API6D THROUGH CONDUIT EXPANDING GATE VALVE - AP400-405 SERIES
Australian Pipeline Valve - Installation, Operation and Maintenance Manual
22
8.6 EMERGENCY STEM SEAL PLASTIC PACKING INJECTION
APV Expanding Gate Valves are equipped with a packing fitting usually having a ball check as illustrated
in Figure 3. In the event of damage to the stem packing which causes a leak, plastic stick packing can be
injected into the packing box to increase packing box pressure and eliminate the leakage. A rachet with a
socket, which fits the hex head on the packing fitting stinger, is recommended for this operation.
a) Remove the packing fitting injection stinger and insert a plastic packing stick into the fitting.
b) Run the stinger all the way in against the seat of the fitting.
c) Repeat injection of the plastic packing sticks to the extent necessary to stop the stem seal leakage.
8.6.1 Replacing the injectable packing
There may be occasions when the packing must be replaced. The valve must be in the fully closed
position. Bleed the valve body using the procedure in Section 8.5. Screw the injector screw in all the way
against the seat, then remove the injector screw from the fitting ONLY after being certain that the
internal ball check is fully seated and is sealing.
Remove the packing plug opposite the packing fitting. Inject packing into the packing box until the old
packing is discharged through the packing plug opening. Replace the packing plug, then inject packing
until reaching the appropriate pressure shown in the table below.
Note
Excessive packing injection may cause the valve stem to bind and/ or decrease the
life of the stem seals. DO NOT exceed the appropriate packing pressure in the table
below. Excessive packing pressure can cause the valve to be hard to operate and
may also shorten the life of the stem seal.
VALVE PRESSURE
CLASS
PACKING BOX
PRESSURE (psig)
150
1925
300
2600
400
2950
600
3675
900
4750
1500
6900
Do not remove the stinger if there is continuous leakage through the weep hole of
the packing fitting when the stinger is being backed out.
Figure 3
