Step Procedure
6
Check the correct mounting orientation of the packing follower in
Figure 9-1 or
Figure 9-2. Insert it, paying extra attention not to damage the surface of the stem.
7
Stack the Belleville springs as shown in
Figure 9-5, and insert them into the pack-
ing follower.
3 same-direction washers × 22 same-direction washers × 3
PTFE yarn Expanded graphite
Figure 9-5.
8 Place the packing flange onto the packing follower.
9 Apply the anti-seizure agent Never-Seez, made by Bostik, Inc., as indicated in
Table 9-3, to the threads on the gland nut end of the gland stud bolts and to the
seating end of the gland nuts, and screw the nuts on by hand.
(3) Tightening
Step Procedure
1 Tighten the left and right gland nuts alternately, making approximately a half turn each,
until the torque indicated in
Table 9-4 or Table 9-5 is reached. Note that if the tight-
ening torque is insufficient, the specified seal performance may not be achieved. On
the other hand, tightening the gland nuts with excessive torque increases the friction
on the stem and causes the gland packing (main packing and adapter packing) to wear
out faster, which may lead to an amount of leakage exceeding the specified value in a
short period of time.
Table 9-4. Gland nut tightening torque (for PTFE yarn packing)
Actuator model Stem size Tightening torque
PSA2
φ 13 mm
11 N·m
PSA3, PSA4
φ 16 mm
25 N·m
PSA6
φ 30 mm
54 N·m
Table 9-5. Gland nut tightening torque (for expanded graphite packing)
Actuator model Stem size Tightening torque
PSA2
φ 13 mm
11 → 0 (loosening) → 7 N·m
PSA3, PSA4
φ 16 mm
25 → 0 (loosening) → 17 N·m
PSA6
φ 30 mm
54 → 0 (loosening) → 36 N·m
9-5
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