Motorsports Village

Duelling air compressors
Page 1 of 1

Author:  just primer [ Mon May 28, 2012 11:31 am ]
Post subject:  Duelling air compressors

The first air compressor is a homemade job. The tank is (I think) called iron horse 21 gal. It was a devilbiss oil less unit. I put a kit in it and placed it in a plywood box outside behind my garage. I had a small window for ventilation and a few months later the piston exploded into small pieces inside the box. So a buddy of mine gave me a double piston antique pump from I think the 60’s or seventies and I used the 5 horse motor and made a large plate holding the pump in line with the motor to run a belt. I then built a large duct around the outside of the box with a square foot opening on two sides and two small 8’’ fans pushing the heat from an intake side to an exhaust side and blowing on the pump face and the motor face. It runs so fast it sounds like a motorcycle. The box is lined with one inch foam and I have a 15 watt indicator light inside the garage because I can barely hear it, that way I can see when it is in reboot mode. It reboots in a minute nineteen seconds. 0 to 130 in a little more than 3 minutes. Oil leaks past one of the pistons and I need to rebuild it but it still pumps fast and I have been using it for years without any changes.
The second compressor is a 25 gal craftsman professional that I bought for work to shoot drywall texture. It goes up to 150 instead of 130 and it’s also a belt drive. It’s very quiet but it’s slower than my homemade one. However it works pretty great for a newer compressor. I was able to shoot a full skim coat out of the hopper on several rooms in order to completely cover the old texture, make it smooth and start over with a hand skip trowel. That was hours of running the hopper at full blast in several rooms. I would only let the compressor catch up out of sympathy and it would not get very hot at all. It would even hold the air at close to 100 most of the time.
The question: They both have different shut off pressures. The one with the higher shut off is slower to reboot. Could I plum them both into the same regulator on different electrical outlets. If I place a one-way check valve on both before the regulator. So I can have increased tank size for a DA sander or sometimes I still use an air grinder/cutter because I like the speed control. If the regulator receives two separate volumes of air they would equalize right. At 130 from each it wouldn’t be any more strain on the regulator would it? Of course the slower one would be at 150. What is the best way to do this? Run the units inline?

Just primer

Author:  Beretta [ Mon May 28, 2012 12:13 pm ]
Post subject:  Re: Duelling air compressors

Mr Primer =; ....When I painted my car in the garage I was going to need more air so I borrowed my neighbors compressor. Now his is bigger than mine 20 to 50 gallon but only 50 psi difference...So I hooked them together with one air line and it worked out real good...Larger compressor came on
when it called for air and smaller came on when air got down to 125psi..Smaller would kick off and larger one would stay on till pressure got to set level...Does that help?????? =;

Author:  rick360 [ Mon May 28, 2012 12:37 pm ]
Post subject:  Re: Duelling air compressors

The one with the higher shut off is slower to reboot

What do you mean by "reboot"?


Author:  just primer [ Mon May 28, 2012 12:40 pm ]
Post subject:  Re: Duelling air compressors

I had them both on a Tee fitting going into the Regulator last night, and the regulator on the slower one was wide open, but the pressure from the faster one was causing the regulator on the slower one to bleed off air. That is why I was thinking of placing check valves inline. With the term reboot, I mean when it kicks on at 125 to raise it back to 150, or in the case of the faster antique it kicks on at 80 and raises it back up to 130.

Just primer

Author:  rick360 [ Mon May 28, 2012 9:28 pm ]
Post subject:  Re: Duelling air compressors

If the tanks are both rated for the higher pressure you can just tie the tanks together at a T into a single regulator w/o any check valves. Then put an on-off switch on the lower setting compressor and leave it off unless you are doing something that you need more air then turn it on. - That's how I'd do it.

You may also be able to adjust the pressure switch settings, but be careful with that. Make sure you have pop-off safety valves that are lower than the tank rating and will flow enough to prevent overpressure in the event of a switch failure.


Author:  just primer [ Mon May 28, 2012 11:54 pm ]
Post subject:  Re: Duelling air compressors

I may have jumped the gun. I might have just needed to open the regulator completely on the slower tank. If both tanks have the regulator wide open then they are out of the equation right? I just wanted to see if anyone else had done this before. Both of my tanks are in good shape, and the old one is in an isolated box outside of the garage. When I heard the hissing on the regulator on the new one I thought I should check with someone. We have had a man die in a town near by from experimenting with his own homemade compressors. I assume that the tank was crappy and it exploded. I still have all the original safety valves and nothing is rigged on the old tank. The other one is brand new.

Thanks for the responses.


Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group