![background image](http://html1.mh-extra.com/html/graco/e-208997/e-208997_instructions-parts-list-manual_2251115003.webp)
Installation
307107P
3
Installation
Installing the Back Pressure
Valve
Install the back pressure valve in the spray gun return
line. See Fig. 1.
Connect the line to the 1-1/4 in. npt(f) inlet and outlet.
Make sure the flow direction agrees with the IN and
OUT markings on the valve body.
The back pressure valve is adjustable to control the fluid
pressures in a circulating system from 5 to 200 psi
(0.035 to 1.4 MPa, 0.35 to 14 bar).
If more than one spray station is used, install the back
pressure valve in the fluid supply line after the last sta-
tion. This will help maintain proper circulating pressures
in the system.
Operation
NOTE:
The back pressure valve controls pressure
ahead of its intake.
Turn the adjusting screw
clockwise
to increase pressure
and
counterclockwise
to decrease pressure.
Adjust the pump pressure and back pressure valve for
the best spraying combination and for proper circulation
of fluid.
Flush the back pressure valve with a compatible solvent
whenever the rest of the system or unit is being flushed.
Open the back pressure valve before flushing by turning
the screw
counterclockwise
.
F
IG
. 1
A
B
C
D
E
F
G
8719A
KEY
A
Fluid supply line
E
Adjusting screw
B
Air spray gun
F
Back pressure valve
C
Fluid pressure regulator
G
Fluid return line
D
Air supply line
NOTICE
Handle the back pressure valve with care to avoid
damaging the diaphragm.