ESD solenoid valve reliability

[amar122amar]

How can we ensure the reliability of ESD solenoid valves? which combination is better (two solenoids in series Vs parallel, 1oo1 Vs 2oo2 logic) if we have redundant solenoid valves to initiate tripping.

 

[JLSeagull]

What is the SIL requirement or reliability objective? Are you trying to avoid a nuisance trip due to a solenoid coil failure; or absolutely trip if required?

For codes and standards, what type application such as hydrocarbon process, toxic, heater fuel system, and what country, etc.?

 

[amar122amar]

1.Are you trying to avoid a nuisance trip due to a solenoid coil failure? YES, RECENTLY A TRIP HAPPENED DUE TO LOOSE SOLENOID COIL.
2. what type application? FLUE GAS VALVE TO POWER RECOVERY TRAIN (EXPANDER).
3. absolutely trip if required? YES
4.country? INDIA.

 

[IRstuff]

Please refrain from using all caps; it's harder to read, and is considered to be shouting.

If your failure was from a loose coil, isn't that a maintenance or component quality problem? It doesn't matter how much redundancy you have if the equipment isn't being maintained or so is shoddy that there's basically no inherent reliability. Your design is only as good as the components that you selected for the fabrication.

What monitoring are you doing to determine whether any valid operation is executing correctly?



TTFN

FAQ731-376

 

[amar122amar]

sorry Mr IRstuff, i used caps just to distinguish between Q and A. Anyways its matter of personal preception if u consider caps as shouting.

what i was asking that if we put 2 solenoid valves in parallel instead of series, what are advantages and disadvantages.

 

[IRstuff]

I would not be so presumptuous to impose only my own personal "preceptions" into a public site.

If you are being troubled by accidental actuations, one
would think that twice as many false actuations from shoddy components would be a serious disadvantage, no?

TTFN

FAQ731-376

 

[itsmoked]

Hi amar122amar.
You can use [ignore]

original text

[/ignore]

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to differentiate between questions and answers or just use different colors [ignore][blue] original text [/blue][/ignore]
[blue] original text [/blue]

In series if either coil opens they both drop out.
If one coil shorts the other may soon short too as it now has twice the voltage across it.

In parallel if one coil opens the other continues.
However if one coil shorts the other will drop out because the circuit protection will trip due to the short.

If you have faulty installations though, as IR is undiplomaticly pointing out, all the safety schemes in the world probably won't help.


Keith Cress
kcress -

http://www.flaminsystems.com

 

[Mandingo88]

All,

I know I am chiming in late, but is it common practice to have IS instruments (solenoid valves) on the same circuit (in series) and are you doing interlock testing on these loop for loop integrity? From a reliability stand point this is a way to check your equipment (maybe annual) and collect data in regards to mean time between failures (MTBF) which can possibly predict when a component of the loop will fail.

 

[itsmoked]

I think some of the confusion is the coils verses the plumbing.

I absolutely agree with your 'plumbing' suggestion. That's the way.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[dpc]

If the solenoid valves are energize-to-trip, then one out of two "OR" logic is typically used.

"Theory is when you know all and nothing works. Practice is when all works and nobody knows why. In this case we have put together theory and practice: nothing works... and nobody knows why! (Albert Einstein)

 

[Mandingo88]

Did I miss something?