I installed my airhorns with the blue digital hornblasters guage. The problem is when the gauge reads around 50 psi my 145 psi pop off valve blows. I called hornblasters and they said be sure to have the sending unit set at 150 (which makes sense). I went in the settings and verified it was set at 150. I even reset it and it still only gets to ~50 psi before releasing. Anyone else had this problem? Thanks in advance.
I have a 150 psi safety valve and my dual Viair 400c units cut off at 145 psi. The safety valve never blows, even when the tank gets up to 148 psi on a hot day. My Air Zenith digital gauge is always dead-accurate within +/- 1 psi.
But regardless of your gauge being accurate or not, this should effect when your compressors shut off. If you have the right pressure switch with a 145 psi cutoff or lower then the 150 psi safety valve should not blow. But I did read that most safety valves have a margin of error like +/-10% so maybe your valve is just on the low side, or maybe it has been worn to the point of blowing too soon.
Thanks for the replies. I will try setting the sending unit up at 400 psi and see what happens. Hopefully it will read true.
Oh also I don’t have a pressure switch installed. I just use my truck upfitter switch to cutoff the compresser when it gets to ~145. I was mistaken and thought a 150 psi system was max pressure and that I shouldn’t let the pressure exceed that. Which Is why I got a 145 psi pop off valve.
You should ALWAYS run the compressors with a pressure switch… I use my upfitter switches for the compressors as well, however, I have a pressure switch installed just incase I don’t get to turning them off (I always leave them on anyway) but you should run them with a pressure switch because if you don’t, it’ll void the warranty…