um Unverferth 2750, Руководство оператора и каталог запасных частей, Страница: 17 / 112

1-5
Operation
ADJUSTING HYDRAULIC PRESSURE
RELIEF VALVE
:
a. This unit has an adjustable relief valve
which can be adjusted for optimum op-
eration. It is pre-set at the factory to by-
pass the system once the hydraulic fl uid
pressure exceeds 1500 psi. This is the
optimum setting for this unit. Adjusting
the relief to higher settings may give un-
satisfactory results.
IMPORTANT: This unit can be adjusted to pro-
vide system pressures from 1,000 PSI up to
2500 PSI. When adjusting the relief to allow
the system to exceed 1500 PSI, the engine
will tend to bog down due to the load and in
high load applications, may cause the engine
to stall.
b. Remove the Pump Cover by loosening
the hex capscrew and lock washer se-
curing it.
1 1/8” Wrench
Mark position of 1,500
psi setting for reference
!
"
#$
Decrease
Pressure
Increase
Pressure
5/16” Allen Wrench
c. Remove the relief adjustment cover by
using two wrenches, 1 1/8” and a 1”.
d. Mark the location of the set screw in re-
lationship to the valve to know where the
1,500 psi setting is, with a paint pen or
permanent marker.
e. With the 1 1/8” wrench and a 5/16” Allen
wrench, loosen jam nut securing the ad-
justment screw.
f. Looking at the head of the adjustment
screw. Rotate clockwise to increase relief
pressure, counter-clockwise to decrease
as shown.
IMPORTANT: It will be necessary to install a
pressure gauge into the hydraulic system to
accurately adjust the relief valve.
g. Once desired setting is reached. Be sure
to lock down adjustment screw with jam
nut and replace the washer and adjust-
ment screw cap. Replace and tighten
pump cover.
1” Wrench
Pressure Relief
Valve
Remove Pump
Cover