Silentaire 24A Replacing Regulator



A friend gave me a Silentaire 24a-50. It was 15 years old and had water in the tank. So, of course, the tank blew a hole on the first use.

At this point, I've replaced all the hoses and attached the compressor to a new tank. Changed the oil. And gave it a once over.

The regulator was bad, leaking badly. So I got a regulator on Amazon from TC-Global. But the compressor won't turn off. That is, I've got no leaks, but the compressor keeps running.

When the compressor reaches 40psi, a little hissssss starts from the regulator. I can turn the dial higher (say 50 psi) and no hissss. Until the pressure reaches 50psi.

What I think is happening is that the regulator is for a smaller compressor, say 1/6hp. So the Silentaire is putting out more pressure than this regulator is made to handle, so there is no feedback to the compressor to stop.

While I have been airbrushing for only a year, my math/science skills are high. So I can understand the physics, but I must be missing something.

Does anyone know the specks of the Silentaire regulator, or is the one I got defective? Likely not, I just think it may not be rated for the Silentaire.

The Silentaire is CRAZY quiet. So if I can make this work, that would be super. Thanks for any help.

I'm a bit confused... you say you have no leaks, but it's hissing. That would be a leak. What kind of regulator is it? Does it have the moisture trap on the bottom? There is usually a drain valve on the bottom - if so, make sure that's closed properly. Other than that, you have a leak somewhere. Did you use teflon tape on the threads?
There are no leaks as long as the pressure is below the regulated setting. Once the pressure reaches the regulator setting, then there is a hissss from the regulator. Teflon tape everywhere. It's a regulator from ZeroPoint. Rated at 135psi, (I looked it up after my post). One reviewer mentioned that he needed to take the whole regulator apart and clean it. So maybe I should do that. Yes, it has a moisture trap. I suspect that the regulator has a part that is not screwed in correctly. I'll try that tomorrow.

So, for us newbies, is the idea behind the regulator that it shuts off at the selected pressure. Thus the compressor will still fill the tank to it's (the compressors) maximum pressure. So if the Silentaire has a max of 100PSI, it will reach that pressure in the tank. The regulator will only allow 40PSI (or what ever I set it for) to pass to the airbrush. Do I understand this correctly?

To the best of my knowledge, that is correct about how a regulator works. You might be able to spray some soapy water on the regulator to determine where the leak is occurring? I'm not very familiar with the internal workings of regulators... but sounds to me like something is either defective or improperly assembled. I'm also a bit curious what's wrong with the original regulator. I do suppose that something could wear out or fail due to age or non-use.
The original regulator had chunks of black grit - I suspect the "O" rings had deteriorated. I still have it, but there was a leak from that also. But it was in a place the looked unrepairable.

This compressor retails for $1,000+, so a $20 regulator, a $68 tank and $30 in hoses and connectors was well worth it.
The tank is also 10Gal vs the 6Gal it came with. At $100 or so, I can't get a 40db (super quiet), 1/2 HP compressor with this much power. Here are the specs on Azon:
  • Output: 2.15 CFM
  • Max Pressure: 114 PSI
  • Operating Pressure: 84-114 PSI
  • Noise Level: 40 Decibels
  • Tank Size 6 Gallons
It's a 1/2HP. Not that I need all that. The most PSI I'd use is 50. My other compressor is a Cool Running 1/6hp, 47db:
Master Airbrush Model TC-40 - Cool Runner. This is tankless, but I added a tank after the compressor. This just uses a standard airbrush hose to a 10 Gal tank. The tank has a "T" connector, were the other end goes to my airbrush. So this acts more like a bladder. The compressor supplies air to the tank, and shuts off when the tank reaches the max pressure set on the regulator just like when your airbrush is off.

My Silair is setup more like a standard compressor, where the regulator is after the tank's output.

Anyway, I think I'll take the regulator apart and see what may be loose.

The compressor should have a pressure switch on it that shuts off the compressor when it reaches the max pressure! The regulator controls pressure being let out of the tank! With a leak in the system the compressor never gets to the max pressure so it won't shut off,sounds like you have a bad regulator, you can get a new one at the auto parts store and send the one you have back and get a refund
Not sure on your compressor but some have an adjustable pressure switch so you can set the low pressure on it (when the compressor turns on)
And set the high pressure for when it turns off
There is no Hi/Low pressure adjustment. And I do not think this compressor has a pressure switch. That said, I do see a little tube the runs from the compressor to the switch. That might be a feedback to the switch. I'll look at the manual.

I did find the leak is at the regulator. It's from the water trap. It must be missing a o-ring or needs teflon tape.
Repair the leak and see if everything works right!if you have a tube going to the switch its a pressure switch of some sorts
Well after five leaks, the tank hold 115PSI for five hours. I used some plumbing goop on ever seal that was leaking. Teflon tape was getting eaten by the oil. I think there was some oil on the fitting holes from the machining process. That or the compressor is letting some oil into the tank with the air. When I unscrewed each leaking connector, the teflon tape was all gooped up. The plumbers goop, seals much better and I did not need to crank the connectors so hard to achieve a good seal.

After using the plumber's goop on one seal, I could hear a hiss on another. Three seals were fixed with the goop. The other two just needed a little tightening.

So now I have this super quite Sil-Air (40db) and 115psi compressor. Hooked to a ten gallon tank, all mounted on a home-made, wheeled cart. The output goes to my old ten gallon tank (for a total of 20 gallons of air. All that is connected though three manifolds to ten airbrushes. I was amazed yesterday after I quit for the day. Five hours later ... I still had 40psi in the tanks.

So my frustration project paid off. This compressor would have been $1k new. Now, with $100 new tank, and some hoses ($30) and a lot of frustration ... I have this all working. If I paid myself for all the time, it might have been $350. But it was a great project to revive a great, old but working, compressor.

Thanks all for your help!