I have had 2 experiences this week that have shown me how little I know and understand about regulators. My experience goes as follows, install and adjust. I have never looked much into the operation nor trouble shooting of regs.
The first job I was on I was doing a typical PM on 2 120ton Intellipaks with 850MBTU furnaces. I found my outlet pressure was low (2.8 IWC) due to a low inlet pressure (5.5 IWC dynamic) when the min inlet required is 7 IWC. We have been doing the PM for years and never had a low inlet. So I suspect the regulator. It is a 2psi x 7 IWC reg that is maxed out. The only thing I found was that the 8 screws on the diaphram body were loose, which in my logic would mean that dirt and/or moisture could have entered the diaphram and caused a failure. Now I do not know if this is a justified diagnosis because of my lack of knowledge on regulators. What am I missing here or where is my logic wrong?
The other job was a call that every gas appliance had stopped working in this warehouse. I get up to the first UH and it is trying to light the pilot but can't. I hear the gas pouring out of the pilot tube and know this isn't right. I put my manometer on the inlet of the gas valve and read 105 IWC. I didn't believe it so went to the next UH, then to the water heater, 105 IWC . I grabbed my magnohelic because that can't be right. I blows right past the 3 psi (84 IWC). I have to suspect that the gas meter regulator has failed. I did not see any signs of tampering or adjustment done. Its hard for me to believe this is how a regulator fails, I would assume a small pinhole in the diaphram or something alont those lines that would cause improper opreation but not complete failure to regulate. I should know more once Xcel gets out there and addresses it.
Any knowledge and input would be appreciated and I could really use some good literature.