Can you identify this coalescer and auto drain system? Trying to rebuild.

[tmassey]

Uh oh, more auto-drain issues.

So the next time I ran the compressor, I tried to watch the pressure gauges instead of listening for the drains. Once again, when I start the compressor, the drains activate for 8 seconds, then close. Great: at least that's working. Then I watched the gauges. Once again, I can't see that the pressure ever drops like I expect it to. OK, fine, I'll use the wheels for the moment. I also dug out a multimeter to see if I can see what's going on with the solenoid timer, but the timer leads have plastic covers and there's lots of exposed 220V in the box and I don't really want to mess around too much while it's on, so I'm having a hard time getting a good measurement.

After about 30 minutes my tanks are full, so I decide to power off and unplug the compressor so I can work safely in the control box. I rig up a way to measure the signal and restart the compressor. 8 seconds of drain (as expected) continues *past* 8 seconds (not as expected) -- and it doesn't stop! OK, so I hit the big red button. Make sure everything is set up correctly, wheels are closed, etc. and start up again: same thing. Drains don't stop. Uh oh, now what've I done?

In the back of my mind I wonder if gunk has clogged something, probably the solenoid. I noticed when I re-connected the control gas tube, the plug I removed was quite gunky. The plug was at the bottom of a T at the bottom of the coaleser, and I suspect that there was 5 years of coaleser gunk sitting at the bottom of that T which has now tried to make its way through my newly-repaired auto-drains. But I'm *not* about to start tearing things apart when I just paid someone to fix it...

So, put in a call to Poseidon Air. Over the next week of back-and-forth, we try a few things. The most interesting things he has me do: Remove the wheels (back the wheels all the way out and use a 17mm wrench on the nut behind them) and check the tips at the end of the stem: they're all in place and undamaged. Remove the coil and put a screwdriver in the hole and make sure that the coil energizes (it attracts the metal screwdriver) and *stops* energizing: which it does.

The final thing he has me do is use the hex flats on the solenoid stem to remove it from the body of the drain (not the screws that attach the whole assembly). As soon as I do, I see a healthy amount of crud on the solenoid soft seat. The orifice has a little crud as well. OK, obviously gonna have to clean that up.

So I soak the the stem assembly in hot water and Dawn, and use Q-tips to clean out the orifice area. I also remove the control gas tube and soak it in hot water and Dawn, and use some pipe brushes to clean out the tube *and* the T as best as I can, too. They both have a fair bit of crud in them, but seemed to clean up well. The solenoid stem and orifice cleaned up quite nicely.

One thing that's not great: the seat has quite a set. It's probably 1/16" deep or so now, and it started its life out flat. It turns out that these seats are one of the parts in very short supply... so we'll see how it goes with just cleaning it.

OK, now that everything is clean, I put it all back together, and push the button... 8 *really* long seconds while it blows down... and then it stops! Yay!

I don't have time right now to run the compressor, so I shut it down after a few seconds. So far, so good: I seem to have auto-drains that at least *close* like they're supposed to...

Tomorrow I have to fill some tanks, so I'll run the compressor. Hopefully, I'll finally see if the drains are engaging like they're supposed to...

Here are some more photos for those keeping score at home: orifice and seat before cleaning; and the stem and seat after cleaning.

In the photos, you can see the "set" (or well *beyond* set) that this seat has. It seems to seal, but it would be nice to be able to replace it. If I can't get an actual OEM seat, I may have to consider making one of my own. I know I've read posts from others (@rsingler. @Couv and @Bob DBF come to mind) about making seats from generic material. Given that this is not a life-support application, I'm up for it. I know the general idea is "punch out the right size disc of rubbery material and shove it in", but that ignores a lot of details, of course. Does anyone have any suggestions on how I might pursue this?

 

[Gone for diving]

Can you peel it out and flip it?

I have made seats from layflat hose,( like red fire hose,) hard plastic,
rubbery gasket material,
I have even used glue gun, and
Epoxy,
Also you can get silicone hot pads or gloves and try that...
Also have used orings

 

[Couv]

Does anyone have any suggestions on how I might pursue this?

@tmassey I'm new to compressors and do not have an auto drain system on my unit. However, if I needed a seat like you have-and it is a press it, I'd find a used MK5/10 seat and shave/sand it to size.

 

[tmassey]

More auto-drain nonsense: tl;dr: timer seems to not work, and my muffler leaks noticeably.

Now that my drains seam to seal properly, let's see if they actually *work* without intervention. You konw, *auto* drains!

