Moisture in tanks; measuring humidity

[rjack321]

DO NOT rotate filters. The downstream one is not "pristine". There's plenty of crap in it. As it loads up with different contaminants in position 1 it will start to liberate some of what it filtered out earlier and that will move into filter 2. This has the net effect of loading filter #2 with contaminants prematurely and negating the whole point of having a 2nd filter to ensure clean gas.

Its ok to change filter #1 on a shorter schedule, its not ok to reuse a partially filter in any position and think that its doing anything useful. In fact its probably just moving contaminants around the various filters beds that you should really just be throwing away.

 

[fppf]

For starters most systems don't have the same cartage type in both towers. CO reactor and Active carbon don't work well when there wet.

Second by by "rotating" IE moving second filter to first stack and only replace the second filter you can reintroduce contaminates into the air supply. Per LF
"Timely maintenance and cartridge change is one of the
most important considerations when operating a purification
plant. By all means, sound practice and care go a long way
towards ensuring a good outcome; i.e. safe breathing air. A
common mistake is seen in swapping (or rotation) of adsorbent
cartridges in a multi - tower system. This appears to be a cost
saving tactic while in fact it could easily jeopardize the air
quality by reintroducing contaminants back into the air stream."

Filter cartage's are cheap in the grand scheme of things, don't skimp out here. Its just not worth the risks.

 

[Doc Harry]

Maybe the mositure isn't from the compressor. Maybe the cylinder valves are still wet when you connect the fill whips. That would blow water into the cylinders.

 

[fire_diver]

That wouldn't explain why the filter media was physically wet after only 5 hours of operation.

 

[Doc Harry]

That wouldn't explain why the filter media was physically wet after only 5 hours of operation.

Oops! I read through the thread but missed that part. You're right.

 

[veriqster]

I stand corrected, my bad, you guys make some sense, sorry.
I wish you would tell this to people that have ONLY ONE filter to rely on, since they have to breathe that crap that is being "moved around", especially the ones that buy such a system being convinced by manufacturer advertising that they are getting "the best that is available on the market".
I personally have two identical filters that are mounted in the stack and I do rotate them. I have plans to mount a P1 after them and load it mostly with activated carbon (some hopcalite too, no desiccant), just didn't get to it yet.
My take is that if ONE filter is good enough to provide grade E air than having the second one is just a contingency, an insurance for when things go wrong. I do repack BOTH filters beginning of the season. I'm yet to send my air in for analysis but from the looks of tanks I can tell it's WAY better than some air I used to get from various diveshops.
Should I change my setup and start using the first filter as desiccant only? Where should the moisture indicator go in this case?

DO NOT rotate filters. The downstream one is not "pristine". There's plenty of crap in it. As it loads up with different contaminants in position 1 it will start to liberate some of what it filtered out earlier and that will move into filter 2. This has the net effect of loading filter #2 with contaminants prematurely and negating the whole point of having a 2nd filter to ensure clean gas.

Its ok to change filter #1 on a shorter schedule, its not ok to reuse a partially filter in any position and think that its doing anything useful. In fact its probably just moving contaminants around the various filters beds that you should really just be throwing away.

 

[fppf]

You don't want to guess on this.
Filter design is based on the capacity and type of compressor you have. It is also based on environment your pumping in.

I would really call LF, they can easily and professionally recommend a filter setup that fits your needs. And good god man, get your air tested. You should have a new setup tested before you use it. "My tanks look clean" is not a way to test if the filters are working. CO, CO2, and other hydro carbon combustion by products can't be seen, tasted, or smelled.

 

[PhilEllis]

I'm yet to send my air in for analysis but from the looks of tanks I can tell it's WAY better than some air I used to get from various diveshops.
Should I change my setup and start using the first filter as desiccant only? Where should the moisture indicator go in this case?

In my opinion, the second filter in a dual filter system is not a "backup" or "safety" filter.....it is simply a part of the filter system. I think the best practice is to have a first filter that is desiccant only, with a second filter that is a triplex filter. The addition of the hopcalite provides for carbon monoxide conversion should any reach the filter. The two filters are simply parts of a total system, and as such, should be changed together. Anyway, just my opinion.

Phil Ellis
Discount Scuba Gear at DiveSports.com - Buy Scuba Diving Equipment & Snorkeling Equipment

 

[veriqster]

Should i move the moisture indicator after 2nd filter in this case or leave it after the first and just change both filters at first sign of moisture in the air?
The filter system is pressurized at about 2000 psi by means of back pressure valve.
I know what you are referring when you say byproducts of hydrocarbons, that should not be the case - I can keep my hand on any of the heads for quite some time when the compressor is running, there's just a shine of oil on the top of the canister with the "separator water", the oil pressure is in specs. Currently the filters are both packed with desiccant, hopcalite & activated carbon.
I guess I'll add that P1 ASAP just in case, better safe than sorry.
P.S. funny how I had no incidents, no reasons to worry and now I'm kind of tempted to just go get my fills from the shop, all after a simple discussion over the internet. I hope / guess this will go away.

In my opinion, the second filter in a dual filter system is not a "backup" or "safety" filter.....it is simply a part of the filter system. I think the best practice is to have a first filter that is desiccant only, with a second filter that is a triplex filter. The addition of the hopcalite provides for carbon monoxide conversion should any reach the filter. The two filters are simply parts of a total system, and as such, should be changed together. Anyway, just my opinion.

Phil Ellis
Discount Scuba Gear at DiveSports.com - Buy Scuba Diving Equipment & Snorkeling Equipment

 

[CraigAClark]

Sight glass indicators (visual monitor) are what I refer to as a fail safe. If the element(s) change color, they are indicating that a problem exists. If you think about it, the gas that caused the color change had to pass over the element(s) in order to effect the change. That means the gas has moved on down stream and has contaminated what ever it has come into contact with. If oil vapor passed down stream, it isn't a simple matter of putting new filters in to correct the problem. You will have to actually clean the surfaces of the contaminated items.

Craig