Pressure Sensing Valves

Pressure Sensing Valves have a wide range of functions and uses and as the title suggests, operate on a principle of balancing the inlet pressure against a spring until the setpoint has passed and then the valves change state.

Lock-Up Valves are used in valve automation circuits to isolate the actuator when the supply pressure starts to fall so that the operation of the valve is not affected by falling pressure. Single or dual circuit versions are available for single acting or double acting actuators and the valves are designed to be very sensitive to tiny changes of the inlet pressure so that they switch instantly.

Pneumatic Pressure Switches are sometimes known as Switching Valves or Relays and work in a similar manner to Lock-Up Valves. Pneumatic pressure switches are available with 2 way (2/2) or 3 way (3/2) output valves and are often used in valve instrumentation circuits to automate the changing from a compressed air supply to bottled nitrogen if the air supply falls below the setpoint.

Overpressure Valves, Overload Protectors or Limiters are designed to protect the downstream instruments connected to them by isolating them from the inlet pressure once it reaches the valve setpoint. These valves are rated to survive very high pressures that would destroy gauges, switches or transmitters that may be fitted to them.