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