High Flow Reversing Relay (M2500A)

The Model 2500A Bias Reversing Relay provides an outlet pressure that decreases in direct proportion to increases in input signal. The input signal that acts on the Diaphragm Assembly opposes the Range Spring force and closes the Supply Valve to decrease output pressure, according to the formula (Po = K - Ps); where Po is output pressure, K is the spring constant, set by the screw, and Ps is signal pressure. The M2500A pneumatic relay delivers this performance at a flow capacity of 150 SCFM (255 m3/HR), to provide fast response and tight control over your application.


  • Control sensitivity of 1" water column
  • Flow capacity of 150 SCFM (255 m3/HR)
  • Soft Supply and Exhaust Valve seats
  • Balanced Supply Valve
  • Aspirator Tube design
  • Separate Control Chamber


  • Allows use in precision applications
  • Provide fast and responsive system operation
  • Minimises air consumption
  • Minimises the effect of supply pressure variation
  • Compensates downstream pressure droop under flow conditions
  • Isolates the diaphragm from the main flow to eliminate hunting and buzzing

See PUB103-005 for further information.

High Flow Reversing Relay (M2500A)