Air filter/regulator: This might be a dumb question but...

[monteperformance]

I just installed this Speedaire filter/regulator that I had acquired used a while back. It is constantly hissing air and then I found this hole (about 1/8" diameter) in the part that covers the regulator spring. Should that be there? That is where the air is leaking from. I'm guessing no but I really don't know much about these.

 

[TwoInch]

is it designed to relieve back pressure to atmosphere? i am unfamiliar with those type of mechanisms, but many are designed so that when you lower the pressure with the regulator, it will relieve the pressure downstream from that point, so that the line will be at the regulator pressure. it does this by venting it to the atmosphere at the reg itself. i would assume that is what that hole is for.

have you tried turning the reg all the way to max PSI and see if it stops? are you sure it is not plumbed in backward? i would imagine if it was plumbed backward, it would constantly vent the high pressure. there should be arrows pointing the direction the flow should be.

 

[monteperformance]

In my experience with other regulators, they vent pressure while you are lowering the set pressure but then they stop. This one keeps venting pressure constantly. There are no arrows for flow, but there is a sticker that specifies max inlet psi on the left, which is where I have the inlet air coming in. I think it keeps venting weather it is set to max, min or anywhere in between, but I'll check it again later.

 

[TwoInch]

right, thats what i was trying to communicate. while lowering the pressure they will vent the pressure down to your selected PSI. so if you have it plumbed backward, it would constantly try to vent the high pressure.

i would start by turning the regulator all the way max open, and see if it stops hissing. then try max closed(off). can also try and shut compressor off at 50psi or so, and turn the reg up to 100psi, and see if it is still hissing. if so, its defective, or backward.

report back with what you find. im curious.

 

[larry_g]

It is entirely possible that the regulator needs a rebuild. Within the regulator are a couple of o-rings and a diaphragm that can leak. If you have the P/N of the regulator go to the Grainger site or call them and see if a kit is available for it. They do not have an infinate life.

What others have been talking about are relieving or non-relieving regulators. A relieving regulator has a vent within the adjustment area that will vent down stream pressure some increment above the setpoint. Google relieving regulator.

lg
no neat sig line

 

[monteperformance]

I put it back together last night and it seemed to be working fine. I went back and checked it after a few hours and it was holding good. Then I checked it this morning and the entire tank had drained, so something is still not right. I checked the Grainger site and its a discontinued item, and I don't see any rebuild parts for it, so I guess I will start looking for a new one. Thanks for the info.

 

[TwoInch]

maybe contact grainger, they may replace it with a different model.