Design YD, YS, & YSC UPPER WIPER (KEY 12) PACKING FOLLOWER (KEY 13)
PACKING RING (KEY 7)
LANTERN RING (KEY 8) PACKING BOX RING (KEY 11)
12A8188-A 12A7815-A 12A8173-A A2619-1
9.5 mm 12.7 mm 19.1, 25.4, OR (3/8 INCH) (1/2 INCH) 31.8 mm STEM STEM (3/4, 1, OR 1Ć1/4 INCH) STEM
TYPICAL (DOUBLE) ARRANGEMENTS Figure 4. Detail of PTFE/Composition Packing Arrangements
PACKING FOLLOWER
PACKING FOLLOWER
GRAPHITE RIBBON PACKING RING
GRAPHITE RIBBON PACKING RING 1
GRAPHITE 2 FILAMENT PACKING RING
1
1
1
GRAPHITE 2 FILAMENT PACKING RING
1
LANTERN RING
1
LANTERN RING
13A9775-B
14A3411-A
9.5 mm (3/8ĆINCH) STEM A2438-2 / IL
12.7 mm (1/2ĆINCH) STEM
13A9776-B
19.1 OR 25.4 mm (3/4 OR 1ĆINCH) STEM
SINGLE PACKING ARRANGEMENT
14A1849-B
14A2153-B
9.5 mm (3/8ĆINCH) STEM
PACKING BOX RING
1
1
1 PACKING BOX RING
12.7 mm (1/2ĆINCH) STEM
14A1780-B
19.1 OR 25.4 mm (3/4 OR 1ĆINCH) STEM
DOUBLE PACKING ARRANGEMENT
NOTE: 1
0.102 mm (0.004 INCH) THICK SACRIFICIAL ZINC WASHERS. USE ONLY ONE BELOW EACH GRAPHITE RIBBON RING.
2
HAS THE APPEARANCE OF A WOVEN OR BRAIDED RING.
Figure 5. Graphite Ribbon/Filament Packing Arrangements
CAUTION The exposed portion of the cage provides a guiding surface that must not be damaged during disassembly or maintenance. If the cage is stuck in the valve, use a rubber mallet to strike the exposed portion at several points around the circumference. Take proper care not to damage any sealing or seating
surfaces as nicks or scratches in these parts might cause leakage. 5. Loosen the packing flange nuts (key 5, figures 12 and 13) or packing flange cap screws (key 26, figure 15) and draw the valve plug and stem straight out the bottom of the bonnet. Lift all cage and seat parts off the valve plug and stem. If the stem for Design YD or YS requires replacing, drive the pin (key 6) out and unscrew the stem from the plug. If the stem for Design YSC requires replacing, remove the plug nut, disk retainers, spacers, and disk (keys 10, 7, 8, and 9). Drive the pin out and unscrew the stem (key 6B) from the valve plug bolt (key 6A).
7