currently we carry out ESD function test on yearly basis and I am suggesting to review the test frequency
I would like to have some details based on your area work and sharing your view:
· How many TSO (Tight Shut Off) valves require proving test at area installation?
· What method of TSO do you use and how credible?
· Do you use replacement basis or remove for service while the process is left down?
· Do you prove leak test for all ESDV and EDPV
· What is the frequency of TSO leak proving?
Do you have electronics procedure in which you can extend a copy to me
ESD Valve 
