308155 9
Operation
Pressure Relief Procedure
INJECTION HAZARD
The system pressure must be manually
relieved to prevent the system from
starting or dispensing 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
D Are instructed to relieve the pressure
D Check or service any of the system equipment
D Install or clean the nozzle
WARNING
1. Shut off the hydraulic power supply.
2. Close the supply line shut-off valve (L in Fig. 1).
3. Open the dispensing valve to relieve pressure.
4. Open the pump outlet drain valve, and have a
container ready to catch the drainage.
5. Close the return line shut-off valve (H).
NOTE: Leave the drain valve open until you are ready
to dispense again.
If you suspect that the nozzle or hose is completely
clogged, or that pressure has not been fully relieved
after following the steps above, very slowly loosen the
hose end coupling to relieve pressure, then clear the
obstruction.
Before You Start the Pump
1. Check the hydraulic fluid level in the hydraulic
power supply before each use, and add fluid as
necessary to fill the lines.
CAUTION
Always use Graco approved hydraulic oil or equiv-
alent, Part Numbers 169236 (5 gallon) or 207428
(1 gallon). Do not substitute lower grade oil.
2. Flush the pump before you use it for the first time
to remove the light oil that was left in after factory
testing to protect the pump from corrosion. Be sure
the solvent used is compatible with the fluid to be
pumped and the pump wetted parts. See
Technical Data on page 26. Flush until clean
solvent comes from the outlet hose.
To Start the Pump
1. Turn on the hydraulic power supply.
2. Open the return line shut-off valve (H), and slowly
open the hydraulic supply shut-off valve (L).
3. Adjust the flow control valve (Q) to limit the
hydraulic flow to no more than 3 gpm (11 lpm),
which is approximately 60 cycles per minute.
NOTE: If Graco Part No. 236864 hydraulic fluid
control is used, no adjustment is necessary.
4. By adjusting the pressure reducing valve (N),
adjust the hydraulic inlet pressure from 50 to 1500
psi (0.34 to 10 MPa, 3.4 to 102 bar) for models
239882, 224741, and 224742. Increasing the inlet
pressure increases the outlet pressure.
Decreasing the inlet pressure decreases the outlet
pressure.
NOTE: For model 237653, adjust the hydraulic
inlet pressure from 50 to 1000 psi (0.34 to 7 MPa,
3.4 to 69 bar).
5. Always use the lowest pressure possible to obtain
the desired results. This reduces pump wear.
Never allow a pump to run dry of the fluid being
pumped. A dry pump quickly speeds up and can
damage itself. If it speeds up, shut off the power
supply to the reciprocator immediately. Refill the
supply container, and prime the pump to eliminate
air.
To prevent the pump from running dry, use a low-
level cutoff valve (X). See Fig.1 on page 5.
CAUTION
CAUTION
Maximum Working Temperature
Do not exceed 130_ F (54_ C) hydraulic oil tem-
perature. The reciprocator seals will wear faster
and leakage may occur if the pump is operated at
higher oil temperatures.
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