Flowserve Cast Globe Valves - Manual (Page 15)

Globe Valves FCD ADENIM0011-00
15
5.0 VALVE MAINTENANCE
(Continued)
5.4 Packing
Anchor/Darling Globe valves are supplied with John Crane 187-1 packing unless otherwise specified. When specially
ordered, valves are supplied with Graphoil packing which requires more specialized care in installation. The packing
manufacturers' instructions should be followed. The following packing installation procedures are for John Crane
187-1 or similar packing.
1. Unbolt gland bolts and raise gland flange and gland. These two parts may be held out of the way with wire or
twine. To prevent the loss of the two gland nuts, thread back on the gland bolts.
2. If the valve is being repacked, remove the old packing with a packing hook. The lantern ring in double packed
valves should also be removed with the packing hook, utilizing the holes drilled in the top of the lantern ring, which, in
the case of larger valves, are threaded. This feature permits the use of threaded rods for removal in difficult cases.
During these operations take care not to scratch the stem.
3. After the old packing is removed, inspect the stuffing box for cleanliness. Blowout with compressed air if available.
4. Install new rings one at a time. Be careful that the cut ends of the rings butt together and do not overlap. This is
particularly important when packing is cut from roll stock. Install the rings with the butt joints offset 180' from each
other. Do not use a pointed instrument to push the rings into position. A packing iron should be used for this purpose
(Fig. 8). The ability of packing to seal the stem is dependent on the amount of loading that each individual ring
receives. It is particularly important for the bottom rings in the stuffing box to be forced tightly into place. This is most
easily accomplished by ramming the rings into place with the packing iron. When packing double packing boxes with
leak-off it is essential that sufficient rings of lower packing be installed to position the lantern ring at the level of the
leak-off. When the stuffing box is full, tighten the gland nuts evenly to ensure that the gland is concentric with the
stem. Cocking of the gland or gland flange can cause binding and scoring of the stem.
5. Operate the valve once to verify that the packing is not too tight and binding the stem.
6. After the valve has been in operation a few days, retighten the packing nuts to compensate for compression of the
packing. At this time, if there is room, it is advisable to add another ring of packing.
7. Remove stem from backseated position so that packing does not dry out.
FIGURE 8
PACKING IRON