Small line on Saylor Beall 705 pump

[jdclarey]

In setting up my compressor I bought used, I have a question. I have one small copper line which I know goes from the pump to the check valve which I believe to be pressure release. But on other compressors like the 80g Quincy, there is another small line that goes from the pump to the regulator switch. My regulator switch has the fitting for this, but the old owner never had a line running to it. Can I assume I don't need that line on this pump?

 

[Ing3018]

In basic form, the 705 just has a small line that runs from the check valve at the tank over to the unloader valve on front end of the pump. These pumps are not typically unloaded at the pressure switch. You can use a really basic pressure switch with just a single port, assuming you are handling the motor electrical through a magnetic starter.
Other lines, if any, on these might be for a pneumatic tank drain or continuous run feature.

 

[The Tool Tyrant]

Ing3018 is spot on...SB pumps utilize a centrifugal unloader.