
308150P 9
Operation
Pressure Relief Procedure
1. Lock the gun/valve trigger safety.
2. Shut off the air supply to the pump.
3. In air-powered systems, close the bleed-type
master air valve (required in your system).
4. Unlock the gun/valve trigger safety.
5. Hold a metal part of the gun/valve firmly to the side
of a grounded metal pail, and trigger the gun/valve
to relieve pressure.
6. Lock the gun/valve trigger safety.
7. Open the drain valve (required in your system)
and/or the pump bleeder valve, having a container
ready to catch the drainage.
8. Leave the drain valve open until you are ready to
spray/dispense again.
If you suspect that the spray tip/nozzle 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, nozzle, or hose end
coupling and relieve pressure gradually, then loosen
completely. Now clear the tip/nozzle or hose.
Packing Nut/Wet-Cup
Fill the packing nut/wet-cup (2) 1/3 full with Graco
Throat Seal Liquid (TSL) or compatible solvent. See Fig.
4. Using the supplied wrench (104), adjust the packing
nut weekly so it is just snug; do not overtighten.
Follow the Pressure Relief Procedure above before
adjusting the packing nut.
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 before using the pump.
Starting and Adjusting the Pump
Supply fluid to the pump, per the requirements of your
system.
Refer to Fig. 3 on page 7. Be sure the air regulator (F) is
closed. Then open the pump's bleed-type master air
valve (E). Hold a metal part of the spray gun/dispensing
valve (S) firmly to the side of a grounded metal pail and
hold the trigger open. Now slowly open the air regulator
until the pump starts.
Cycle the pump slowly until all the air is pushed out and
the pump and hoses are fully primed. Release the spray
gun/dispensing valve trigger and engage the safety
latch. The pump should stall against pressure when the
trigger is released.
If the pump fails to prime properly, open the bleeder
valve (35) slightly. Use the bleed hole on the underside
of the valve body (34) as a priming valve until the fluid
appears at the hole. See Fig. 4. Close the plug (35).
NOTE: When changing fluid containers with the hose
and gun already primed, open the bleeder valve plug
(35), to assist in priming the pump and venting air
before it enters the hose. Close the bleeder valve plug
when all air has been eliminated.
WARNING
INJECTION HAZARD
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:
• are instructed to relieve the pressure,
• stop spraying/dispensing,
• check or service any of the system equipment,
• or install or clean the spray tip/nozzle.
WARNING
For your safety, read the warning section FIRE
AND EXPLOSION HAZARD on page 5 before
flushing, and follow all the recommendations given
there.
WARNING
To reduce the risk of fluid injection, do not use your
hand or fingers to cover the bleed hole when
priming the pump.