can 2 air compressors be joined to boost CFM? they are not identical. I am not concerned about PSI, just CFM. if yes, how best to do it? "T" the output lines together, or have them both pump into a separate tank?
Connect the two tanks, separately from the output line. You would probably need to use the pressure switch from one compressor, to turn both on and off, so they come on and off together, otherwise one may sit there and do nothing. Unless you can adjust when they come on and off individually to come on and off at the same pressure.
What range of CFM do you need? Run the outputs to a manifold, then into a larger tank. You'll probably need bigger ID airlines & regulator connected to your output application to take advantage of the bigger tank.
just make up a T connection and hook them together, they don't have to be the same size and type. i use quick connects. if you're using a lot of cfm, both will run continuously. they will start and stop independently on their own pressure switches.
That's how we're set up at work. Four compressors, two in one building and two in the other, but all tied into a common distribution network. At night, one compressor runs the whole place. During the day, all four might run. They each sense local pressure and cycle accordingly. There are a couple of large accumulators in the system, one near each compressor pair, to keep the compressors from cycling repeatedly.
this is what I'd like to do. while I value and appreciate the other responses, they involve more work (cost?) than just selling the 2 and consolidating to a bigger one. I only need about 7 cfm, and have two compressors that do about 5.5 each. if I T them together, do I need any check valves, or is that handled by the compressors themselves?
Look at the duty cycles on the compressors. If one is 100% - that one should be set to come on sooner ie. higher set point on the pressure switch. If neither are 100% duty cycle the trick is to make sure that both of them shut off regularly during use so they can cool down. I wouldn't worry about check valves - most compressors have some form of check valve between the compressor head and tank anyway so they can "unload" the start up forces on the compressor head. What I would do is connect an unregulated line from one compressor into the other, and then draw regulated air off the larger tank.
This. One of the systems I operate has one 150 hp, one 200 hp and a dinky little 55 hp compressor manifolded together. We run a total loss system rated at 775 scfm at 95+ psi. They cycle on and off as they need to, independently. We don't use quick connects though except at a couple of scab points. Everything starts off at a 6" manifold and necks down over the course of the run.
