PARTIAL STROKE TEST OF EMERGENCY SHUTDOWN VALVE-METSO NELES

Potential disasters at an industrial processing plant may include an accident
resulting in a massive release of toxic materials, an uncontrollable reactant, a
devastating explosion or any combination of the above. All processing plant must be
guarded from all potential disaster scenarios. Therefore , emergency shutdown valves
has to be sure be operated with fault-free as the valves are kept idle in open position
for long periods and are designed to close and keep tight in case of a hazard occur.
Regular checking has to be perfonned in order to guarantee the function of the valves.
Emergency Shutdown valves have been tested at unit turnaround, using a Full Stroke
Testing and Partial Stroke Testing to demonstrate the perfonnance. The scope of this
project is to verify the technology needed for Full Stroke Testing and Partial Stroke
Testing in order to ensure the perfonnance of the Emergency Shutdown valve. The
testing is simulated by using WideField2 Software (YOKOGAWA) for Full Stroke
Test and FieldCare Software (Metso Neles) for Partial Stroke Test. Partial Stroke
Testing can be a good complement to Full Stroke Testing as it reduces the required
Full Stroke Testing frequency and associated operational impact. Partial Stroke
Testing will detect failure of Emergency Shutdown valves without disturbing the
process flow. Testing is conducted for sixth times. The valve status and its response
to mechanical movement during the test are monitored. Valve perfonnance trend is
analyzed after each partial stroke test to find whether there is any potential of valve
failure. The result of valve test, pneumatics test, breakdown pressure and load factor
are being taken into consideration in analyzing the perfonnance of the emergency
shutdown valve.