7
6
12
10
2
9
20
21
5
8
14
16
4
13
1
3
11
19
17
18
15
KEYSTONE
FIGURE 952 KNIFE GATE VALVES
INSTALLATION AND OPERATING MANUAL
© 2017 Emerson. All Rights Reserved.
Gland packing replacement instructions for DN 50 - 200 (NPS 2 - 8)
Figure 952 knife gate valves
PACKING REPLACEMENT
For optimum performance, the packing
material should be replaced whenever the
valve has been disassembled for routine
maintenance. This is a very simple procedure
which can be done leaving the valve in the
pipeline.
Correct packing is essential for leak-free
operation. Use Emerson’s preformed and pre-
cut packing replacement kits for best results.
Kits are available in the following types:
K-LON
- Standard packing material.
D-LON
- Food grade packing.
G-LON
- High cyclic packing.
H-LON
- Abrasive service packing.
Ensure packing material selected is suitable
for the service.
DISASSEMBLY PROCEDURE
1. Ensure the pipeline is not pressurized and
any hazardous medium is drained away.
2. Close valve. Loosen gland box nuts (10)
to end of pillar (9) threads.
3. Remove clevis fastener (19).
4. Remove both bridge bolts (14).
5. Remove bridge sub-assembly (handwheel,
handwheel nut, spindle and bridge or
cylinder actuator and bridge).
NOTE
Heavy valves will require a chain block or crane to
assist.
6. Unscrew both pillars (9).
7. Unscrew gate guides approximately 2 turns
(Not applicable on polyurethane trim valves).
8. Withdraw gland box (3) and gate (2)
sub-assembly.
9. Remove scraper (7) (Not fitted on
polyurethane trim valves) and packing
segments (6) from the gland box (3), noting
the number of layers.
10. Clean gland box (3) and gate (2). Check gate
for irregularities or abrasion on the seating
side. If excessive, discard and replace.
Note:
DN 50 - 200 (NPS 2 - 8) valve illustrated.
Emerson.com/FinalControl
VCIOM-02046-EN 18/07
PACKING PROCEDURE
NOTE
Care should be taken to stagger the mitred joints
in each layer of packing to the opposite side of the
gland box, e.g.;
• 1st packing layer joint to the front of the valve
• 2nd packing layer joint to the rear of the valve
• (on larger valves) 3rd packing layer joint to the front
of the valve.
1. Press first layer of gland packing (6) into
gland box (3) cavity by hand, then repeat
the process with the second layer ensuring
the joints of the two layers are on opposing
sides of the cavity
2. Push gate (2) (rounded edge first) gently
through top of gland box with packing
underneath, then turn upside down and
push gland box to 25 mm (1") from the
end of the gate. Firmly press packing in
with fingers around gate then fit the RTFE
scraper blade (7) (Not fitted on polyurethane
trim valves) in bottom of gland box.
