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Topic Review (Newest First)
02-23-2011 08:15 PM
930dreamer
Quote:
Originally Posted by Silverback
That brass fitting in the top of the tank is a check valve, so air can only go into the tank, and the small line is an unloader that connects between the pump and the check valve so it doesn't have to start against the tank pressure. I'm actually surprised that it's necessary, I would expect that the volume between the pump and the check valve is small enough and the pump would leak enough that after a few seconds there wouldn't be significant pressure there...

Along these lines, I've always wondered if there is any way to tell which way the compressor should turn without a pulley on it? I have a big old Kelogg compressor head that I intend to setup at some point but I have no idea what direction it needs to turn.
What model Kellogg?
02-23-2011 06:16 PM
weirdbeard
Quote:
Originally Posted by ogre
that is one heck of a compressor. your lucky to have 3 phase in your shop.
with all the shops around here going under, used 3 phase stuff is cheap now.

that tube may be an clutch type unloader.
some of those bigger units were set up to run the motor continuous
and clutch the compressor in and out.
this avoids a lot of restarts of the motor under high air use.

our shop has a 7 hp 2 stage that puts out 34 cfm @ 90 psi.
we can set it to run all the time by opening the intake valves using a regulator.
never have, we don't use that much air.
it looks like your compressor has 4 pistons; twin 2 stage compressor heads.
might be 50 cfm @ 90 psi. that's a whopper.
Your are right. The three phase stuff is going super cheap right now.

That is very interesting about running the motor all the time.. Just like a gas compressor.. I never thought about that. We really don't use that much air, but thats good to know.
02-23-2011 09:55 AM
ogre that is one heck of a compressor. your lucky to have 3 phase in your shop.
with all the shops around here going under, used 3 phase stuff is cheap now.

that tube may be an clutch type unloader.
some of those bigger units were set up to run the motor continuous
and clutch the compressor in and out.
this avoids a lot of restarts of the motor under high air use.

our shop has a 7 hp 2 stage that puts out 34 cfm @ 90 psi.
we can set it to run all the time by opening the intake valves using a regulator.
never have, we don't use that much air.

it looks like your compressor has 4 pistons; twin 2 stage compressor heads.
might be 50 cfm @ 90 psi. that's a whopper.
02-22-2011 09:09 PM
oldred
Quote:
Originally Posted by Silverback
I have a big old Kelogg compressor head that I intend to setup at some point but I have no idea what direction it needs to turn.

If it has an oil pump, or even by looking at the slinger if that type, or if it has a centrifugal unloader control you can determine direction by looking at those parts and you would know for sure.
02-22-2011 08:43 PM
Silverback That brass fitting in the top of the tank is a check valve, so air can only go into the tank, and the small line is an unloader that connects between the pump and the check valve so it doesn't have to start against the tank pressure. I'm actually surprised that it's necessary, I would expect that the volume between the pump and the check valve is small enough and the pump would leak enough that after a few seconds there wouldn't be significant pressure there...

Along these lines, I've always wondered if there is any way to tell which way the compressor should turn without a pulley on it? I have a big old Kelogg compressor head that I intend to setup at some point but I have no idea what direction it needs to turn.
02-17-2011 06:33 PM
weirdbeard WOO HOO! Thanks oldred! I'm gonna change the oil and put her to work.
02-17-2011 06:06 PM
oldred Ok, false alarm. I see it now and it is just fine there, in fact that is what I meant when I said it should be plugged into the pump-to-tank circuit. Somehow I got the false impression from those first pics that the line was simply plumbed into the tank by itself and the braided discharge line went to another fitting, going back and looking at the first pics I can't see now where I got such an idea-sorry about that!

Looks like that thing is going to be a real beast, you did well!
02-17-2011 05:45 PM
weirdbeard Lets see if these are any better.. I am a bad photo taker person..







I don't see anything plugged off.. Not sure where else it could have gone.
Thanks oldred.
02-17-2011 05:21 PM
oldred If you only ran it less than a minute then you can forget about it even happening., I can guarantee it didn't hurt anything. As for that line you need to examine the pump head and see if there is anything that has been plugged off, it might explain where that line goes. More likely it was plumbed into the discharge circuit somewhere between the back-flow valve in the tank and the pump. Can you get a better picture of that line/tank connection? I know you have a clear close up but the fitting is partially obscured at the top by that braided line.
02-17-2011 04:43 PM
weirdbeard Thanks a lot Oldred. I was hoping you would chime in. I did only run it for about 30 seconds backwards and it seems fine now.. I was a little worried.

That little air line is going into that brass fitting.. I guess it could be a one way valve.. I am going to check that out.. That little line is thing only thing that looks kind of molested on the compressor..

I have never heard of the brand and I cannot find any info on it.. Its made in Rochester NY and seems to be well built.. I wanted a Quincy, but this one was a steal of a deal I think.
02-17-2011 04:35 PM
oldred I think what you will find under that cone shaped cover is a centrifugal unloader control. I am not totally familiar with that particular compressor but it seems to be a normal set-up and as such it would appear that line is plumbed in wrong, the unloader should relieve head pressure instead of disengaging the pump. Is that line directed into the tank or is that fitting on the tank directing the circuit to the pump, is the fitting a one-way valve? You can use compressor oil or 30wt non-detergent oil, whether having the rotation direction wrong would cause a serious problem (except for cooling) would depend on whether or not the pump uses an oil pump or slinger type oiling. Obviously if it has a pump then it would not lube if turned backwards however if that is the case and it ran only a short time then probably little or no damage was done. Those things tend to "splatter" lube a little even if the pump is not working and running one backward a few minutes usually won't hurt anything, not saying it is OK to run one backwards but if it happens accidentally for a short time it usuall is no problem.
02-17-2011 04:14 PM
weirdbeard Ok.. It was spinning the wrong direction.. It was working, but it sounds better now.. It does not seem to have hurt anything.. I was looking for an arrow on the pulley, but nothing.. Seems like they would have done that..

I have a guy telling me that the little air line going to that crank cover is disengaging the compressor mechanically until the motor gets up to speed.. I might just open it and see what the deal is for myself..

So do you just run normal compressor oil in these big ones? Or could I use some type of motor oil?

Sure could have used a owners manual with this one.
02-17-2011 05:49 AM
cal1320 Pulley on compressor should blow air towards the compressor jugs to provide cooling. To reverse rotation on 3 phase you need to swap any 2 of the 3 hot leads that feed the motor. This can be done at the disconnect or breaker box. Please make sure you have turned off the power and check for voltage with a tester before you work on electricity.
02-17-2011 03:59 AM
930dreamer
pump

There should be an arrow on the pump pulley that shows rotation.
02-16-2011 09:40 PM
NEW INTERIORS
Quote:
Originally Posted by BOBCRMAN@aol.com

The odd looking tube has a valve in the compressor end that equalizes the head pressure when pump stops. This keeps the pump from trying to start against full tank pressure.
Yes... your right about the little line bleeding off the head pressure, But they are not usually tied in at the crank case..
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