Graco Monark Instructions-Parts List Manual page 5

Pressure Relief Procedure
WARNING
SKIN INJECTION HAZARD
Fluid under high pressure can be in-
jected through the skin and cause seri-
ous injury. To reduce the risk of an injury
from injection, splashing fluid, or moving parts, fol-
low the Pressure Relief Procedure whenever you:
D are instructed to relieve the pressure,
D stop spraying/dispensing,
D check or service any of the system equipment,
D or install or clean the spray tips.
1. Lock the gun trigger safety.
2. Close the bleed-type master air valve (required in
your system).
3. Unlock the gun trigger safety.
4. Hold a metal part of the gun firmly to a grounded
metal waste container and trigger to relieve the
fluid pressure.
5. Lock the gun trigger safety.
6. Open the pump drain valve (required in your
system), having a container ready to catch the
drainage.
7. Leave the drain valve open until you are ready to
spray again.
If you suspect that the spray tip or hose is completely
clogged, or that pressure has not been fully relieved
after following the steps above, very slowly loosen the
tip guard retaining nut or hose end coupling and relieve
pressure gradually, then loosen completely. Now clear
the tip or hose.
Service
A bleed-type master air valve is required in your
system, to reduce the risk of serious injury includ-
ing injury from moving parts if you are adjusting or
repairing the air motor.
The bleed-type master air valve relieves air trapped
between this valve and the motor after the air
regulator is shut off. Trapped air can cause the
motor and pump to cycle unexpectedly. Locate the
valve close to the pump, downstream from the air
regulator.
The piston in the air motor, located behind the air
motor plates, moves when air is supplied to the
motor. Moving parts can pinch or amputate your
fingers or other body parts. Therefore, never
operate the pump with the air motor plates re-
moved.
Restarting a Stalled Motor
To reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 5.
Never exceed 180 psi (12 bar, 1.2 MPa) air supply
pressure to the air motor. Exceeding this pressure
may cause the air motor to stall with the air transfer
valves stuck at mid position, making the air motor
inoperative.
To reseat the air transfer valves and restart a stalled
motor, relieve the air supply pressure to the motor by
closing the bleed-type master air valve. If the air
transfer valves fail to reseat, screw the cap nut (24)
out of the cylinder (23), pull up on the trip rod (29) and
screw the cap nut back into the cylinder. See Fig. 2.
Be sure the air supply pressure is less than 180 psi (12
bar, 1.2 MPa) before opening the bleed-type master air
valve.
WARNING
WARNING
WARNING
CAUTION
307141 5