Graco Inc. 237-296 - Manual (Page 8)

8 308-425
Operation
Pressure Relief Procedure
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,
D check or service any of the system equipment,
D or install or clean the spray tips.
1. Lock the gun trigger safety.
2. Close the red-handled bleed-type master air valve
(F, required in your system).
3. Unlock the gun trigger safety.
4. Hold a metal part of the gun firmly to the side of a
grounded metal pail, and trigger the gun to relieve
pressure.
5. Lock the gun trigger safety.
6. Open the drain valve (D, required in your system),
having a container ready to catch the drainage.
7. Leave the drain valve open until you are ready to
spray again.
If you suspect that the spray tip or hose is completely
clogged, or that pressure has not been fully relieved
after following the steps above, very slowly loosen the
tip guard retaining nut or hose end coupling and relieve
pressure gradually, then loosen completely. Now clear
the tip or hose.
Packing Nut/Wet-Cup
Before starting, fill the packing nut (K) 1/3 full with
Graco Throat Seal Liquid (TSL) or compatible solvent.
See Fig. 3.
WARNING
To reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure at left.
The packing nut is torqued at the factory and is ready
for operation. If it becomes loose and there is leaking
from the throat packings, relieve pressure, then
torque the nut to 100–110 ft-lb (136–149 N.m) using
the supplied wrench. Do this whenever necessary. Do
not overtighten the packing nut.
Flush the Pump Before First Use
The pump is tested with lightweight oil, which is left in
to protect the pump parts. If the fluid you are using
may be contaminated by the oil, flush it out with a
compatible solvent. See Flushing on page 10.
Using the Airless Spray Gun
Before operating the equipment, read the instruction
manual supplied with the gun.
Spray some test patterns before doing any finished
work. Refer to the gun manual for detailed information
on correct spraying technique.