Firefyter-emt
Member
In my last post a few of your mentioned that you relief valve did not properly work. Today I took a drive to the hardware store in my Jeep (topless in the rain to boot!) and I picked up the last needed fitting so I could test out my tank. Much like others, my tank was set to blow at 35psi. I removed the relief valve to see if it was adjustable and mine was. I took some photos to show you how to adjust the valve properly.
However, before I go there, I want to address the issue of tank pressure, regulators, and the roll they play.
On my tank I have eliminated the regulator and the extra valves. I was able to do this with a new gauge that will read vacuum or pressure. I am running ¼†NPT plumbing and valve on my tank so the flow rate of a ½†valve combined with a larger hose my indeed show different results. I have a larger compressor than most would have themselves. Mine is a full sized shop compressor designed to run a body shop. On my tank, the valve was very easy to control the flow rate into the tank at full line pressure (140psi) once the tank reached 55psi the relief valve will open and the tank will gain no more than 5psi with the valve left wide open. This shows me that a set up with a properly adjusted and working relief valve can not be damaged without the regulator. I would suggest that you test this every now and then by running the gauge over the set psi to blow off the valve to make sure it’s working properly.
Now my tank is rated to be used at 80psi and the government required test psi on the tank would be much higher so there is little worry at this time.
Ok, back to the topic.
First, let's see just what we have behind that valve!
Remove the valve by loosening that lock nut against the fitting and unscrew the entire thing. You will be left with parts that look like this:
With the parts laid out, they look like this:
The plunger seats against the inside of the fitting here:
With this valve you CAN NOT remove the housing and replace it with a new brass "T" fitting because the relief valve is part of the fitting that comes with the tank.
The psi is set by how much preasure it takes to push this spring away and allow the air to leak out. You might be able to replace the spring if you are not able to achieve the psi you want, but I would highly recomend you replace the relief valve and the fitting with a better one instead.
Here is the valve ready to ba adjusted. All that is needed is to hand screw the "cap" into the fitting and lock it in place with the lock nut. On mine, to achieve 55psi, I had to insert the cap all the way in and lock it there.
Here is what mine looked like adjusted to blow off at 55psi, note how far it is inserted into the housing. This is indeed how these are adjusted, so don't feel that this is a "hacked fix", but the proper set up for a relief valve.
I hope this helps some others to set up their tank beter. Feel free to ask if you have any questions!!
However, before I go there, I want to address the issue of tank pressure, regulators, and the roll they play.
On my tank I have eliminated the regulator and the extra valves. I was able to do this with a new gauge that will read vacuum or pressure. I am running ¼†NPT plumbing and valve on my tank so the flow rate of a ½†valve combined with a larger hose my indeed show different results. I have a larger compressor than most would have themselves. Mine is a full sized shop compressor designed to run a body shop. On my tank, the valve was very easy to control the flow rate into the tank at full line pressure (140psi) once the tank reached 55psi the relief valve will open and the tank will gain no more than 5psi with the valve left wide open. This shows me that a set up with a properly adjusted and working relief valve can not be damaged without the regulator. I would suggest that you test this every now and then by running the gauge over the set psi to blow off the valve to make sure it’s working properly.
Now my tank is rated to be used at 80psi and the government required test psi on the tank would be much higher so there is little worry at this time.
Ok, back to the topic.
First, let's see just what we have behind that valve!
Remove the valve by loosening that lock nut against the fitting and unscrew the entire thing. You will be left with parts that look like this:
With the parts laid out, they look like this:
The plunger seats against the inside of the fitting here:
With this valve you CAN NOT remove the housing and replace it with a new brass "T" fitting because the relief valve is part of the fitting that comes with the tank.
The psi is set by how much preasure it takes to push this spring away and allow the air to leak out. You might be able to replace the spring if you are not able to achieve the psi you want, but I would highly recomend you replace the relief valve and the fitting with a better one instead.
Here is the valve ready to ba adjusted. All that is needed is to hand screw the "cap" into the fitting and lock it in place with the lock nut. On mine, to achieve 55psi, I had to insert the cap all the way in and lock it there.
Here is what mine looked like adjusted to blow off at 55psi, note how far it is inserted into the housing. This is indeed how these are adjusted, so don't feel that this is a "hacked fix", but the proper set up for a relief valve.
I hope this helps some others to set up their tank beter. Feel free to ask if you have any questions!!
