I had an idea that seems solid in theory, but I wonder if anyone has ever tried it.

It seems that if you were to take the output of two compressors and plumb them into the same shop air system, they could work together to add flow and reserve volume.

My thinking would be to connect both compressors to my shop air plumbing with a shutoff valve to each compressor. When I need more volume, like for sand blasting, just open both valves and let the air flow. I expect that one compressor will cut on before the other and if there is light demand, the other compressor may never come on, but if there is heavy demand, the pressure will continue to decrease until the second compressor comes on.

Again, has anyone ever tried this?

 

I've done it using 1 gas and 1 electric compressors. I set the low pressure start on 1 10 psi lower than the other. So the lower stage would only start if the other one could not keep up. I used 1 shut off valve, and a quick coupler so I could remove the gas when not needed. Works great, use it when I start painting.

Just make sure both compressors tanks have sutiable pressure rating. ASME certified tanks generally have a higher pressure rating. If the compressors hav eht same output pressure your fine. If you have one that runs lower pressure need to check the tank rating.

 

we have two compressors connected together at work and they work fine

 

Thats how we run the setup at the plant, is 3 huge screw drive air compressors piped together, and then one smaller (still huge) 2 cylinder pump to do maintence. works great.

 

Well, I got another compressor today and began building a sturdy shelf above the new one to hold the old one. This will save valuable floor space in my hay barn converted to car shop.

The old one is 2HP, 20 gallon, 6.2SCFM @ 90 PSI. The new one is 3.2HP, 60 gallone, 10.2 SCFM @ 90 PSI. I fully expect that the cut on pressures will be quite different, but I will readjust the old one if I have to.

I expect to have them mounted and wired tomorrow and plumbed next weekend barring interruptions. I will report results.

 

IT WORKS GREAT!!!

I got everything hooked up and pipes run today. I have a few more drops that I will connect later, after I get money for a coalescing filter and a larger regulator for that drop. I will do two other drops later, one at my lift and one at the front of the shop near my tire machine.

I turned off the ball valve on both compressors to isolate them from the air lines and let them both run until they kicked off. I then turned on both ball valves to check the system for leaks. With both compressors connected and power available I opened both 3/4" condensation drains which blew out lots of air in a hurry. The big compressor came on first as I suspected it would, then the small compressor kicked on. I then shut off both condensation drains and the small compressor kicked off first, then the big compressor caught up and kicked off. The little one is the last one to kick on and the first one to kick off as I expected.

I turned off the power switches on both compressors and turned off the ball valves on both compressors. I will check tomorrow to see if there is any pressure lost which would indicate plumbing leaks.

Now if it will just make enough to run an HVLP, my plan will be successful.