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About PSA Pnuematic Program Valve Maintenanc

08/14/2011 8:31 AM

want to know all about causes of psa pneumatic valve failure to open...

thanks!

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Guru
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#1

Re: About PSA Pnuematic Program Valve Maintenanc

08/14/2011 10:14 AM

May I know what is psa? And why it should open?

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#3
In reply to #1

Re: About PSA Pnuematic Program Valve Maintenanc

08/15/2011 6:12 PM

PSA STANDS FOR PRESSURE SWING ADSORBERS,

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Guru
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#2

Re: About PSA Pnuematic Program Valve Maintenanc

08/15/2011 4:29 AM
  • Air supply failure or low pressure?
  • Air signal failure or low pressure?
  • Something jammed in the valve?
  • Damaged or broken components in the valve?
  • Manual override fastened in the close position?
  • Etc.
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#4
In reply to #2

Re: About PSA Pnuematic Program Valve Maintenanc

08/15/2011 6:15 PM

MAN I CHECK THE AIR SUPPLY ITS OK

ALSO NOTHING JAMMED

NO BROKEN COMPONENTS IN VALVE

SOMETIMES IT OPEN AROUND 2 TO 3 CYCLE IT WONT OPEN..BUT THE SIGNAL IN DCS MONITOR IS OPEN..

MANUAL OVERDRIVE YOU MEAN THE SOLENOID VALVE?

THANKS MAN..IF YOU HAVE MORE PLEASE HELP ^_^ THX AGAIN

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Guru
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#5
In reply to #4

Re: About PSA Pneumatic Program Valve Maintenance

08/16/2011 3:05 AM

Thanks for clarifying PSA. First of all I want to request you use small case instead of total capitals, like other members are using.

"MANUAL OVERDRIVE YOU MEAN THE SOLENOID VALVE?"

No, it's not a solenoid valve, also it's not "MANUAL OVERDRIVE" but "manual override" PWSlack (GA to him) simply mean whether valve was tightly closed by hand using hand wheel (if manual override is provided for the valve). So check if it is so and release it.

I could perceive one more reason for non-opening of such valves, that is high pressure differential across the valve. Pneumatic actuators may not operate if differential pressure is more than rated, particularly when pressure in down steam of valve is to be balanced before opening.

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#6
In reply to #4

Re: About PSA Pnuematic Program Valve Maintenanc

08/16/2011 3:57 AM
  1. Turn off Caps Lock.
  2. Change-out the valve for the stock spare. Check the problem has gone away.
  3. Have the faulty valve on the bench, strip it and test it until the fault is found. It certainly cannot be seen from here.
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#13
In reply to #4

Re: About PSA Pnuematic Program Valve Maintenanc

01/05/2024 6:55 AM

Consult a qualified local Instrument Technician.

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#7

Re: About PSA Pnuematic Program Valve Maintenanc

08/16/2011 7:04 PM

Friend,

Here in our plants we have a PSA used to produce nitrogen, The PSA has six butterfly valves from the Mapag people and two valves from the Coax people, the outlet is regulated by a Valtek globe valve. The matter is that these valves are working continuosly during each step of the PSA, this mean that every minute of the day the valves are closing and opening in order to get the final product (nitrogen) in the outlet, it mean the system is cyclic. Therefore all its components (valves / solenoids valves and more) are working/switching a lot of times during the year.

This is one main cause of the failure to open.

Maybe, in your case can be possible that there is any condition present in the PSA that stop the sequence. I could recommend test each valve individually and later test the complete system in order to can detect any problem.

Particularly in our case, the fail in the butterfly valves is due to the lost of seal in the body/disc ensemble, this is caused by the o-ring wear caused by the constantly moving of the disc. In other case the solenoid valves are presented problems due to the presence of liquid(condensate) in the instruments air causing operation problem in the solenoid.

In resume, all is caused by the continuos cycles necessary by produce nitrogen.

The good question is "What can we do in order to reduce or minimize these failures?"

I hope this help

Regards

JP

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Guru
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#8
In reply to #7

Re: About PSA Pneumatic Program Valve Maintenance

08/17/2011 12:18 AM

"the fail in the butterfly valves is due to the lost of seal in the body/disc ensemble, this is caused by the o-ring wear caused by the constantly moving of the disc. In other case the solenoid valves are presented problems due to the presence of liquid(condensate) in the instruments air causing operation problem in the solenoid."

You have to differentiate between valve proper and its solenoid operated pneumatic actuator. lost of seal in the body/disc are connected with valve proper and o-ring wear is for actuator. You have rightly pointed out one of the major cause as liquid(condensate) in the instruments air causing operation problem in the solenoid. Ensure dry instrument air of at least -30 deg dew point. Otherwise why don't you try to use nitrogen in place of instrument air which may be produced dry. But for using nitrogen consult for safety of use, it can be used easily for open air installations.

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#9

Re: About PSA Pnuematic Program Valve Maintenanc

08/17/2011 1:28 AM

sorry for the caps guys..well i tired to analyze also the weather..

when it rain i fail..maybe you think its grounded on its wiring? moisture affect the actuator valve steam to open ups..or i get stuck..

what do you think

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Guru
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#10
In reply to #9

Re: About PSA Pnuematic Program Valve Maintenanc

08/17/2011 3:41 AM

No, Opening of actuator stem may not be affected by moisture. But moisture may affect wiring of solenoid. You can think of providing canopy over solenoid to protect from direct rain.

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#11

Re: About PSA Pnuematic Program Valve Maintenanc

08/17/2011 8:09 AM

there is a valve stem at the diaphram head right? where in it is connected direct to the valve? thats the stem im talking about ^_^ dont the right term for it thats why i called it stem of diaphram..correct me if im wrong thanx!

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#12

Re: About PSA Pnuematic Program Valve Maintenanc

08/20/2011 9:20 PM

Friend,

Please, Can you tell us the valve type, actuator type, brand, model? Butterfly, globe, ball or which one?

Solenoid valve brand, model, type ( two/three/four way)?

My friend pritam the o-ring wear is ubicated in our case in the body/disc ensemble. Our actuators has installed o-rings but there are not present problem yet.

Regards

JP

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