Air compressor unloader hookup?

[oneBADDz]

I've done some research but can't find exactly what I need to know. The guy rebuilding my old Worthington compressor has disappeared with it, so I bought this monster 4cyl to replace it. There is a copper line that connects all 4 cylinder to the center T. Each big head has a port. Then there's a T on what I'd call the crankcase down low. I'm not sure if the unloader is all I need to think about here or what do do with all of these connections. It almost seems like it may have been set up as a constant run gas powered compressor, I'll be running it electric with a pressure switch to turn it on and off.

Air in and out is easy, but what about the rest of these ports?

 

[Jswain]

https://eatoncompressor.com/wp-content/uploads/7-5-HP-Single-Phase-80-Gallon-Air-Compressor.jpg

There's a pic of how to plumb. The two connected together currently would go to a valve you could open to let the compressor staying running during high use(sandblasting). It unloads the pressure and the pump/motor keep spinning.

The two with the elbows on the heads would go, as you assumed, to the T on the front of the crankcase & would be connected to the centrifugal unloader.

If you don't want continuous run you could cap the two that are currently connected and just hook up the other two elbows on top of the heads to the T on the front of the crankcase to function like normal.

 

[larry4406]

My electric motor driven Puma compressor has unloaders and a valve that I can flip to enable start/stop operation or continuous run.