Graco 220-569 Heat Pump User Manual


 
307-809 15
Maintenance
The operating conditions of your particular system
determine how often maintenance is required. Estab
-
lish a good maintenance schedule during the first
several weeks of operation by recording when and
what kind of maintenance is needed, and then deter
-
mine a regular schedule for checking your system.
Y
our maintenance schedule should include the follow
-
ing:
Flushing
WARNING
FIRE AND EXPLOSION HAZARD
Before flushing, read the section
FIRE
AND EXPLOSION HAZARD
on page
5. Be sure the entire system and flush
-
ing pails are properly grounded. Refer to
Grounding
on page 7.
1.
Flush before shutting down the system for an
extended period of time.
2.
Flush before repairing the pump, if possible.
3.
Flush before the fluid you are pumping can dry out,
settle or set up in the pump and hoses.
Packing Nut Tightness
The
packing nut (21) should be tight enough to stop
leakage, but no tighter. Overtightening compresses
and damages the packings, and may cause the pump
to leak, reducing performance. See Fig. 4.
T
o check the adjustment of the packing nut, first re
-
lieve fluid pressure. If you have a torque wrench,
tighten the packing nut to 34–40 N
S
m (25–30 ft–lb).
Excessive Leaking at Throat
To
monitor leaking at the throat, remove one of the
small plugs (31) from the packing nut (21). Place one
end of a drain tube in the hole and the other end in a
container
. See Fig. 4. Monitor the drainage. If it seems
excessive, and tightening the packing nut does not
help, replace the throat packings. See page 20.
Fig. 4
01925
21
3131
1
Torque
to 34–40 N
S
m
(25–30 ft–lb).
1