pressure medium has a pressure medium input and a pressure medium output connected by a valve. The valve comprises a valve seat and a valve closing element. The valve closing element is moveable between an open position and a closed position and has an active surface that is subjected to the pressure medium in the opening direction of the valve. The valve closing element also has an auxiliary surface that is subjected to the pressure medium in the opening direction of the valve only when the valve closing element is lifted from the valve seat. A spring arrangement holds the valve closing element closed and the valve closing element moves from a closed position to an open position when the pressure medium acting upon the valve closing element is greater than the opposing force of the spring arrangement acting upon the valve closing element. The safety valve also has an auxiliary valve which also connects the pressure medium input to said pressure medium output. The auxiliary valve is moveable from an open position to a closed position. The spring arrangement also holds the valve closing element of the auxiliary valve closed. The valve closing element of the auxiliary valve is opened when the force of the pressure medium acting upon the valve closing element is greater than the opposing force of the spring arrangement acting upon the auxiliary valve closing element. The safety valve arrangement may also have a choke located between the valve and the pressure medium output which throttles the flow of the pressure medium.