Upgrading air compressor regulator

[tpolley]

I've got one of those 29 gallon, belt driven central pneumatic air compressors from harbor freight. It has served me well over the last 10~ years. It will keep up just fine with my occasional wrenching. But something that's always been nagging at me since I bought it is that if I want 90psi when my impact is running, I have to set the regulator to 120psi static(?). It seems excessive, and it causes a pretty significant drop when I squeeze the trigger.

Over the weekend I changed to Milton 3/8npt V style fittings on the hose and the impact. No noticeable change. It occurred to me that I used the same 1/4npt fittings on the gun and 3/8 hose with 1/4npt fittings 20 years ago when I used the gun at a tire shop and I didn't have that issue. Plus if I start changing fittings, I'm going to have to buy a lot of fittings, or make a pigtail adapter. Either way will be a pain right in the ***.

I read/heard somewhere that these budget air compressors use regulators with a low flow rate. So I'm thinking about swapping the regulator with something with more flow. What do I look for when I'm buying a new regulator? Can somebody point me in the direction of a better flowing regulator that won't break the bank?

 

[Citation]

You might be fighting more than just the regulator. On many compressors the outlet air goes into a manifold on the bottom of the pressure switch. That can be an additional flow restriction. Due to a failed tank I rebuilt my belt drive, 20 gal (now 26) compressor. When I rebuilt the thing I installed an aluminum block 3/8" manifold right off the tank outlet. The pressure switch with blow of valve and two outlets (each with a shut off valve) come off that manifold. With this the small T block on the bottom of the pressure switch isn't a flow restriction.

As for my regulator, I got a 1/2” inlet, Chinese regulator with filter off Amazon for something like $25. Seems to work well. Minimal pressure drop when using my impact. I did not want such a large regulator hanging of the manifold so I used a 2' whip from HF to connect the regulator to the manifold. The regulator is attached to the compressor's motor plate. If I moved my compressor around I wouldn't like the regulator placement. I'm my case the compressor is stationary. One outlet is available at the compressor while the other feeds a hose that was run through the rafters to the opposite corner of the garage. It's a very poor man's air system.

 

[redmondjp]

Just eliminate the regulator completely, or have a second compressor output that is regulated for lower-flow tools. You'll be amazed at the difference in performance that it makes. Yes you can run them on higher pressure with no issues - a lot of shops do.

 

[u2slow]

I removed my regulator and added quick-connects to it. That way I get all the air the 1/4" npt stuff on the comp can give for my big gun, and I add-on the regulator inline when using lesser tools.

 

[tpolley]

Okay, so after reading your comments, I decided to add an unregulated fitting before the regulator. I built one using some brass fittings. The one on the left is from the compressor, it went between the outlet on the tank and the regulator/manifold. The one on the right is a replacement with an air fitting. That way I can keep the original regulator, pressure switch, and bleed off valve. I forgot I have a wall mounted regulator/dryer in my tool box that I'm not using. Maybe it will have a better flow?

 

[FredWanaker]

anytime there is a restriction pressure will fall across it when in use. Example using a water system. we have 95 PSI water pressure at the main. The WATTS PRV drops it. When no water is flowing the pressure is 58 PSI. If a small sink faucet it opened it falls to maybe 55 PSI. If a bathtub is opened it falls to maybe 50 PSI. If every faucet in the house and hoses outside are opened it falls to maybe 45 PSI. That is the same with the air compressor. The more volume of air you use the more the pressure drop across the restriction there will be. It is the same in electrical circuits too.

You can turn the compressor regulator up to wide open and add another more expensive regulator on a wall or something with your moisture traps, and set pressure there, or you can try to find a better quality regulator that fits your compressor. If the restriction is the line out of the tank, then that would need to be increased too.

 

[mikedodge]

I use my compressor without a regular and have small ones at the equipment that needs it. I have a regulator with connectors on either side in case its ever needed for something else but I don't remember when it was used last.