摘要 |
A valve of the type which is actuated under the pressure of the medium it controls and in which axially-aligned actuating and damping pistons are disposed within cylindrical relief and damping chambers and are connected to a valve element engageable with a valve seat disposed between inlet and outlet valve ports. The actuating piston acts under the pressure of the medium it controls to actuate the valve element in response to a reduction in pressure in the relief chamber. The invention itself resides in the provision of a restricted passageway which interconnects the relief and damping chambers whereby the pressure in the damping chamber will be reduced slowly in response to a reduction in pressure in the relief chamber whereby, if the valve should stick or otherwise become slow-acting, the pressure within the damping chamber will assist and insure that the valve is actuated even though it may not be in the best operating condition.
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