Mechanical Pressure Switch

摘要

Embodiments of the invention provide a normally open valve, a normally closed valve, and a combination valve. The valves include a valve body with an inlet coupled to a fluid supply line, an outlet providing a service flow of fluid, a vent venting to atmosphere, a lower piston, a lower diaphragm, and a mechanical valve actuator. The mechanical valve actuator includes an upper piston, an upper diaphragm, a pilot piston with a bore and a plunger, and a spring. The spring is positioned either inside the pilot piston for the normally open valve or inside the upper piston for the normally closed valve. The valves are actuated based on a control fluid entering a system pressure port and exceeding a pressure set point in order to either open or close the valve.

主权项

1. A valve that is normally open, the valve adapted to be coupled to a fluid supply line, the valve providing a service flow of fluid, the valve receiving a control fluid, the valve in fluid communication with atmosphere, the valve comprising:
a valve body including an inlet coupled to the fluid supply line and an outlet providing the service flow of fluid; a restriction wall positioned between the inlet and the outlet, the restriction wall defining a passageway for the service flow of fluid; a sealing mechanism configured to selectively block the passageway for the service flow of fluid; a mechanical valve actuator configured to translate within the valve body separately from the sealing mechanism; a spring positioned inside the mechanical valve actuator and configured to engage the mechanical valve actuator in order to open the valve; and a bonnet coupled to the valve body, the bonnet including a system pressure port adapted to be coupled to a control line, wherein a pressure in the control line exceeding a pressure set point and causing the mechanical valve actuator to move downwardly, thereby compressing the spring, and causing the sealing mechanism to engage the restriction wall so that the sealing mechanism blocks the passageway for the service flow of fluid in order to close the valve.