Necessity of Handwheel for ESDV

[e43u8]

Dear All,

Is there an standard/practice mentions that the ESDVs should be equipped with no handwheel due to safety matters?

 

[gerhardl]

No.

An ESDV is the general abbreviation for an Emergency Shutdown Valve.

ESDV as a function for a valve excists therefore in shutdown systems for for the complete range of excisting fluids, and all possible emergency shutdown situations. 'ESDV' might even be used as for hand operated valves.

Emergency shutdown operations will however often require no possibillities for operation except controlled or automatic operationin an actual emergency situation. Hence no handwheel mounted for for possible wrong operation. This will often be included as a requirement in the actual operation standard for the emergency shutdown system.

 

[e43u8]

Thanks gerhardl

Please let's know if there is any standard/practice mentions no handwheel needed to be mounted in ESDV?

 

[LittleInch]

e43u8,

You appear to be quite an experienced engineer so I won't go back to basics, but I don't believe there is a "standard" or code which mandates no handwheels on ESD valve actuators.

There may be individual company specifications / requirements which say this, but in reality not many valves will be able to be manually opened or closed against what is commonly a spring actuator. However there may be times when one is needed and then it becomes a matter of how the valve is opened and what permissions etc you need. It's also pretty rare to see an ESD valve with a handwheel, but not unknown. You also do get manually set valves where you open against a spring, latch it via held closed latch and in those locations you may need a handwheel.

E.g.

https://www.maxairtech.com/fail-close-valve-w-manual-override/

This is a fail closed pneumatic valve.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[1503-44]

Depends on the service. Sometimes it can be convenient to be able to open a valve (for black start, etc.) after the nitrogen supply bottles are empty, or the emergency generator has shut down. I had to do it a couple of times using the jack lift I borrowed from my rental car. I have also had to keep a control valve positioned in the same manner. I'll be in trouble if car rental companies ever stop providing those things.

“What I told you was true ... from a certain point of view.” - Obi-Wan Kenobi, "Return of the Jedi"

 

[gerhardl]

Hello e43u8,
it seems that you possibly could have a problem finding an argumentation in a situation where you want to avoid ESDV combined/equipped with handwheel?

In case, we could probably help you better if you gave us more information.

 

[e43u8]

Hello gerhardl,

It's the subject of our challenge with client; they want the ESDVs equipped with handwheel for maintenance cases but we say an emergency valve shouldn't be equipped with handwheel to avoid the risk potential due to inadvertent opening/closing by operator.

 

[gerhardl]

e43u8,

Thougt it might be something like that! Generally I agree with you.

The argumentation will depend on the situation. What is the worst that could happen with or without possibillity for extra manual operation?

Normally regular inspection, maintenance and tests should keep an automatic ESDV in a system dependable. In very critical cases a redundance system with double or trippelvalves in parallell might be a solution.

It is also possible to have a handwheel 'locked down' only to be used as an extra if anything else fail, or as an extra locked down bypass.

My suggestion is that you sit down with the customer and analyse the different situations to find the best solution.

That is what both parties want.

Good luck!

 

[1503-44]

Nobody is going to try to close them when there is power gas or electricity keeping them open, unless there really is some kind of emergency, yet when there is no power, you often need to open them. I think you've got a weak argument. In any case all you have to do to close them is push a button. Inadvertant risk is not mitigated.

The client is (almost) always right.

“What I told you was true ... from a certain point of view.” - Obi-Wan Kenobi, "Return of the Jedi"