Plumbing 2 dissimilar sized compressors?

[HTGTS350]

I got a new compressor yesterday as my original was going to be too small to run my new blast cabinet and I need to plumb both compressors together to get enough free air to run the cabinet. My original is an IR 17(290L of free air) and the new one is a Peerless P19(420L of free air) both single phase as that is all I have available. The whole place is plumbed in 3/4 copper but I have yet to decide where to put the blast cabinet. I also have three 106L air receivers to be plumbed in. The old compressor has a 60L tank and the new has 120L. My main question since reading some other posts is will these compressors try to fight each other if I plumb them into a T or Y fitting and have them side by side or should I put one compressor at each end of the system and make the whole setup into a loop?

 

[HTGTS350]

Woops, forgot to mention I would also like to be able to isolate one or the other compressor when I'm not blasting as the small one was sufficient for most of the other work I do. I have about 1200ft of 3/4 copper at my disposal and plenty of fittings ball valves etc.

 

[RECox286]

I would think about putting a check valve at each of the compressors' discharge

or regulated air outlets. Air is easy, hydraulics can be trickier.

Uncle Bob

 

[jimindm]

Several body shops that I have been in actually had two compressor set ups. They had a timer devise on the wall that would alternate the operation of each compressor. If needed, both would run. This was in larger shops with some very big units. Not sure that they make a 110 version of it, if that is what you need. One thing I would suggest if they are 110 and 220 is available, run them on seperate power legs in the panel.

Surly one would run the blaster. I would maybe try to tee the blaster off, so when using it, only one will power the blaster. Is it just you? If your blasting, how much other air would you need?

Without some kind of alternating devise, it would take alot of adjusting to get them to come on and shut off, at proper times, so one is not running most of the time. Not sure I would want them both powering up at the same time. I know you asked about plumbing, but have you thought about the electrical side yet?

 

[jake00]

We've to 2 at work, right next to each other hooked up with a H. Sometimes we run 1 sometimes 2.

 

[HTGTS350]

The blaster needs 680L of free air to run that's why I went with the second compressor, I hope the big compressor will be able to do it most of the time and the smaller one will maybe kick in when it needs to.

 

[rvr6000]

Absent some kind of check valve the pressure between the two tanks is going to be equal....the volume of air will be different but the pressure will be the same. They wouldn't necessarily be fighting each other but you might have to make some adjustments to the pressure switches so they maybe aren't both kicking on at the same time.

 

[sberry]

No check valve between them, you may want isolation valves in case you want to take one out. Set the kick on pressure on the second just below the first, when it cant keep up the second comes on, this type of system uses both tanks for either comp.

 

[Sureshot]

No check valve between them, you may want isolation valves in case you want to take one out. Set the kick on pressure on the second just below the first, when it cant keep up the second comes on, this type of system uses both tanks for either comp.

Exactly. Don't overthink it.

 

[HTGTS350]

That's the path I was going down until I read some of the threads here and elsewhere and thought I should ask, I will turn the system into a loop when I plumb in the air receivers I just didn't want to overstress either compressor as the new is so much bigger than the old and the old has been working for so long.

 

[nehog]

I have two, and when needed (rare) I use a double male stub hose to connect the small (portable 4.5 CFM IR) to the big one. In the center of the stub hose is a simple valve (butterfly) so the air doesn't get out when connecting them. Cost: about $15 for parts.

 

[sberry]

My second runs less than 1%, its a backup, comes on when doing light sandblast of blowing down piping. In my case it smmoths out the run time a bit on the main, 200 gallons of tanks stored.

 

[stonesfan68]

Plumb the output of both machines into a common receiver. Install a pressure regulator after the receiver and set it for the pressure that you need. Buy a good pressure regulator, not a cheapo consumer model.

You don't need to worry about check valves, but make sure that there is a shutoff valve after each machine so that you can isolate either machine.

I'd also put one of the extra pressure vessels that you have near the blast cabinet. That will help keep the pressure steady when you are blasting.

Alternators are available for single phase machines, but start with staggering the pressure switch settings, if the pressure switches can be adjusted. You'll want at least 10 PSIG between the on-line of one machine and the off-line of the other. So, set one machine for 125-150 and the other machine to 115 to 150, as an example. You can try less then 10 PSIG, but with this class of machine the pressure switches are not the most accurate and you might cycle the machine too rapidly.