
10 309022
Operation
Pressure Relief Procedure
WARNING
INJECTION HAZARD
The system pressure must be manually
relieved to prevent the system from
starting or spraying accidentally. Fluid
under high pressure can be injected through the
skin and cause serious injury. To reduce the risk of
an injury from injection, splashing fluid, or moving
parts, follow the Pressure Relief Procedure
whenever you:
Dare instructed to relieve the pressure,
Dstop spraying,
Dcheck or service any of the system equipment,
Dor install or clean the spray tip.
1. Fig. 6. Shut off power to the pump by closing the
bleed-type master air valve (E, required in the
system).
2. Fig. 3. Unlock the gun trigger safety.
3. Hold a metal part of the gun firmly to the side of a
grounded metal waste container and trigger the
gun to relieve the fluid pressure.
4. Lock the gun trigger safety.
5. If you suspect that the spray tip is completely
clogged or that pressure has not been fully re-
lieved after following the steps above, very slowly
loosen the air cap retaining ring to relieve pressure
in the cavity between the ball/seat shutoff and the
plugged tip. Clear the tip orifice.
6. If you suspect that the gun fluid filter or the fluid
hose is completely clogged or that pressure has
not been fully relieved after following the steps
above, very slowly loosen the hose end coupling
at the gun and relieve pressure gradually. Then
loosen completely to clear the obstruction.
9255A
Fig. 3
Gun Trigger Safety Unlocked
Gun Trigger Safety Locked
WARNING
If you suspect that the spray tip or hose is com-
pletely clogged, or that pressure has not been fully
relieved after following the steps above, very
slowly loosen the hose end coupling and relieve
pressure gradually, then loosen completely. Now
clear the tip or hose.
Wet Cup
Fig. 6. Before starting, fill wet cup (M) 1/3 full with
Graco Throat Seal Liquid (TSL) or compatible solvent.
WARNING
To reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure at left.
Flush the Pump Before First Use
The pump is tested with lightweight oil, which is left in
to protect the pump parts. If the fluid you are using
may be contaminated by the oil, flush it out with a
compatible solvent. See Flushing on page 14.