difference between XV and SDV valves

[ipwnftw23]

Hello,
I would like to know the difference between XV and SDV valves

i apericiate any help

 

[LittleInch]

Typically XV is a simple on off actuated valve which fails in position on loss of power or signal.

SDV is a shutdown valve which typically fails closed on loss of signal our power by using stored energy, normally a BIG spring.

The difference should be shown in your standard p & id drawings

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[ipwnftw23]

Thanks for your answer

 

[Krimskiy]

a shutdown valve is sometimes referred as XXV