Moisture in tanks; measuring humidity

[ScubaDemon]

Hello again!

I had some time today to take apart the compressor. I realised that there is indeed an adjustable pressure maintaining valve installed, which wasn't working. I disassembled and cleaned it, and now it seems to do the job again. Now the question is how to adjust it. The manufacturer is apparently annoyed that I fixed it, rather than buy a new one that comes pre-adjusted, and won't give me information on the best pressure setting (or maybe they don't know themselves when they only install pre-adjusted parts?!). Very odd.
What would be the possibly best pressure? I set it to about 130bar now, but I want to make sure not to have it set too high and not damage the 3rd stage of the compressor by permanently maintaining a pressure that is too high. Any suggestions?

Thanks again ;-) Greetings from the desert!

 

[fppf]

NEVER NEVER NEVER swap filters, PERIOD, NEVER

Place a call into the experts for all your questions, they also have lots of reading material for you to read.

Lawrence Factor, Inc. - High Pressure Purification Products.

 

[CraigAClark]

Hello again!

I had some time today to take apart the compressor. I realised that there is indeed an adjustable pressure maintaining valve installed, which wasn't working. I disassembled and cleaned it, and now it seems to do the job again. Now the question is how to adjust it. The manufacturer is apparently annoyed that I fixed it, rather than buy a new one that comes pre-adjusted, and won't give me information on the best pressure setting (or maybe they don't know themselves when they only install pre-adjusted parts?!). Very odd.
What would be the possibly best pressure? I set it to about 130bar now, but I want to make sure not to have it set too high and not damage the 3rd stage of the compressor by permanently maintaining a pressure that is too high. Any suggestions?

Thanks again ;-) Greetings from the desert!

To adjust the PMV, disconnect the line leaving the purification tower (releave pressure downstream from the PMV. Loosen the lock ring (I am assuming that this is an Aqua Environment PMV, gold anodized rectangular block) and back it off several turns. Start the compressor and watch the final stage pressure gauge to see at what pressure the PMV starts to open (the final stage pressure must be taken from the upstream side of the PMV for this to work). Using the correct size allen wrench, turn the adjustment cap either clockwise to increase the pressure or counter-clockwise to decrease. Once set, tighten the lock ring and reconnect the line. Normally the PMV is set to open at 2200 psi. Some applications, like a moisture monitoring system, may require the set pressure to be higher. The higher the setting the longer the dwell time.

Craig

 

[ScubaDemon]

Hello Craig.

This is extremely helpful, thanks. I guess it is not quite the same valve, as it is rectangular aluminium block with a big adjustment knob, but the procedure should be the same.

Thanks!

 

[rcontrera]

Man ... I don't know who got upset with you since cleaning and adjusting is part of normal service. The belleville washers do come as a set and you have to make sure that you don't lose any and put them back in the proper way. But the adjustment is the large cover knob on the bottom. Once you have the pressure set (kind of a tedious trial and error until you find the sweet spot), then tighten the lock nut down onto the knob to keep it from vibrating out of adjustment.

Hope that helps.

 

[veriqster]

NEVER NEVER NEVER swap filters, PERIOD, NEVER

Place a call into the experts for all your questions, they also have lots of reading material for you to read.

Lawrence Factor, Inc. - High Pressure Purification Products.

I understand the logic in behind this statement - it's been a long debate on some forums, ...
my take is that if you don't skimp on chemicals there's a LOT of things that have to go wrong to get you "bad air" in this scenario, or at least that's how I understand things.
going the route you suggest one would buy air all the time and not bother with his own machine or even better, partial pressure blend the air or any other mix he / she uses from lab grade liquefied gases.
just my 2 cents, no intent to start flames.
P.S. you got to know your "filter times" if you pump or you're better off buying the gas.

 

[rjack321]

Hello!

When I prepared my tanks for visual inspection, I found that there was some moisture in some of the tanks. I fill with a Coltrisub MCH16/ETS compressor (under 1000h, clean and well maintained), change the filter cartridges even more often than recommended, and never had a problem with moisture before.
Those tanks are never emptied completely, and our humidity here is quite low (average about 20-30%), even though the compressor station is located near the beach. The compressor has a well functioning auto-drain, and I cannot find any faults in the set-up.

What could cause moisture in tanks?

To avoid problems, I am thinking about monitoring the humidity of the compressed air electronically. Unfortunately I cannot find any components here. What systems are available, and what are the approx. costs?

Ambient humidity will NOT influence how much moisture is getting to the filter. It may slightly influence how much water is discharged by the drains. The first filter will always see 100% humidity at ambient temperature, and at 45C ambient that is a tremendous amount of water.

You need to pump during cooler times or put the compressor into an air conditioned space to make the filters last longer. You could also cool the compressed gas with a chilled water bath before the final condensor, that would force more water out.

45C is really really hot and runs the risk of partial oil combustion. You best choice is to pump at cooler times of the day or put the compressor into an air conditioned space (or both).

 

[rjack321]

I understand the logic in behind this statement - it's been a long debate on some forums, ...
my take is that if you don't skimp on chemicals there's a LOT of things that have to go wrong to get you "bad air" in this scenario, or at least that's how I understand things.
going the route you suggest one would buy air all the time and not bother with his own machine or even better, partial pressure blend the air or any other mix he / she uses from lab grade liquefied gases.
just my 2 cents, no intent to start flames.
P.S. you got to know your "filter times" if you pump or you're better off buying the gas.

You really don't.

Rotating filters is a horrible idea. Don't do it.

 

[Killer&Griller]

Don't rotate filters........... LF clearly states not to reuse them......

Pick a cooler time of day to run the compressor........

Bleed off the compressor at a higher rating or set your compressor to only start filling once it hits above 2k.

DON'T REUSE FILTERS.......

Where is your air intake source coming from? Do you have air being piped in from outside? Is it a hose going up to the ceiling, what?

If you run a fan (on high) in front of your flywheel, you will cool the compressor a bit more which will also help.....

 

[veriqster]

Don't rotate filters........... LF clearly states not to reuse them......

Pick a cooler time of day to run the compressor........

Bleed off the compressor at a higher rating or set your compressor to only start filling once it hits above 2k.

DON'T REUSE FILTERS.......

Where is your air intake source coming from? Do you have air being piped in from outside? Is it a hose going up to the ceiling, what?

If you run a fan (on high) in front of your flywheel, you will cool the compressor a bit more which will also help.....

Just to clarify, I am not talking about rotating filters, I am talking about moving the filter element from downstream filter to the upstream filter and replacing the one downstream; this being done at the time when the air after upstream filter shows any humidity (visual indicator in between filters). Is this a poor practice? Why? (my understanding is that at this point the downstream filter is basically pristine, unless you got CO or other crap coming out of your compressor in abnormal quantities).
I'm not trying to start a controversy but if I AM WRONG I would appreciate if somebody could point me into the right direction.