TM 5-4310-277-14
(4) When pressure adjustments are com-
(1) Clean all parts with cleaning solvent, Fed-
pleted, tighten all locknuts on the pilot valve. Stop
eral Specification P-D-680, and dry thoroughly.
the compressor.
(2) Inspect all parts for cracks, breaks, wear,
i. Adjustment, Pilot Valve (Model HGR5-
or damage. Replace a damaged part.
8M-6).
g. Assembly and Installation, Pilot Valve.
(1) Start the compressor. Allow compressor to
(1) Reassemble the pilot valve as follows:
build up tank pressure. Observe the pressure on
pressure gage. When the pilot valve actuates, un-
(7) in the body (9); install the stud (6).
loading compressor. This is the "cut-out" pressure
(b) Install stem (5), spring (4) and adjust-
and should be approximately 175 psi. To change cut-
ing screw (3); secure with collar (2) and locknut (1).
out pressure, turn pressure adjusting (7, fig. 4-20.1)
clockwise to increase pressure, and counter-
(2) Install the assembled valve and bracket as
clockwise to decrease pressure.
illustrated in Figure 4-11.
(2) Bleed off air from tank until pilot valve is
(3) Reconnect tubing to pilot valve.
actuated (starting the compressor to pump) observe
g.1. Assembly and Installation, Pilot Valve,
the tank pressure at this time. It should be approxi-
(Model HGR5-8M-6).
mately 145 psi (10.1935 kg per sq cm). This is the
(1) Reassemble the pilot valve as follows:
"cut-in" pressure.
body (2), and stem (4).
(3) To adjust differential pressure (difference
between cut-in and cut-out pressure), hold lock-nut
(b) Install spring (3) and nut (1).
(1) closest to the body of the valve so that it does not
(c) Install O-ring (8), cap (9), adjustment
move, then turn the large nut on the cap (9) very
nut (6), and pressure adjusting nut (7).
slightly clockwise to increase the differential, and
(d) Install the assembled valve and bracket
illustrated in Figure 4-11.
counter-clockwise to decrease it.
(4) When pressure adjustments are complete,
h. Adjustment, Pilot Valve.
tighten all locknuts on pilot valve. Stop the
(1) Start the compressor. Allow compressor to
compressor.
buildup tank pressure to desired cut-out pressure
(approximately 175 psi) (12.3025 kg per sq cm). The
4-27. Exhaust Manifolds
cut-out pressure may be changed by loosening the
a. Removal. Stop the air compressor, and release
locknut (1, fig. 4-20) and turning adjusting screw
all air from the compressor by opening the drain-
clockwise to increase pressure and counter- clock-
cock. Disconnect tubing from the high pressure and
wise to decrease pressure.
haust manifolds as illustrated in Figure 4-11.
(2) Bleed off air until pilot valve is actuated
noting the tank pressure at this point. It should be
b. Cleaning and Inspection.
approximately 145 psi (10. 1935 kg per sq cm).
(3) To adjust differential pressure, unlock
nut, turn adjusting barrel counterclockwise to de-
crease differential. This will lower top pressure. To
Dry cleaning solvent, P-D-680, used to
increase differential, turn barrel clockwise. To
clean parts is potentially dangerous to
change differential on low side, two adjustments
personnel and property. Avoid re-
are necessary. Unlock nut (1, fig. 4-20), turn adjust-
peated and prolonged skin contact.
ing screw counterclockwise. This will also lower top
Do not use near open flame or exces-
pressure. To adjust top pressure, unlock nut, and
sive heat. Flash point of solvent is
turn adjusting barrel, clockwise. Precision setting
100F. (38C. ) - 138oF. (59C. ).
of differential pressure may require slight adjust-
ing of adjusting screw and/or adjusting barrel.
(1) Clean all parts with cleaning solvent, Fed-
eral Specification P-D-680, and dry thoroughly.
(2) Inspect the manifolds for cracks, breaks,
CAUTION
or dents. Inspect all threaded fittings for damaged
Never leave adjusting barrel, screwed
threads.
to bottom position.
Change 1
