Filling and Humidity

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I have a CO meter on the output. I have a regulator on the output and a flow control feeds a steady low rate to my output O2 sensor and to my CO meter. I suspect a dew point meter capable of testing air as dry as scuba air would be expensive.
I was also thinking that those meters would be expensive, which is why I am looking into the eyeball thing.
 
I was also thinking that those meters would be expensive, which is why I am looking into the eyeball thing.
I don't use my compressor very often. The display slowly goes pink over time (It is the 3 section one and the sections are different shades of pink and blue). If I fill all my tanks, a couple of days of running or more, the display goes to fairly blue. I'm sure a big shot of humidity would change it faster to pink, but I don't think really dry air will rapidly change it to blue.
 
I was also thinking that those meters would be expensive, which is why I am looking into the eyeball thing.

I have a very similar setup. I use a ToxiRAE 3. I paid $200. They’re closer to $300 now. In the world of scuba compressor costs, it really isn’t that bad. RAE Systems ToxiRAE 3

Others use the Sensorcon. It’s quite a bit cheaper: $130 or so. Portable Carbon Monoxide Detector Meter (CO Inspector)

To do it right, you need a few more parts in addition to what BRT described: bump gas and a regulator. Here’s a post with some of the details of mine: Source For Replacement Sensors in the US and Elsewhere. Check out posts 15 and 18.

I’ve been very pleased with the electronic meter. It absolutely has detected carbon monoxide when I was running the compressor: my wife was mowing the lawn. Even just the mower quickly passing by the intake brought in enough carbon monoxide to alert the meter, and I was able to resolve the situation before detectable carbon monoxide appeared in the tanks. To me, that alone makes it way superior to the passive eye, and justified the cost with that single incident.
 
I basically have 3 questions here today:

1 - The moisture disks are rated in relative humidity. What percentage is considered acceptable? I see that -50 dew point is specified some places for what scuba air is supposed to be, but I don't see how that translates to RH in the eyeball gizmo.
2 - When you put a new filter in the stack & the air gets dry again, does the moisture indicator change back to blue? or do you need to replace the disk?
3 - when the CO disk turns dark, will it clean up again when it sees clean air, or does it need to be replaced?

I'm trying to decide if I should buy one of those eyeball things, so I'd like to get an idea of how they can be properly used & relied upon.

Thanks

I have one inline... I never look at it and it doesn't really serve any purpose. Currently mine is an off white, slightly blue color. My tower stays under pressure all the time @ 2200psi+, my filter isn't old. It's just not as productive as I thought it would be. Maybe if I used my compressor more (which is maybe twice a month for 2-3 hrs?), idk... maybe it's something you should have, but you're hoping you never really have to use?

So to answer your questions

1.) I was told any humidity was unacceptable. If you've gotten to that point you've already used up your filter. Really shouldn't get to that point. If you do get a disk get the 10/20/30.

2.) I was told it should, but might take a while. Ideally, you don't want to wear a filter out like that. Better to be safe than sorry and change more often. I look at it like more of a check engine light than the service indicator @ x miles. If it's pink, something bad is going on. I wouldn't use it to know when to change filters.

Someone (@rjack321 I think?) posted that you can use some heat (like hot air gun) and that works almost instantly to change them back. This works well for me. Absolutely no need to buy new. I think he said he's had his for over 10 years now? I had to do that when I 1st set mine up as the moisture in the air had turned mine pink.

3. I do not have a CO monitor disk... I was told it was pointless as when it does give you any indication that's already too much. Get a digital one like everyone else linked and analyze after.

With that said, I'm not an expert. My compressor is an oiless Rix, so I'm a little safer from hydrocarbons. Always learning, just passing on what I've been taught... good luck!
 
The compressor I am working with now, has auto drains. The drain system dumps all pressure out of the stack when the system shuts down. Because of this, I am concerned that the cartridge will degrade much faster than normal. I am looking for two things. I am looking for a way to indicate when the cartridge needs to go & I am looking for a way to identify if the humidity is going to put my tanks in danger of corrosion.

My concerns were amplified after watching this video -
About 30 seconds in, the guy explains that their old aluminum tanks rotted out because the compressor was putting water into them. At 4:50 the other guy explains that the compressor has an auto dump valve. At 5:20 he shows his fill log card that indicates they change cartridges every 35 fills (he says a different number, but look at the card, he can't count). That number of fills seems marginal under good conditions & is probably more than optimistic for a compressor that is located in an engine room in the tropics, but may be closer to insane for a system that had the stack drained every time the unit is shut down. I'm looking to not damage my tanks.

I am further concerned that they state they have filled thousands of tanks, but say noting about testing for CO. The rusty high pressure fittings on that rig also scare me.
 
The compressor I am working with now, has auto drains. The drain system dumps all pressure out of the stack when the system shuts down. Because of this, I am concerned that the cartridge will degrade much faster than normal. I am looking for two things. I am looking for a way to indicate when the cartridge needs to go & I am looking for a way to identify if the humidity is going to put my tanks in danger of corrosion.

My concerns were amplified after watching this video -
About 30 seconds in, the guy explains that their old aluminum tanks rotted out because the compressor was putting water into them. At 4:50 the other guy explains that the compressor has an auto dump valve. At 5:20 he shows his fill log card that indicates they change cartridges ever 35 fills (he says a differnt number, but look at the card, he can't count). That number of fills seems marginal under good conditions & is probably more than optimistic for a compressor that is located in an engine room in the tropics, but may be closer to insane for a system that had the stack drained every time the unit is shut down. I'm looking to not damage my tanks.

