Air compressor - Contractor Talk - Professional Construction and Remodeling Forum

Bill · 10-13-2007, 10:41 AM

Does anyone know where a site is that explains the way a gas compressor releif valve works, or maybe someone here does. I fixed my compressor, the head gasket had a split, so I replaced it, fired it up and it pumps good now. But now the releif valve seems to be popping on and off very quickly, sounds like a machine gun. I tried taking it apart, spray light lube on the ball underneath, put it back together, and the same thing. I even tried adjusting it up and down. From what I can tell it looks like there may not be enough presseure holding the valve up, I can take my finger and lightly set it on the pop off valve and it will stay open like it should, but as soon as I let it go, it starts popping real fast. I need to try to fix this thing for monday morning, so any help would be appreciated

randomkiller · 10-13-2007, 04:05 PM

Replace it the spring must be worn out

Dustball · 10-13-2007, 04:33 PM

Quote:

Originally Posted by abp

Does anyone know where a site is that explains the way a gas compressor releif valve works, or maybe someone here does. I fixed my compressor, the head gasket had a split, so I replaced it, fired it up and it pumps good now. But now the releif valve seems to be popping on and off very quickly, sounds like a machine gun. I tried taking it apart, spray light lube on the ball underneath, put it back together, and the same thing. I even tried adjusting it up and down. From what I can tell it looks like there may not be enough presseure holding the valve up, I can take my finger and lightly set it on the pop off valve and it will stay open like it should, but as soon as I let it go, it starts popping real fast. I need to try to fix this thing for monday morning, so any help would be appreciated

What pressure is this happening at? A pressure relief valve should be closed at normal operating pressures, not open. When the system exceeds the pressure relief valve's rated opening pressure, the valve opens to exhaust the air pressure down to a safe pressure.

Bill · 10-13-2007, 08:42 PM

It is doing it at all pressures. I tried to adjust it. From what I can see, the unloader valve assembly may be bad. I just found out the GC will have temp power on the job, so I can use my electric one. I will call and order the whole unloader assembly monday. Might as well replace it all at the same time.