Graco 237-004 Instructions-Parts List Manual page 10

7. If the pump is hard to prime, follow steps 1 to 4.
Place a waste container under the fluid drain valve
and open the valve. Slowly open the air regulator.
Run the pump slowly until it primes. Shut off the air
regulator; the pump will stall. Quickly close the
drain valve. Continue with step 5 or 6.
8. Relieve the pressure and install a spray tip and
tip guard.
9. Unlock the gun trigger safety, start the pump, and
spray a test pattern to check the atomization and
pattern. Relieve the pressure before making any
adjustments to the spray tip or system.
10. Adjust the fluid pressure regulator (K), back pres-
sure regulator (M), and pump air input pressure for
the best spraying combination and proper circula-
tion of the fluid. Record the regulator and air
pressure settings for future reference.
WARNING
To reduce the risk of overpressurizing the pump,
which can cause a component to rupture and result
in serious injury, NEVER exceed 100 psi (0.7 MPa,
7 bar) MAXIMUM AIR PRESSURE to the pump.
Reduce the air pressure, which reduces the fluid
outlet pressure, if any fluid line accessory is not
rated to withstand the maximum working pressure
of this pump.
306–694
Operation
11. Adjust the air line lubricator (B) and pump runaway
valve (A). See the instructions supplied with them.
12. Lock the gun trigger safety whenever you stop
spraying, even for a moment. Always relieve the
pressure when shutting down for any period of
time.
13. 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 (A), which shuts off the air supply to
the pump if the pump accelerates beyond the
pre–set speed, is available. See the Typical Instal-
lation on page 6. 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.