Midland ACS

Over Pressurization Device (OPD) Stemsaver

Over Pressurization Device (OPD) Stemsaver

The purpose of the OPD “STEMSAVER” is to protect downstream equipment from over pressure events including regulator failure, thus preventing potential damage and downtime. Applications include the protection of ESD & safety instrumented systems including positioners, actuators and process valve stems. The device includes an integral 3550 series pressure regulator with a protection valve and sensor system built into a common body.

Increases in outlet pressure can occur for many reasons, including failure of key regulator components. Should this occur the device will automatically fail-safe within 30 milli-seconds*. The integral valve will be triggered to shut-off the outlet and either vent the downstream pressure or trap & lock at the secondary preset trip pressure level. The mode of operation can be selected by leaving the exhaust port of the valve open or plugged.

When the integral valve has deployed, the reset button protrudes from the housing providing a positive indication that a fault has occurred; models are also available with air pilot operators or proximity switches to indicate the triggered position. The OPD reduces the potential for damage occurring from increased torque, thrust or pressure values within the downstream system. Once the fault has been corrected the unit can be reset by pushing the reset button on the unit. In line with today’s requirements for space saving, weight reduction and efficiency the system is all close coupled within a compact body.

*Time stated for 4-8 bar variant; please see specification for further information regarding lower pressure versions.