Air compressor question
09-14-2010, 03:04 PM
#1
Race Director
Thread Starter
Air compressor question
My old one died so I got a HF 8gal 2hp 125psi new one.
It works fine, but when I am done, it does not hold tank pressure - after an overnight sit - power off - it'll bleed down to about 20-30 psi.
I checked all the external fittings with soapy water & found one leak & fixed it.
Still bleeds down overnight.
The question is this. Do these inexpensive compressors bleed pressure backwards past the compressor piston rings? If yes I guess there is nothing wrong with it.
There would need to be some one way valve somewhere to prevent this, but I don't have a lot of knowledge on how these are usually built.
Maybe as it breaks in it'll hold pressure better.
Thanks.
It works fine, but when I am done, it does not hold tank pressure - after an overnight sit - power off - it'll bleed down to about 20-30 psi.
I checked all the external fittings with soapy water & found one leak & fixed it.
Still bleeds down overnight.
The question is this. Do these inexpensive compressors bleed pressure backwards past the compressor piston rings? If yes I guess there is nothing wrong with it.
There would need to be some one way valve somewhere to prevent this, but I don't have a lot of knowledge on how these are usually built.
Maybe as it breaks in it'll hold pressure better.
Thanks.
Last edited by froggy47; 09-14-2010 at 03:07 PM.
09-14-2010, 10:40 PM
#2
Safety Car
I've got a Porter cable twin tank 4hp and it does the same thing (5 years now) my other compressor has a check valve between the compressor and the tank. It doesn't leak down so maybe they all would do it.
09-14-2010, 10:56 PM
#3
I bleed it intentionally by leaving the drain cracked open (on a 60 gallon monster) at all times...then I never forget to drain it. I see no reason to leave everything under pressure while I am not using it...could just be me.
09-14-2010, 11:05 PM
#4
Race Director
I've never had a compressor leak down that quickly. To me, the whole point of having a nice permanent compressor is instant air, any time.
While I like the idea of having the petcock leak down to prevent moisture build-up, you are also running it much more, therefor creating more vapor to begin with.
Shouldn't be an issue over the realistic lifespan, but compressing/decompressing also leads to fatigue.
Just some thoughts....if you don't mind waiting for it to build pressure, probably not worth installing any fancy valves or anything. However, I would think the manual would address leak down issues, and I'd return a compressor that could not hold air overnight.
While I like the idea of having the petcock leak down to prevent moisture build-up, you are also running it much more, therefor creating more vapor to begin with.
Shouldn't be an issue over the realistic lifespan, but compressing/decompressing also leads to fatigue.
Just some thoughts....if you don't mind waiting for it to build pressure, probably not worth installing any fancy valves or anything. However, I would think the manual would address leak down issues, and I'd return a compressor that could not hold air overnight.
09-14-2010, 11:53 PM
#5
Race Director
Thread Starter
Thanks guys,
It's not worth adding any special valves to prevent leak down, it's just a $100 comp.
I did get used to the old one being ready to go, sort of like having my computer booted up and ready to go in the morning.
I'm pretty good about draining off the h2o once a week(end).
I did hack the shutoff to get a few more psi (just 130) and it is sweet to have the extra to hammer off tough nuts.
It's not worth adding any special valves to prevent leak down, it's just a $100 comp.
I did get used to the old one being ready to go, sort of like having my computer booted up and ready to go in the morning.
I'm pretty good about draining off the h2o once a week(end).
I did hack the shutoff to get a few more psi (just 130) and it is sweet to have the extra to hammer off tough nuts.