JUN-AIR 6X25 compressor

by Joe

Jun Air 6/25 air compressor

Jun Air 6/25 air compressor

I have a JUN-AIR 6X25 compressor working for dental surgery.

It works normally but as the pressure builds up,the unloader valve, which is under the pressure switch, keeps falling out after hearing the "hissing" sound and the compressor shuts off.
Joe.
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Well Joe, it seems to me that your Jun Air 6-25 air compressor is not working normally, given the symptoms you describe.

I am not quite sure what you mean by "unloader valve, which is under the pressure switch, keeps falling out"? You mean the switch itself is detaching from the compressor, or that air is leaking out of the unloader valve?

If the latter, please see the pages about compressor Check Valve operation on this site, what they are, what they do, and the symptoms of one that has failed.

Again, sorry, I'm not quite sure about this either ... "after hearing the "hissing" sound and the compressor shuts off"? Is the compressor shutting off when the tank pressure has reached the normal cut out pressure setting for your JunAir 6x25, or is the compressor shutting down before that pressure level is reached?

Please respond as a comment here.

Cheers,

Bill



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Jan 22, 2013
Re: JUN-AIR 6-25 COMPRESSOR
by: Joe

Sorry that some of the info did nor comr over clearly. Here we go again!
when the tank pressure has reached the normal cut out pressure setting,there is the hissing sound and the UNLOADER valve is dislodged from its connection with the pressure switch.
The air continues to leak through the unloader valve until tank is empty(gauge falls to 0.
Thanks again.
Joe
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Joe, the unloader valve is supposed to open when the compressor reaches cut out. That it continues to bleed air after the trapped air over the piston is vented tells me you have a problem with your tank check valve leaking.

Bill

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Jun-Air 12/25 - Oil and Water in Air Receiver Tank

by Gustav
(Copenhagen, DK)

Hej Bill

A friend has just lent me a Jun-Air unit that was apparently neglected for a good number of years. The 12-25 model unit was incredibly heavy. It had to be carried on a trolly cart. I washed it down and check the lines and seals. All seemed to be fine. But while I manipulated the unit, I could faintly hear some light splashing sounds in the unit. Because it is oil filled, I assumed it was this. I started the unit, and all seemed sound. However, and this is the punch-line, I tried to open the purge valve and oil and water started to spit out. Because this valve is placed on the top of the tank, it made it difficult to properly purge the unit. I tapped off a litre, but I had to give up because I didn't have any containers big enough to collect all the water and oil: The whole 25 L tank was filled up!

The unit started its life in the food industry, apparently to drive a cold-cut or meat-slicing machine and the was almost constantly powered up. While my knowledge of compressors is limited, I have never seen this type of problem before.

The Purge valve is a litte odd, though, and feels gummi when turning it. Is it defected or is it an auto-purge valve? Can this unit be used, or does this symptom of water and oil in the air tank indicate that it has served its life?
Could the unit be refurbished if so?

Cheers,

Gustav
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Gustav, thanks for the tip on the broken link.

I think that Jun-Air puts the tank purge / drain valve on the top, with an inside line to the bottom of the tank, for their users convenience. Most tank drains are on the bottom since gravity and air pressure blow the water and crud out easier there.

The oil and water in the tank is not unusual, as teh 12/25 is an oil lubed unit, and over time, the piston seals wear, and lube oil wicks into the air going into the tank. Lots of oil would indicate that the seals are well worn and need replacing.

As to the tank, drain it. All of it. Get it empty.

If you cannot run the compressor to get air into the tank to force the water out, that is a problem, and would probably mean removing the tank to drain it properly.

Is it worth fixing? They are quite an expensive compressor when new, yet clearly with that expense you get long life and a very quiet compressor. You'll have to get parts pricing from a Jun-Air distributor to determine if rebuilding it is worthwhile. I cannot tell you that.

If it is saveable, and it were mine, I sure would.

Cheers,

Bill


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