Frequently Asked Question
In order to meet Target SIL 3, we have to apply PVST (Automatic; Interval 3 Months; Coverage 80%) for both valve groups. This means if I input ESD as an interface module for Valve 2, it looks like ESD is also diagnosed by PVST; (Actually, ESD is not relat
Last Updated 5 years ago
You can select PVST for the final element group and if you are using the SERH for the solenoid, actuator and valve, the tool will select the failure rates associated with PVST. Since the ESD is input as a 'my own' device it only has the failure rates you enter to work with. These will not be modified by selecting PVST. So in this case, I would enter the failure rates you have listed for no PVST for the ESD and this should accurately represent the situation.