Short answer: nope. The drains open for the initial blow down, which I have now timed: 11 seconds. After that: no blow down. I have verified this by sound, by watching the inter-stage gauges, by multimeter on the load leads, and by removing the coil and putting a screwdriver in it. There is the initial blow down and no more, and I've carefully watched and waited as long as 18 minutes, operating the drains manually during that time, of course.

I unscrewed the timer out of the control box, thinking that there might be an adjustment that could be made. Nope: it seems everything is potted, and there's no knobs to turn. So I'm guessing that there's something wrong with the timer. So now I need to figure out how to address this.

I'm having a hard time finding something to replace it with. Either these external timer boxes (it's a little plastic box maybe 2" square, 1/2" thick) are not common (most timers seem to be integrated into the solenoid itself now?), or I'm not searching for the right thing, because I haven't found anything that looks like a direct replacement.

In the immediate term, I may try to temporarily wire in a momentary N/O switch. If nothing else, I would like to confirm that the drains *will* work correctly if they're asked to, and for another it's less cumbersome than using the wheels. But if there's an affordable direct replacement, I'd rather just do that instead of getting too clever.

One more thing: the muffler leaks like a sieve. If I open the wheels too much (especially the third stage one), I get water spray out of the top of the muffler, seemingly through the filter. So I don't do that. But even if I'm careful and only gently crack the wheels, I get water spray out of the seam in the green top. (See DrainAndOutput.jpg in post 7). I'm guessing this shouldn't happen?

When I had the auto-drains off, I took the opportunity to clean out the muffler. Nothing seemed to be cracked or worn. I noted that there is not an o-ring to seal the green top to the glass bottom, and the connection is a bit loose. Is this correct? Is there something I can do to stop this from spraying oily water all over the place?

So, I think right now that the auto-drains themselves work; but now I have problems to address upstream (the timer) and downstream (the muffler).

Ah, the joys of compressor ownership...

 

[Gone for diving]

Don't know anything about those timers...
But is there some type of signal that tells the timer to start... like a oil pressure signal...
Just guessing...

 

[tmassey]

More information, but no real progress yet. The best part is: I ran my compressor yesterday without any mechanical issues and only straightforward functional issues. tl;dr: the drains work fine, but for now I have to trigger them manually using something like a switch. The muffler needs o-rings it does not have. Waiting on parts to hopefully resolve this.

More details, for those bored with life. Spoke to Poseidon Air: he does have a replacement timer. Also, the muffler is supposed to have o-rings, and mine does not, so of course it leaks. I will need a rebuild kit for the muffler. However, I haven't received them yet.

In the interim, I've rigged up a kind of switch on the solenoid (a jumper wire, really) and used that instead of using the manual wheels. With that, the auto-drains fire properly, so once the timer is replaced the drains should be squared away. Hopefully the missing o-rings will work just as well.

(ETA: To answer @Rol diy 's question: there is no other signal involved. The box only has three connections: common (Black, wired to both solenoid and supply), load in (white, wired to supply), and load out (white, wired to solenoid). I'm pretty certain it's just a relay with something to trigger it periodically, and given its 1980's heritage, I'm not even sure it's as clever as a 555 timer, but certainly not more involved than that.)

In the interim, I've been looking for alternatives. Given the cost of what I had found (like $150 or so), I had originally thought I would wire up an Arduino with a relay board (and use it for temperature monitoring as well), but while exploring that space I found this handy device:



It's darn near perfect: among its many options you can set it to fire for X seconds, then close for Y seconds, and repeat that forever. Turns out there's a zillion devices like that, but this one actually can power itself directly from 240V, which makes it a nifty direct (functional) replacement for the failed timer. If I can't get the timer from Poseidon Air, I will order this guy. It's not a perfect direct (physical) replacement, but there's plenty of room in the box for this guy, so it should work very nicely.

About the solenoid seat: I appreciate the suggestions. Given that it seems to be sealing well at the moment, I don't really want to start prying on it (to see if it could be flipped, for example) or coming up with DIY alternatives. But again, I appreciate the suggestions: if I need to pursue this, they will come in handy. I'll ask Poseidon Air the next time we speak if the seat can be flipped: I imagine if it were that easy he might have mentioned it, but I'll ask anyway.

I have to say, it's really nice to have things back up and running, and not having to mess with valves in the back to drain the compressor. I can't wait to fix the timer and really put the function of draining the compressor out of mind for good -- or at least for a good long while.