* Regulator leaks and/or shows higher pressure than on the supply side

by Keith
(Ham Lake, Mn)

I have a 25 gallon Craftsman professional model upright compressor.


I was blowing out my sprinklers the other day when the regulator began to leak. It would only stop if I turned it in much further and increased the pressure setting way too high. Also, the regulator gauge now shows a slightly higher pressure than the tank side gauge.

I bought a new regulator and this one seems to do much the same thing. It leaks or vents unless I crank it in to very high pressure and the gauge will not ever go below what the tank pressure gauge shows. Also it will not release air to the hose at high pressure settings.

I have not replaced either gauge. Though both seem to work fine, the tank side always shows slightly less pressure than the regulator gauge.

Do you have any idea what's going on?

Thanks a lot.

Keith

Comments for * Regulator leaks and/or shows higher pressure than on the supply side

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Nov 07, 2018
Water issue - for Keith
by: Bill

I actually didn't suggest that you push water upstream, but meant that if, for some reason, there was sufficient water in the line that you were blowing out, and it overcame the air pressure, it would slightly (or a lot, maybe) compress the air downstream of the regulator to a higher pressure than the regulator setting, thereby setting off venting.

Water in the regulator wouldn't help.

Nov 07, 2018
Water Issue?
by: Keith

Bill,

Thinking about this more. You suggested pushing some water upstream. I'm not exactly sure how that would work but I'm wondering - Since I was blowing out sprinklers, is it possible that I got some water in there and that caused the problems? Not that important if you're busy. Thanks again.

Keith

Nov 07, 2018
Two Bad Regulators
by: Keith

Hi Bill,

Sorry it took so long but I finally got back to this. Long story short, I couldn't figure this thing out and ended up trying another regulator. This one being an OEM one from Craftsman. It seems to work fine now. I don't know why the first replacement didn't work as they appear to work the same way and are pretty similar. Thanks for our help. Nice job on this web site.

Keith

Oct 11, 2018
Reglator leaks
by: Bill

Keith, the regulators you speak of are relieving regulators, meaning that they are supposed to vent air, in other words leak, when the downstream air pressure is higher than the setting on the regulator.

If your regulator is venting it's because there is pressure buildup in the downstream air that's higher than the setting. By turning up the regulator setting thus increasing the pressure through the regulator, the supply pressure became higher, and the regulator stopped venting downstream air.

Why is it venting? Pushing a column of water upstream, thereby increasing the load, and then that water flowing backwards a bit to actually compress the air in the line might do it.

As to this "the tank side always shows slightly less pressure than the regulator gauge" that is weird. Regulators work by reducing pressure, and if the downstream pressure, displayed by the gauge on the regulator, is higher than the tank side pressure, that makes me suspect the gauges.

You say you bought a new regulator? Replace the gauge with the new one and let us know what you see, K?

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