Operation/Maintenance
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:
are instructed to relieve the pressure,
stop spraying,
check or service any of the system equipment,
or install or clean the spray tips.
1.
Lock the gun/valve trigger safety.
2.
Shut off the air supply to the pump.
3.
Close the bleed-type master air valve (required in
your system).
4.
Unlock the gun/valve trigger safety.
5.
Hold a metal part of the gun firmly to the side of a
grounded metal pail, and trigger the gun to relieve
pressure.
6.
Lock the gun/valve trigger safety.
7.
Open the drain valve (required in your system),
having a container ready to catch the drainage.
8.
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 (2) 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 the pressure, then
torque the nut to 136–149 N.m (100–110 ft-lb) using
the supplied wrench (110). Do this whenever neces-
sary. Do not overtighten the packing nut.
04143
Fig. 3
110
2
1
Model
237–516
Shown
1
Torque to 136–149 N.m
(100–110 ft-lb)