I am further concerned that they state they have filled thousands of tanks, but say noting about testing for CO. The rusty high pressure fittings on that rig also scare me.

Why would the system dump all the air from the stack, why not install a check valve after the coalescers and before the tower? Cheap and easy.

The 10/20/30 will do what you want, but it would be better to have an hr meter or take notes as you go and have a plan to change at "x" hrs.

Here is from another thread about RH;


From what I gather, you'd want less than 20% (I actually thought you'd want less than this).
 
Why would the system dump all the air from the stack, why not install a check valve after the coalescers and before the tower? Cheap and easy....
The auto dump system is set up with normally open unloader valves on both the primary coalescer & the P0 stack. When power is lost, they open & everything gets dumped. I should probably add manual valves in series so that I can isolate the system when the unit shuts down. The Brownies auto dump system looks to be set up that way. I don't know why the Bauer factory system lacks that feature, but it does, at least on the two examples I have seen so far. One is 1997 vintage. The other was from the early 2,000's, maybe 2005 or so.
 
The auto dump system is set up with normally open unloader valves on both the primary coalescer & the P0 stack. When power is lost, they open & everything gets dumped. I should probably add manual valves in series so that I can isolate the system when the unit shuts down. The Brownies auto dump system looks to be set up that way. I don't know why the Bauer factory system lacks that feature, but it does, at least on the two examples I have seen so far. One is 1997 vintage. The other was from the early 2,000's, maybe 2005 or so.

I can only give experience on my system. I have 2 coalescers, then a check valve, then the filter tower itself. I would never have a auto drain valve on the filter tower. There's no point to draining it down unless I'm changing the filter. Can't that be removed / disconnected? I have a manual drain, but I might open it a hair maybe once an hr, and just a hair. I get very little out of it at all (given, I'm not in FL, no idea what that's like).

I do drain the coelescers down after running the compressor. The only thing that still has pressure when I put it away is the tower itself.
 
The compressor I am working with now, has auto drains. The drain system dumps all pressure out of the stack when the system shuts down. Because of this, I am concerned that the cartridge will degrade much faster than normal. I am looking for two things. I am looking for a way to indicate when the cartridge needs to go & I am looking for a way to identify if the humidity is going to put my tanks in danger of corrosion.

My concerns were amplified after watching this video -
About 30 seconds in, the guy explains that their old aluminum tanks rotted out because the compressor was putting water into them. At 4:50 the other guy explains that the compressor has an auto dump valve. At 5:20 he shows his fill log card that indicates they change cartridges ever 35 fills (he says a differnt number, but look at the card, he can't count). That number of fills seems marginal under good conditions & is probably more than optimistic for a compressor that is located in an engine room in the tropics, but may be closer to insane for a system that had the stack drained every time the unit is shut down. I'm looking to not damage my tanks.

I am further concerned that they state they have filled thousands of tanks, but say noting about testing for CO. The rusty high pressure fittings on that rig also scare me.
A rough rule of thumb is that a P0 is going to last about 3-4 hours in a poor, hot FL boat installation. 35 fills would be like 15 hours which is absolutely too much unless its like 45F in your garage.

"Rated capacity" is highly optimistic and based on a 70F outlet gas temp. Capacity plummets as the outlet gas temp rises. The P0 size BARELY makes breathable quality air under the best of circumstances. And when the media saturates it rapidly exceeds allowable water content. Once the AC and hopcalite are even slightly moist they don't work anymore and you can easily get oil and CO bypass.

The best thing you can do is:
1) Ventilate the heck out of your compressor
2) Add a seawater cooling loop if possible so the gas going into the filter is as cool as possible
3) Add a second larger triplex media filter (16" or 20")
4) Change the primary P0 often - as soon as it hits a solid 20% RH (spyglass between the P0 and the secondary filter)
5) Treat the secondary filter as a backup and swap it out once you've pumped ~75% of rated capacity. It's not working very hard as a second filter but you're not trying to maximize your filter use. You're trying to reliably have breathable gas.

6) Regular air testing right at the end of the filter life.
 
...
I’ve been very pleased with the electronic meter. It absolutely has detected carbon monoxide when I was running the compressor: my wife was mowing the lawn. Even just the mower quickly passing by the intake brought in enough carbon monoxide to alert the meter, and I was able to resolve the situation before detectable carbon monoxide appeared in the tanks. To me, that alone makes it way superior to the passive eye, and justified the cost with that single incident.
Neighbors having a bbq is also good for some CO intake.

There's another way to get alerted of CO leaving your compressor. I used a metal filter housing like the one shown below, but without the filter cartridge. Instead, I filled the housing with hopcalite and placed it on the feed line going from the compressor to the airbanks.
1641255584612.png

When CO is present in the air intake, it goes through the compressor and then enters this filter housing. The hopcalite will start turning CO into CO2 and while doing that, it gets hot. Since the hopcalite touches the metal housing, the housing will warm up as well.
The cheapest (and first) detection is done with a $0.30 temperature sensor that is sensitive enough to measure a 0.1 degree difference.
A processing unit can keep track of temperature rise per timeframe and shutdown the compressor in case the increase is too much.

The second detection is done by letting some air pass through a needle valve / flow limiter and direct it over a ZE07-CO sensor ($10-$15). The same unit reading the temperature can also read the CO sensor and shutdown the compressor in case of 1ppm CO detection.

My experience that in such situations, the temperature alerts me of CO presence in the ambient air, but the hopcalite is doing exactly what it needs to do and no CO passes that filter (but I still shut down the compressor and wait until the neighbors are done).
 
https://www.shearwater.com/products/teric/

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