Ingersall rand T30

[Don_Papenburg]

Does anyone know how the air pipe terminates on a two stage 3cylinder T30 ? the pipe in ? is the one that runs from the air pressure switch to the first intake cylinder head top to the second cylinder top to the second stage cylinder top and then mine ends as a crimped tube that leaks air .  There is a needle valve in the line where it comes out of the pressure switch.  It is a small tube about 1/4" . Compressor was built in the 60s

[sawguy21]

That line is part of the unloader system. When the tank reaches the preset pressure, the lever on the pressure switch pushes the pin and allows air into the line, the pressure holds the inlet valves open and 'unloads' the head until the tank pressure drops and the unloader kicks out. Each head should have a fitting for a branch of this line. Sounds like somebody used a tee instead of an elbow on the second stage head.

[Don_Papenburg]

Thanks for the reply .  The line runs from one sidof a cylinder head to the next head . But what stumped me was the second stage head , it has a fitting exiting the head with a short tube crimpcut and no place for it to attach if it were longer. That is were the air  leaks.   One other stumper is the needle valve in the line just before the line enters the first cylinder.  If this for unloader duty than it should not be there.  Then the fitting on the second stage that leads to nowhere should be replaced with aplug?