Sullair Iso 9001 Air Compressor Manual

[Victoria Steigerwald]

Thesafety valve is just a rubber disc held closed against the seat by a spring. If there was dirt caught in the the valve or the rubber was damaged you would get a leak. If you press or pull on the valve you'll run some air through it, this might clear the valve and allow it to seat properly. If it continues to leak, it is defective and should be replaced.

The pressure drop overnight was probably caused at least in part by the very hot tank cooling off so there may not be a problem with the valve. Another possible cause for an air leak is air escaping back through the compressor. If the leak is minor, I would leave alone for a week or two to see if it clears up as parts seat better.

JohnW, thanks for the remedial physics lesson. Didn't consider the higher pressure caused by hotter air. I don't normally plan on running the compressor for 1+ hour non-stop. In fact it's rated at 80/20 duty cycle, so it's supposed to have a break. The tank was still pretty warm when I shut the power off for the night. I'll try pulling the ring a couple times and letting some air blast out the valve. It doesn't leak around the threads (tested with soapy water). However, I can see the rubber disc you refer to just start to peek out of the holes on the valve (psssssss). If I push the plunger in by hand, it stops the leaking. This should be a pretty cheap part to replace if it's defective, so no big worries just a bummer on a brand new piece of equipment. It appears to have a threaded end that I might try tightening up a bit to give the spring a bit more tension.

If this brand-new compressor is leaking, it should be covered by he warranty. The pressure will drop if the tank and air are hot and allowed to cool, but while it's being used, it's just working pressure.

"I cut this piece four times and it's still too short."

I would agree with another poster that you are pushing the compressor hard by running at the maximum pressure, it's like red lining a car's engine, you can do it but it doesn't improve the engines life span.

I would run the unit at as low a pressure as possible that gives you the operating pressure you need for the tools you are using. With a sixty gallon tank you should still have adequate storage volume for most air consuming jobs at a lower pressure. Start out with a lower setting and only raise the cut out pressure if experience proves that you need it. If you really need to run at the maximum pressure your system is undersized.

The leakage past the safety may be caused by your getting close to the release pressure especially if the safety is set a bit light and the compressor cut off switch is cutting out a little bit higher than it is set for. None of the pressure registering components of a typical compressor are all that accurate, I would assume that any of them could be off by 10 pounds or so plus or minus.

Thanks again for the suggestions. Most of the stuff I use compressed air for does not need to be at 135 psi. I use the blow gun more than anything, followed by the HVLP sprayer only occasionally. I'll see if I can turn down the cut-off switch down to 115 or so. I'd also like to turn the cut-on pressure down to about 80 psi. Hopefully the manual explains how to do this. This compressor is definitely overkill for my needs, but I just fried a 21 gallon HF compressor, so I wanted to buy the last compressor I'll need for 30 years.

The adjustment you are contemplating "tightening up" is the means by which the valve manufactrurer sets the actual relief pressure. You can quickly change your 150# safety relief valve into a 200# or 250# or 300# relief valve .... more or less rendering it useless. Often one only has to unseat these valves one time, and they refuse to seal back. Poor quality. I'd approach your dealer for a new one under warranty, or simply buy a new, higher quality one and be done with it.

For starters, it should not take 20 minutes to fill 60 gallon tank.The tank should not get hot, warm maybe.As far as the safety valve leaking, a new one should not leak that much air overnight.Many compressors will leak a small amount of air over a days time, not a problem . Your compressor is leaking too much air and the fill time is way excessive.I would guess that 5 or 6 minutes to fill 60 gallons would be more like it,except for the first time from dead empty. Then maybe 8 minutes.

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