1 reply to this topic

[hal1981]

Hi guys,
As you know, on/off valves consume air in start-up / shutdown condition. My supervisor believes because these valves will not work simultaneously, considering 10% of them in air consumption calculation are enough.
But I think because they are "fail to close" and have "three way solenoid valve" after total SD, all of them consume instrument air simultaneously. So I consider 100% of them in instrument air consumption calculation.
What do you think?

Thanks much!

[hianbotech]

Hi Hal1981

You should talk with instrumentation group in order to undestand when these types of valves will consume air. There are not an unique answer. Each plant has different types of on/off valves

 

Normally during shutdown conditions the valves will go to a safe position with no air requirements.

 

Regards