# Question about old Quincy compressor



## JDMark

I have a Quincy 310, 1950 vintage. I have it mostly rebuilt & about ready to try but am somewhat puzzled by the unloader circuit.

Any pictures or info I find on a 310 show the hydraulic unloader, actuated by oil pressure. On this system, there seems to be only 1 air line going from the hydraulic valve to the unloader tower.

On mine, I have centrifugal weights on the crankshaft that close the unloader valve after it is up to speed. Air is allowed to flow from the tank to the unloader when it is stopped, pushing down on the diaphragm & deactivating the valve. 

There is a tee on the unloader tower. The line on the other side goes to what I believe is a check valve. What I haven't figured out yet is how the unloader pressure gets bled off after the crankshaft valve closes. Or does this valve bleed the pressure off itself?

Is anybody familiar with this system?

Thanks,
Mark


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## JDMark

Ok....evidently not too much knowledge about these around anymore. I have the unloader tower rebuilt with a new diaphragm so I am about ready to hook up a 120V air valve from one leg of the 220 with a timer on it & just not use the flywheel weights.


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## Apple19

Interesting read. Thanks for the share.


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## KenB

Apple19, I'm new to this site and I selected the 192.168.1.1 to look at the information I thought it was about quincy air compressors. It turned out that IP is information on setting up a linksys router. What am I doing wrong? Thanks, KenB


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## KenB

Apple19, my apologies... I didn't look closely enough. KenB


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