No downtime for valve testing

Safety critical valves require regular testing, but because of their very nature this generally has to be done during shutdown periods.

But now, ICS Triplex has developed a hardware and software package for checking safety and shutdown valves without disrupting production in petrochemical and other safety-critical plants.

The idea behind the valve test package is to partially stroke the valve to check it is not stuck in the open position, and to automate this testing using only the standard ESD (emergency shutdown) components.

The relevant international standard, IEC 61508, now specifies that safety shutdown valves are included in the assessment of the process protection systems. However, operating valves periodically to test them is generally undesirable because of the ensuing loss of production.

The ICS Triplex package checks the movement of the valve after only a few per cent of its travel, before returning to the open position. It satisifes IEC 61508 requirements and confirms the performance of the valve without interrupting the process.

The company says that calculations show a partial closure test every quarter, plus an annual full closure test, will improve the valve's SIL (safety integrity level), as defined by IEC 61508, approximately 30-fold. The package is designed so that tests are done at real valve speed.