air compressor, tank pressure

[RalphWD45]

I bought a Rogers, commercial grade, skid mounted, air compressor, at a consignment auction. It was originally hard wired, but I put a 240 pigtail, on it to try it out at home. It has a Quincy model 325 18 2 stage compressor on it, and is shutting off at 145 lbs, tank pressure. None of my smaller compressors, go that high on tank pressure, and I am wondering about adjusting the pressure switch, down to 120 lbs, for safety? Is this needed? I also found an air leak on the unloader valve tower, and have ordered a new diaphragm, for it. I hope that seals the valve. Do you recon, that excessive air pressure, might have caused the unloader valve to leak?, I still hear the unloader valve unloading, when the unit shuts down, so I guess it is still working.

 

[glennster]

i dont think your pressure is too high. my shop compressors run at 175 psi.

 

[Janicholson]

I agree with Glennster, for your own piece of mind, the tank will have a max working pressure tag on it, find that and be happy. Jim

 

[Russ from MN]

What is the safe working pressure on the tank? I wouldn't exceed that. Some people crank up their pressure setting to get more power out of impact wrenches. If you have good quality air tools you should get by just fine with it set 100-120, that's where I have mine.

 

[Bob Bancroft]

2 stage compressors typically run at higher pressures, like what Glennster has.

 

[circus]

If the tank came with the compressor chances are it'll be safe at the higher pressure. Mine has a magnetic motor controller that handles the higher current. This allowed for two, low current, pressure switches. I have a choice between 120psi for economy or 180psi for power with a flick of a 2-way switch.

 

[504]

I agree, mine is factory set at 175 psi. There may be a pull ring(looks like a key chain ring)on the relief valve it should pull kinda hard but air should come out. There will be a psi number on the valve, small but it will be there. If it says 200 you know you are ok, if it says 150 then the valve is not working and something is wrong.

 

[Steve@Advance]

The compressor is probably good for it, but do you need that much pressure?

Keeping it down to 120 or so is a safer pressure, less likely to blow lines, hoses, someone get hurt with a blow gun.

Kinda your need, your choice.

 

[Stephen Newell]

It may be a little safer to lower the pressure but I would probably leave it alone. I had a compressor that stopped at 175 psi but I just regulated the pressure down to 120 to run through plumbing in the shop.

 

[Mule Meat]

As others stated. You should be okay.
My shop compressor tops out at 175. I have four outlets regulated to 125 psi and three that have a full 175 psi.

The 125 is good for all around work. The 175 with larger hoses is handy when using 3/4 and 1" impact wrenches.

 

[TimV]

I also have a Quincy 325. Mine's set at 175, and was when I got it a number of years ago. That's a pretty standard pressure for them and 145 is certainly not enough to worry about it causing your unloader leak. As mentioned, if your tank will hold it, the compressor will.

 

[Steve A W]

The number one enemy of an air compressor is heat.
At 120 psi the compressor will run cooler and last longer.
All the air tools I've ever bought say to regulate air
pressure to 90 to 100 psi.

 

[Hobo,NC]

Yes but you want be very productive at 90 psi... About the only thing I regulate is a nail gun other than that it gets fed 175/180...

To be on the safe side I would replace the pop off valve are test it regularly.

 

[Pete in Holland MI]

Not knowing how well the tank was kept drained during its life time, it's probably a good thing to reduce the shut off pressure some.

 

[Handsome Devil]

(quoted from post at 13:37:10 08/13/20) I bought a Rogers, commercial grade, skid mounted, air compressor, at a consignment auction. It was originally hard wired, but I put a 240 pigtail, on it to try it out at home. It has a Quincy model 325 18 2 stage compressor on it, and is shutting off at 145 lbs, tank pressure. None of my smaller compressors, go that high on tank pressure, and I am wondering about adjusting the pressure switch, down to 120 lbs, for safety? Is this needed? I also found an air leak on the unloader valve tower, and have ordered a new diaphragm, for it. I hope that seals the valve. Do you recon, that excessive air pressure, might have caused the unloader valve to leak?, I still hear the unloader valve unloading, when the unit shuts down, so I guess it is still working.

I can think of no reason for the air pressure to be set that high? My 1940 Champion 5 hp is set to kick in at 90 and stop at 120 I think. My Gardner Denver towable screw compressor has air pressure at 100 lbs if not mistaken. Most air tools as mentioned are designed to work somewhere in the area of 90-100 lbs pressure. If this compressor has been running at this pressure forever it is probably safe. When I rebuilt my old Champion I don't recall but I know I replaced the two safety valves down to 120 lbs I think and reset the starter/pressure solenoid or what ever it is called to where it is today. My old Champion has its limitations but has 80 gallon tank. The volume helps, but for serious work it is a little under powered. I don't think increasing the pressure would make that much difference in my case. Your Quincy is a great pump and probably runs circles around mine. To me the question is do you need that high pressure and are you gaining anything from the higher pressure? On the other hand if it isn't broke do you need to fix it? I just don't see the need in most cases. If your going to replace the pressure valve and safeties anyway? Your choice. Don't think it a serious right or wrong choice. Regards, John.

 

[45cole]

(quoted from post at 19:16:00 08/13/20) The number one enemy of an air compressor is heat.
At 120 psi the compressor will run cooler and last longer.
All the air tools I've ever bought say to regulate air
pressure to 90 to 100 psi.

Like Steve says, most air tools will call for less than 90 psi, with a lot working well in the 60-80psi range so I don't see why compressors compress so high. A two stage will take the pressure to the 150#ish level, I keep my singles at 125psi. It's best to take down and clean the unit before use, many times the diaphrams or reed valves are dirty. A head unloader problem is very common, the problem is the check valve from the pump to the tank, usually mounted on the tank. Take it off and clean it, works for me 50% of the time.

 

[Bspauld]

my compressor shuts off at 125 PSI, my neighbors shuts off at 170 PSI, my impact wrench has a lot more power at his PSI then mine, Its a lot of difference.

 

[45cole]

(quoted from post at 09:20:34 08/14/20) my compressor shuts off at 125 PSI, my neighbors shuts off at 170 PSI, my impact wrench has a lot more power at his PSI then mine, Its a lot of difference.

You'll have to watch it - I've opened up a lot of impact wrenches that have broken hammer frames and dented anvils from overpressure. The IR's say no more than 90psi on the all metal units, not sure on the poly stuff.

 

[Hobo,NC]

I can get 10 years are more out of a IR composite @180 pis working it every day... Anyone that has good air that works a impact, air ratchet will tell y'all the performance goes south below 145 psi...

If you have it use it life will be good...