Screwing the range nut counter-clockwise decreases the cut-out point. Note the pressure
gauge readings at which the compressor cuts-in and out and re-establish the differential
pressure setting if necessary. The differential pressure maybe increased by screwing the
differential nut clockwise. Backing off the nut will narrow the span. It is advisable to have
as wide a differential as possible to avoid frequent starting and stopping of the compressor.
Note the pressure gauge reading at which the compressor cuts out and re-establish this point
if necessary.
5-12. PILOT VALVE ADJUSTMENT. If
the pilot valve tube line is excessively hot,
it is a good indication that the pilot valve is
leaking and adjustment is required. To ad-
just the pilot valve, refer to Figures 5-11
and 5-12 and proceed as follows:
5-12.1. Stop the compressor. Remove the
pilot valve tube fitting and withdraw the
spring .'
5-12.2. With a small rod, push the plate
in against the resistance of the thrust pin
until the plate is firmly seated. Mark this
and Cut-Out Adjustment
position on the rod in line with the outer
edge of the pilot valve body. Now, permit
the thrust pin to push the plate away from
the seat as far as it will and also mark this
position on the rod.
5-12.3. The correct stroke, or measure-
ment between the two marks, is between
1/16" and 1/8". Should the measurement
be under 1/1 6", adjust for the proper stroke
by screwing the pilot valve body in a clock-
wise direction; should the measurement ex-
ceed 1/8", screw the body in a counter-
clockwise direction.
5-13. CHECK VALVE REPAIR. The check
valve (Figure 5-13) can be disassembled by
forcing the point of a screw driver between
I
the cap and body. To reassemble the valve,
put the spring and disc into the valve cap
and snap the cap and body together. Be
certain the disc is installed with its lapped
Unloader and Pilot Valve
side "up".
5-10
