OPRS Valves


Accurate, Safe Pressure Relief
The OPRS buckling pin pilot-operated valve reliably relieves the pressure of large volumes of gas in process systems, should an over-pressure situation occur. With this buckling pin design, the system's pressure holds the valve closed during normal operation, thus maintaining leak tightness in accordance with API 527. When the process system exceeds the set pressure, the valve activates at a controlled speed and pressure is relieved, achieving better fluid control.
In many applications across the globe, buckling pin relief valves are an integral part in the protection of pressure containing equipment. Such valves are located within bypass lines around automated control valves or on/off valves, in accordance with API 537 and a variety of other pressure containing equipment.

A Pilot (smaller) buckling pin valve achieves a precise pressure setting time after time
In comparison to other buckling pin valves, the OPRS-100 Model utilizes a much smaller pilot valve to precisely control the operation of the main valve. Smaller buckling pins have a more favorable slenderness ratio tied to improved precision in repetitive, consistent pressure settings.

Maintenance is a one person job
Local and remote activation sensors and limit switches advise the status of the buckling pin valve in normal operation (closed) and during an overpressure event (open). Resetting the valve takes less than 10 minutes.

An easily accessible design coupled with proven technology allows for re-seating the valve and replacing the spent buckling pin external to the process stream and with minimal downtime. It is not necessary to open the adjacent companion flanges to reset the valve thus reducing potential operator exposure to the process.


buckling pin pilot-operated valvebuckling pin pilot-operated valve

Design features

  • Proven buckling pin technology
  • Upstream pressure holds piston tightly on seat
  • Small buckling pin controls set point
  • Regulated opening rate
  • Positive shut off until pin buckles
  • Quick reseating, buckling pin may be changed in minutes
  • Minimal fugitive emissions
  • In overpressure event, there are no pieces to separate
  • No fragments flow to the downstream piping


  • Constructed to ASME section VIII
  • Standard body materials include ASME SA234, SA105, and SA516-70 internals are ASME SA279-304 and 316 and SB149. Standard flange rating is ANSI 150# RF.
  • Requirements for capacity are calculated using API 520 formulas.
  • Quality documentation is available for all aspects of fabrication and testing

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