air compressor gurus - quincy 210 questions

[87jeepwrangler]

At this time, I do not need my Quincy 210 pump to operate in a continuous run mode (even though it has unloaders at the top). It will strictly be used in conjuction with a pressure switch to turn the motor on and off. I have a combination check valve/unloader that I intended to use, if it will work for my needs.

Here are pictures of the parts in question…







these are the check valve and combo check valve/unloader



My plan was to run a copper line from the 210 head, into the check valve/unloader, then into the pressure vessel. I was then going to simply plug the lower port on the bottom fitting on the side of the crankcase. Will that work? Is it that simple?

 

[MacMcMacmac]

Even simpler would be to run a sense line from the tank through the unloader valve on the crankcase on to the unloader towers and plumb the compressor discharge line directly into the tank without a check valve at all. Quincy did this for years.

When the pump comes up to speed and oil pressure builds, it cuts air to the unloader towers allowing the intake valves to operate freely. When the compressor cuts out, the pump stops spinning, the oil pressure goes to zero, and air from the tank is allowed into the unloaders, depressing the intake valves, blowing down both cylinders. The exhaust valves then act as the check valve in the system. This will also allow you to diagnose bad discharge valves quite easily by hearing.

Incorporating the hydraulic unloader valve gives you the protection of keeping the compressor unloaded if the oil pressure is not building.

You can still install the check valve in the tank if you like. There is the added benefit of not having to blow down the entire tank if you need to do any work on the compressor.

 

[My Old Tools]

That sounds like how mine is working, but to be honest, I haven't spent a lot of time thinking about the plumbing since it works. It is plumbed direct to the tank and I was thinking I needed to add a check valve. Now I'm thinking not. I'll have to look and see where the sense line for the pressure switch is plumbed.

 

[Trey T]

Agreed w/ macmacmac!!!

I run mine w/o a check valve (advantage of having disc valves pump head). Essentially, both lines (for unloader and pump discharge lines) are connected to the same spot of the tank.

 

[87jeepwrangler]

ok, so skip the "plug" and the check/unloader. then just plumb both the unloader line and pump discharge to a Tee, directly at the tank.

 

[Trey T]

Since you already have the check valvce, just use it on your tank as another layer of leak prevention. I'll try to take some pics of mine and post it.

If you need parts for your 210, let me know, I got several 210 pumps I can part out.

 

[87jeepwrangler]

Awesome. Thanks.

I like the idea of using the check/unloader anyway since I already have it. And since I am, what is the benefit of of running an additional "sense line" instead of just capping it? It adds additional tee's, fittings, and lines. Just to help with future bad discharge valve diagnosing?

 

[Trey T]

Pictures attached. My 210 is a higher ROC (newer) which uses the cheaper hydraulic unloader valve but essentially, they're the same; one line to the head (Diaphram)and one line to the tank (Receiver).

Just cap it because it will be redundant and you'll have to spend more money on brass fitting and lines.