![Graco 237–428 Instructions-Parts List Manual Download Page 6](http://html1.mh-extra.com/html/graco/237-428/237-428_instructions-parts-list-manual_2252101006.webp)
6
308-493
Operation
I.
Pressure–relief procedure.
The system remains pressurized until the pressure
is relieved manually. To reduce the risk of a serious
injury from pressurized fluid, accidental spray from
the gun, or splashing of any fluid, follow the pres-
sure relief procedure at these times:
D
You are instructed to relieve the pressure.
D
You stop spraying.
D
You check or service any system equipment.
D
You install, clean or change the spray nozzles.
WARNING
1.
Be sure the air regulator for the pump is still open.
2.
Turn off the ES On/Off valve lever, if you are using
an electrostatic spray gun.
3.
Trigger the spray gun to relieve the pressure.
4.
Open the fluid recirculating valve, if you have a
pail–mounted system.
II.
Prime the system.
1.
Follow the priming procedure given in the spray–
system instruction manual.
2.
After the first gun and hose are primed, decrease
the air pressure for the pump to 20 to 30 psi (1.4 to
2.1 bar).
3.
Repeat the priming procedure for the second gun
and hose.
III.
Set the fluid and air pressure.
1.
Be sure the air regulators to both guns are closed.
2.
Set the fluid and air pressure to the first gun as
instructed in your spray–package manual.
3.
Repeat the procedure for the second gun, but this
time use the new air regulator (3).
4.
Simultaneously test the spray pattern again for
both guns. Make any final adjustment that may be
needed.
IV.
How to flush the system.
1.
Follow the flushing procedure in your spray–sys-
tem instruction manual, using only one gun. Stop
when you reach the step that instructs you to trig-
ger the gun and run the pump until air comes from
the gun.
2.
Set the first gun aside.
3.
Flush the second gun, starting at the step that
instructs you to hold the gun against a grounded,
metal waste–pail.
4.
When both guns are flushed, follow the step that
instructs you to hold the gun against a grounded,
metal waste–pail.
5.
Relieve the pressure.