Two compressors question

[Wet Spot]

I'm taking delivery tomorrow of my new 60 gal Quincy 2stage air compressor. My old smaller compressor still works and I planned on using it as aspare. My new compressor has a max psi at 175 and I bout a regulator and filter to regulate psi. When adding my spare into the line, should it be T'ed in before or after regulator. I ask because I think it only has max psi around 125 or so. I planned on setting regulator around 100 or so, would that be alright, I currently don't run one with small compressor, I just didn't want 175 down the line.

A second question, I'm asuming the larger compressor should fill first and be used, preventing smaller one from running, but only if large goes out. How can this be fixed if this isn't the case.

Thanks in advance

 

[Rudy]

I have two compressors....a good one...and a cheap one. The tanks are connected together. The cut in on the cheap compressor is set to "not run" as long as the good compressor runs. The only way I know it still works....is when I purposely trip the breaker on the good compressor to test it.

By connecting the two tanks....you've effectively doubled your air storage.

BTW....this setup saved me last week. The good compressor had a piston ring crack (after 10 years of flawless service). It still pumped, even with one piston, while awaiting parts. I felt secure, knowing that the cheap compressor would kick on if the good compressor finally gave up......

 

[mrfixit]

After the regulator. U don't want 175 to a 125 tank.

I would set the new tank to cutoff at 170 or so, regulate down to 110-120, then tie spare tank in set to cutoff pressure of 110 cut in at 90-100 depending on line drop under load. So if pressure drops below 90-100 it will kick on to run and maintain pressure to 110. They have a range that can be set kick on and kick off. Balance them all so the old compressor doesn't turn on unless the new one is down.

 

[wash4me]

There's no need to run that high pressure at the carwash. It will make extra condensation in the lines from the heat and unnecessary wear. I would turn the new one down to 125, tie the tanks together and turn the old one down low enough that it doesn't start unless it drops 10 pounds below the start point on the new one.

 

[2Biz]

I would think you would tie the old compressor in after the regulator on the new compressor. (Lower Pressure). To help protect the tanks/compressors, why couldn't you put CV's on each tank to protect one if the other tank/compressor fails. I've had a pop off open and not reset. The compressor and motor was smoking hot when I got there, obviously not keeping up. But if you have two tanks tired together and this were to happen, a CV on each would keep from damaging the remaining compressor. The CV's would allow the running compressor to maintain system pressure without the damaged one dragging it down. Wouldn't that work?

 

[MEP001]

The tanks of both compressors will have a pressure rating. If they're rated the same, it won't hurt a thing to just tee them together. If the older one is lower, I'd isolate it with a check valve AND put a regulator on its outlet. Make sure that regulator will bleed off the air downstream, and if that check valve doesn't seat 100% the regulator will protect it.

I bought a backup compressor that would fill to 140 PSI when the main one filled to 175. I just tee'd them together and lowered the main one to come on 5 PSI before the smaller one and shut off at 145.