First step would be to check for leaks and repair if present. Then turn the adjustment screw all the way out counterclockwise. The low pressure gauge pointer should drop to zero. Then slowly turn the adjustment screw clockwise until you acquire the pressure desired. If you adjust too high, back the screw up all the way and start over. The regulator will vent the low pressure port when you turn the screw counter clockwise completely. If you do not have any laeks, you should be able to adjust with all of your pressure valves open.
Scott Zuhse, Instructor
Micro Matic Dispense Institute