Partial stroke testing system goes remote

London – Dutch valve safety product maker Netherlocks has developed the facility for entirely remote operation of its Faith partial stroke test (PST) system for ESD and HIPPS* valves.

Online testing of these critical valves can now be initiated and performed from the safety and convenience of the control room, without having to manually access the valve, the company said.

Conventionally, operators have to access the valve itself to manually insert a key to start a test. The new development means that the entire process can be done remotely from the control room, making it significantly easier and faster, Netherlocks claims.

The Faith system is designed to facilitate partial stroke testing of valves, without any risk of overshoot or process interruption. The test is never aborted without getting results, and the unique design means that tests can be performed at real speed - just as it would be for real operation in an emergency.

A mechanical limit on the degree of valve closure is said to guarantee there is no danger of actual shutdown or upsetting the plant due to overshooting of the test angle.

Netherlocks describes its Faith system as a universal add-on product which is fitted directly between the valve and the actuator and replaces the original couplings.

During partial stroke testing, mechanical steel blocking pins ensure that the valve can only turn to the preset test angle of 20 degrees. This, notes the manufacturer, also allows for maintenance during production.