A failure position is meaningful only when the triggering event is specified. A valve can respond differently to lost air, lost power, lost signal or a mechanical fault.
Use a failure matrix
For each credible event, write the required valve response and the device that provides it. For example, a spring-return actuator may address air loss, while positioner configuration defines response to a signal fault. A process hazard review determines the appropriate response; a valve supplier should not guess it from the application name.
Check the path to the final position
Reaching the endpoint requires adequate torque, a clear air path and compatible accessory behavior. A trapped-air device may prevent the motion expected from a spring. A double-acting actuator may drift if the circuit does not provide a defined response. Mechanical jams are not solved simply by naming a failure position.
Specify verification
Request an assembly test that addresses the agreed utility and signal failure scenarios. Record stroke time, endpoint indication and any limitations. If the valve forms part of a safety function, component certificates are only part of the evidence; the complete function requires an application-specific assessment.
Practical checklist
- Failure event, required action and providing component.
- Minimum force or torque throughout the movement.
- Solenoid and positioner behavior.
- Functional test records for the complete assembly.
Discuss your application
Send the process conditions and required valve function for a configuration review. Request a technical quotation ↗