Service; Pressure Relief Procedure - Graco PrecisionFlo XL Manual

Pressure Relief Procedure

This procedure describes how to relieve pressure
between the PrecisionFlo metering valve assembly
and the automatic dispense valve. See your supply
unit or system documentation for instructions on
relieving pressure for the entire dispensing system.
Use this procedure whenever you shut off the dispense
valve and before checking or adjusting any part of the
system, to reduce the risk of serious injury.
WARNING
INJECTION HAZARD
The system pressure must be manually
relieved to prevent the system from
starting or spraying accidentally. 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:
D are instructed to relieve the pressure
D stop spraying/dispensing
D install or clean the nozzle
D check or service any of the system
equipment.
PRESSURIZED FLUID HAZARD
High pressures can cause serious injury.
Be sure to open the dispense valve
during system heat-up to alleviate
pressure which might occur in the sys-
tem due to material expansion.
WARNING
INJECTION HAZARD
The PrecisionFlo XL module pressure
must be manually relieved to prevent the
module from starting or spraying
accidentally. To reduce the risk of an
injury including fluid injection, splashing
in the eyes or on the skin, or injury from
moving parts, always follow the
Pressure Relief Procedure whenever
you:
D are instructed to relieve the pressure
D check or service any of the system
equipment
D shut off the pump or install or clean
the spray tip.

Service

1. Shut off the fluid supply to the metering valve.
2. Shut off power and air to the fluid supply systems
3. Place a waste container beneath the fluid drain
valve, which is located at the filter. Place a waste
container beneath the dispense device.
4. Slowly open the drain valves located at each filter,
to relieve pressure.
5. Leave the drain valves open until you are ready to
pressurize the system again.
6. In Manual Dispense Mode, touch and hold the
Dispense Gun button. This will actuate the meter-
ing valve and the dispensing device and relieve
fluid pressure.
7. Refer to Fig. 10 and perform the following steps to
open the dispense device and relieve fluid pres-
sure:
a. To relieve fluid pressure, manually actuate the
plunger on the solenoid (C) that opens the
dispense device.
b. Continue actuating the plunger until all pres-
sure is purged from the system between the
needle and the dispense device before pro-
ceeding.
Fig. 10
NOTE: If, after following the steps above, you suspect
that a valve, hose, or the mixer dispenser nozzle has
become completely clogged, or that pressure has not
been fully relieved, VERY SLOWLY loosen the mixer
shroud or hose end coupling and gradually relieve the
pressure. Then loosen completely and clear the tip,
valve, or hose. DO NOT attempt to pressurize the
system until the blockage is cleared.
To dispense
valve
C
309375 13