Operation - Graco G Series Instructions-Parts List Manual

Pressure Relief Procedure
WARNING
PRESSURIZED EQUIPMENT HAZARD
The system pressure must be manually relieved to
prevent the system from starting or spraying
accidentally. To reduce the risk of an injury from
accidental spray from the gun, splashing fluid, or
moving parts, follow the Pressure Relief Procedure
whenever you:
• are instructed to relieve the pressure,
• stop spraying,
• check or service any of the system equipment,
• or install or clean the spray nozzle.
1. Shut off the air to the pump.
2. Close the bleed-type master air valve (required in
your system).
3. Hold a metal part of the dispensing valve firmly to the
side of a grounded metal pail, and trigger the valve to
relieve pressure.
4. Open the fluid drain valve (required in your system) to
relieve all fluid pressure, having a container ready to
catch the drainage.
5. Leave the drain valve open until you are ready to
dispense again.
If you suspect that the nozzle or hose is completely
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 nozzle or hose.
Flush the Pump Before Using
The pump was tested in lightweight oil, which was left in to
protect pump parts. To prevent contamination of the fluid
you are pumping, flush the pump with a compatible solvent
before using it.
To flush the pump, connect a short hose to the pump
outlet, insert the pump intake into a pail of compatible
solvent, direct the hose into a pail, and start the pump as
explained at right.
Cycle the pump slowly for at least 5 minutes, then stop and
disconnect the air hose. Push up on the ball of the intake
valve (J) to drain the lower part of the pump. See Fig. 4.
Turn the pump over to drain the upper part of the pump.

Operation

Fig. 4
Starting and Adjusting the Pump
1. Mount the pump and connect to a fluid supply as
explained on page 5.
2. See the INSTALLATION on page 6. Be sure the air
regulator (A) and bleed-type master air valve (D) are
closed.
3. Hold a metal part of the spray gun/dispensing valve
firmly to the side of a grounded metal pail and hold
the trigger open. Then open the pump's bleed-type
master air valve (D). Now slowly open the air
regulator (A) until the pump starts.
4. Run the pump slowly until all the air is pushed out of
the pump and hose. Always use the lowest pressure
necessary to get the desired results. Higher
pressures waste fluid and cause premature system
wear.
5. After all the air is purged, release the gun/dispensing
valve trigger. In a direct supply system, the pump will
start and stop as the gun/valve is opened and closed.
In a circulating system, the pump will run continuously
and will speed up or slow down as supply demands,
until the air supply is shut off.
Never allow the pump to run dry of the fluid being pumped.
A dry pump will quickly accelerate to a high speed,
possibly damaging itself. If your pump accelerates quickly,
or is running too fast, stop it immediately and check the
fluid supply. If the supply container is empty and air has
been pumped into the lines, refill the container and prime
the pump and the lines with fluid, or flush and leave it filled
with a compatible solvent. Be sure to eliminate all air from
the fluid system.
Shutdown and Care of the Pump
For overnight shutdown, follow the Pressure Relief
Procedure Warning at left. Always stop the pump at the
bottom of the stroke to prevent the fluid from drying on the
exposed displacement rod and damaging the throat
packings.
J
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