Decrease, and if you dont have a pressure gauge on the compressor, put one on it'l help with the setting up. I do it on the run, but this aint for everyone
found this
Clockwise rotation of the screw increases the pressure, while a counter-clockwise rotation decreases the pressure. Ensure the compressor is unplugged and the tank is empty before adjusting. Step 7: Turn on the compressor and verify if the compressor motor stops when the pressure reaches the cut-out point.