Abstract A valve for shutting off a fluid pressure medium in response to pressure variations in a flow conduit wherein a valve body with a longitudinal bore therein is provided with slide valve means in the bore. There are inlet and outlet port means in the body that communicate with the bore and resilient means tend to urge the valve means in one direction longitudinally in the bore. Passage means in one end of the body receive pressure from the flow conduit, and plunger means is mounted in the passage means and is provided with seal means against which the pressure from the flow conduit acts to tend to move the plunger and valve against the force of the resilient means. A vent to atmosphere from the passage means and one end of the longitudinal bore in the valve body is provided so that if the seal means between the plunger and passage leaks, the pressure from the flow conduit will bypass to atmosphere. Another vent to atmosphere communicates with the other end of the bore. The outlet port means comprises two passages, one of which is adapted to be blocked, depending upon whether the valve is to be used as a high or low pressure controller.
An apparatus for changing the pressure applied to a pressure actuated mechanism responsive to a controlled pressure rising above a maximum value or falling below a minimum value comprising in combination: a. a conduit for applying pressure fluid to said mechanism; b. high and low pressure pilot valves connected in series in said conduit and each being actuatable to interrupt flow of the pressure fluid to said mechanism while at the same time venting said mechanism; c. means for individually actuating said high and low pressure pilot valves to so interrupt said flow and vent said mechanism, the high pressure pilot being so actuated upon said controlled pressure rising above said maximum value and the low pressure pilot being so actuated upon the controlled pressure falling below said minimum value; and d. said low pressure pilot valve having a vent between said controlled pressure and the pressure fluid flow through said low pressure pilot valve to prevent flow of said controlled pressure through said low pressure pilot valve to said mechanism.
Claim 2
Independent Claim
171 words
An apparatus for changing the pressure applied to a pressure actuated mechanism responsive to a controlled pressure rising above a maximum value or falling below a minimum value comprising in combination: a. a conduit for applying pressure fluid to said mechanism; b. high and low pressure pilot valves connected in series in said conduit and each being actuatable to interrupt flow of the pressure fluid to said mechanism while at the same time venting said mechanism; c. means for individually actuating said high and low pressure pilot valves to so interrupt said flow and vent said mechanism, the high pressure pilot being so actuated upon said controlled pressure rising above said maximum value and the low pressure pilot being so actuated upon the controlled pressure falling below said minimum value; and d. said low pressure pilot valve having a vent between said controlled pressure and the pressure fluid flow through said low pressure pilot valve to prevent flow of said controlled pressure through said low pressure pilot valve to said mechanism.
Claim 3
Dependent Claim
51 words
The invention of claim 1 wherein said high and low pressure pilot valves include valve means, plunger means abutting one end of said valve means and responsive to the controlled pressure when the controlled pressure rises above the maximum value or falls below the minimum value for moving said valve means.