Control System - Shutdown Valve

Because you don't want remote operation to control the valve. This is why they still make manual valves. Does it make sense to remotely control a faucet to wash your hands or a toilet valve so you can flush?

Thanks for response,

please tell me why a shutdown valve should be control by ESD system,not PCS or Fieldbus system.

what is different between ESD and PCS?

Thanks again.

Think about it:

• what job does each one do?
• what happens on power failure?
• what happens on instrument air failure?
• what happens during a fire?

Has this installation been through a formal HazOp Study yet?

What is the full-forms of the abbreivations ESD and PCS?

The name shutdown valve you are mentioning here is Emergency shutdown valve. It depends on you Cause & Effect matrix. This valve normally controlled by ESD(Emergency Shutdown System), normally a seperate PLC in which seperate program will be devloped with reference to the cause & effect martix, which is quite different from PCS and normally this valve will not be controlled by PCS.

If you are correct that ESD is Emergency Shut Down and not Electro Static Discharge, Equipment Status Display, Elliot Simon Data center, or several hundred other acronyms then the answer is obvious. An Emergency Shut Down system must be an extremely reliable separate system than the operations control system. Often the root cause of a machine requiring an Emergency Shut Down is the control system has failed in some unknown fashion. So another working system then must be used to stop the machine.

If ESD does not stand for Emergency Shut Down then the OP is SOL. Maybe even FUBAR. One can hope for just a SNAFU. But I ask you, DILLIGAF? Not by one RCH. GAL

For Information FieldBus does not generate Digital Outputs neither it takes Digital Input its purely meant for Control Loops,

When You look at IEC 61508 You will observe that Equipment under control -EUC shall be controlled by seperate dedicated Reliable , controller.It shall be implemented only for SIF And shall not mix with BPCS(Basic process control system )

Regards

Jose

I see OP used alot here. What does that mean?

The two most common uses of it are "output" and "original poster". Most bets are on the latter though it could be quite confusing....

Many gas and oil boilers' shutdown valves are controlled by string theory ():

• A piece of sisal string is arranged so as to hold the main gas supply valve, which is weighted to close under the effects of gravity, in the open position. In the event of a burner malfunction and a local fire outside the burner assembly, the string burns through, releasing the closing mechanism on the gas supply valve, and the supply is turned off, shutting down the boiler. Fieldbus? Pah!