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F-1031, Section 2115
Packing Adjustment
The pump packing is designed and adjusted to drip
slightly during operation. This is to cool and lubricate the
packing. It is desirable to adjust the stuffing box to main‐
tain a leakage rate of 10 to 120 drops per minute when
operating at a discharge pressure of 150 psi (10.3 bar).
Leakage through the braided flexible graphite (BFG) pack‐
ing may be at zero or diminish to zero leakage and may
not respond to loosening of the packing nuts to restore
leakage (see adjustment step 3). While the packing gland
and stuffing box and pump body may reach high temper‐
atures during this time, the impeller shaft will be protected
from heat damage.
CAUTION
Pump overheating hazard.
May cause damage to the pump.
Circulate enough water through the pump to prevent
overheating.
WARNING
!
Truck Movement Hazard. May result in serious per‐
sonal injury or death.
Stop the engine, set parking brake and chock the
wheels before going under the truck to adjust packing.
1.
Engage pump per appropriate operating instructions.
Operate the pump at 150 psi (10.3 bar) for ten (10)
minutes.
CAUTION
Observe the stuffing box drip rate from the side of the
truck.
2.
Observe leakage. Normal leakage is 10- 120 drops per
minute. (Leakage may be at zero or diminished to zero
occasionally).
3.
If drip rate is considered high, stop the engine and
tighten the packing gland nuts 1/2 to 1 flat (maximum
of 1/6 of a revolution). Make appropriate adjustments
starting with 1 flat, when approaching the final adjust‐
ment reduce to 1/2 flat. This reduces the possibility of
over tightening.
Tighten the gland nuts equally to
ensure that the packing gland goes on straight.
Gradually reducing leakage during the first hour of
operation will result in a better seal over a longer
period of time.
CAUTION
Stopping the leakage entirely at this point will cause
the packing to overheat.
4.
Operate the pump at 150 psi (10.3 bar) for 10 to 15
minutes to let packing run in, then observe the drip
rate.
WARNING
!
Packing Gland and Pump Body Temperature
Hazard. May result in serious burns.
Heat is dissipated through the cross-section of the
packing, transferring the heat to the packing gland
and pump body.
5.
Repeat steps 3 and 4 until the drip rate is acceptable.
NOTE: After adjusting the packing, the pump must
pass the following vacuum test described below.
