308116 9
Operation/Maintenance
Starting and Adjusting the Pump
See the Typical Installation on page 5. Be sure the
air regulator (E) and bleed–type master air valve (D)
are closed. DO NOT INSTALL THE SPRAY TIP YET!
Connect a suction hose (N) to the pump’s fluid inlet.
Hold a metal part of the spray gun (M) 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 until the
pump starts, about 40 psi (0.9 MPa, 2.8 bar).
Cycle the pump slowly until all the air is pushed out
and the pump and hoses are fully primed. Release the
spray gun trigger and lock the safety latch. The pump
should stall against pressure when the trigger is re-
leased.
Follow the Pressure Relief Procedure on page 8,
then install the spray tip in the gun.
With the pump and lines primed, and with adequate air
pressure and volume supplied, the pump will start and
stop as the spray gun 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.
Use an adequately sized air regulator (E) to control the
pump speed and the fluid pressure. Always use the
lowest air pressure necessary to get the desired
results. Higher pressures waste fluid and cause pre-
mature wear of the pump packings and spray tip.
WARNING
To reduce the risk of overpressurizing your system,
which could result in component rupture and cause
serious bodily injury, NEVER exceed the maximum
incoming air pressure given on your pump or in the
Technical Data on pages 22–23.
Keep the packing nut/wet-cup (2) filled with Graco
Throat Seal Liquid (TSL) or compatible solvent, to help
prolong the packing life. Adjust the packing nut weekly
so it is just tight enough to prevent leakage; do not
overtighten. See Fig. 3. Always follow the Pressure
Relief Procedure on page 8 before adjusting the
packing nut.
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. A pump runaway
valve (B), which shuts off the air supply to the pump if
the pump accelerates beyond the pre–set speed, is
available. See the Typical Installation on page 5. 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 on page 8. 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.
