Recirculate Prior To Spraying Or Re-Prime After A Pump Runs Dry - Graco XP-H Series Operation, Repair, And Parts

Operation
Recirculate Prior to Spraying or
Re-Prime After a Pump Runs Dry
NOTE: Agitate, recirculate, and heat the material only
as necessary to avoid mixing air into the fluid.
Use the recirculation mode when heating the material is
required. Note the temperature at the top of the heater
(outgoing or back to the hopper). When the
thermometer reaches operating temperature, the
material is ready to spray.
If using a system that does not require heat,
recirculation is still required prior to spraying.
Recirculation ensures that any settled fillers are mixed
in, the pump lines are fully primed, and the pump check
valves are operating smoothly.
Recirculation also allows you to re-prime one side that
has run dry.
1. Follow Prime Empty System, page 31.
2. Close the dual shutoff handle (FE).
EC
FE
3. Ensure the recirculation hoses (U) are in the correct
hoppers (J).
J
4. Open the circulation valve handle (FC).
34
U
FC
5. For XP Systems:
a. Turn down air pressure regulator (MB) and then
open the main air shutoff valve (MA). Use the air
pressure regulator to slowly increase air pres-
sure to pumps until they start running slowly.
MB
MA
b. Run the pumps for a few minutes or until the
material has reached the desired temperature.
See Heat Fluid, page 34.
c. Close the motor air shutoff valve (MA).
MA
6. For XP-h Systems:
a. Turn down the pressure control knob and set
the pump valve on.
b. Slowly increase the pressure until the pumps
start running slowly.
c. Run the pumps for a few minutes or until the
material has reached the desired temperature.
See Heat Fluid, page 34.
d. Set the pump valve off.
Heat Fluid
To heat fluid evenly throughout the system:
1. Circulate the fluid at approximately 1/2 gpm
(10-20 cycles/min.) to raise the temperature of the
hoppers to 80-90 °F (27-32 °C).
2. Decrease the circulation rate to approximately
0.25 gpm (5 cycles/min.) to increase the heater
outlet temperature to match the spray temperature.
NOTE: Circulating the fluid too quickly without
decreasing the circulation rate will increase only the
hopper temperature. Similarly, circulating fluid too
slowly will increase only the heater outlet temperature.
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