Partial stroke test device avoids costly downtime
Dutch process-interlocking and valve-control specialist Netherlocks has developed a method of testing emergency shutdown (ESD) and high-integrity pressure-protection system (HIPPS) valves during normal operation of a plant, avoiding the loss in productivity caused by conventional testing methods.
Dutch process-interlocking and valve-control specialist Netherlocks has developed a method of testing emergency shutdown (ESD) and high-integrity pressure-protection system (HIPPS) valves during normal operation of a plant, avoiding the loss in productivity caused by conventional testing methods.
The Fail Action Integrity Test Handling (FAITH) system limits the stroke of the valve-actuator combination to just 20°, enough to guarantee the reliability of the valve without impacting on production.
Valves used in ESD and HIPPS fail-safe procedures that have not been operated for a long period of time risk becoming immovable due to the actuator and valve seals becoming stuck together. Should an emergency shutdown become necessary and one of the valves will not close, an extremely dangerous situation could arise.
The conventional manner of testing these valves involves closing them completely, which leads to costly downtime, and can only be carried out during a complete plant shutdown. Since complete shutdowns are very rare events, plants tend to install an expensive, over-sized actuator to 'crack' the sticking valve. The system devised by Netherlocks removes the need for such an actuator, while enabling tests to be performed more frequently and conveniently.
It also replaces the standard bracket and coupling between the actuator and valve, and will allow the valve to be partially operated only when the correct linear key has been inserted.