Pressure Control Adjustment - Graco ULTRA 500 231-032 Instructions-Parts List Manual

USE EXTREME CAUTION WHEN PERFORMING THIS ADJUSTMENT PROCEDURE to reduce the risk of a
fluid injection injury or other serious bodily injury which can result from component rupture, electric shock, fire,
explosion, or moving parts.
This procedure sets the sprayer to 2750 psi (195 bar)
MAXIMUM WORKING PRESSURE and sets the
overpressurization switch (microswitch) to approxi-
mately 3600 psi (242 bar).
Perform this procedure whenever the pressure con-
trol assembly is removed and reinstalled or replaced,
or a new circuit board is installed.
Improper adjustment can cause the sprayer to over-
pressurize and result in component rupture, fire or ex-
plosion. It may also prevent the sprayer from obtaining
the maximum working pressure, resulting in poor
sprayer performance.
WARNING
To reduce the risk of serious injury, follow the illus-
trated Pressure Relief Procedure warning on
page 24 whenever you are instructed to relieve
pressure.
NOTE: Read the GENERAL REPAIR INFORMATION
on page 24 before doing this procedure.
Required tools for adjustment procedure
3/8 in. nut driver or 3/8 in. socket wrench
1/4 in. open end wrench
7/16 in. open end wrench
0 – 5000 psi, oil-filled test gauge, Part No. 102–814
Pail of clean water
Mineral spirits
NEW 3000 psi (210 bar) high pressure spray hose,
Part No. 223–541
1. Relieve pressure.
2. See the above list of tools and equipment needed.
Remove the plug (A) from the top of the fluid filter and
install the fluid-filled pressure gauge. See Fig 30–1.
Connect the gun to the new test hose and connect
the hose to the sprayer outlet.
307–758
30

PRESSURE CONTROL ADJUSTMENT

WARNING
NEVER try to increase the sprayer's maximum work-
ing pressure of 2750 psi (195 bar) by performing these
adjustments in any other way. Normal operation of the
sprayer at higher pressures may result in component
rupture, fire or explosion. To perform this adjustment,
however, the sprayer pressure must be temporarily in-
creased above the normal working pressure.
Use a new 50 ft (15.2 m) spray hose rated for at least
2750 psi (195 bar) MAXIMUM WORKING PRES-
SURE. A used, under–rated hose could develop a
high pressure leak or rupture.
3. Remove the pressure control cover (62).
4. Place the pump suction tube in a pail of clean water.
5. Be sure the gun safety latch is engaged.
A
62