8
5 FT 70 en
4.3.2
FL series
In gland packings, tightness is ensured by the contact
between the gland follower and the packing rings. See Fig. 14.
The gland packing (20) must be replaced if leakage occurs
even after the hexagon nuts (25) have been tightened.
Make sure that the valve is not pressurized.
Detach the actuator and bracket according to the
instructions in Section 4.4.
Remove the key (13).
Remove the hexagon nuts (25), disc spring sets (32),
one stud (24), retaining plates (30) and gland fol-
lower (9).
Remove the packing rings (20) from around the shaft
using a knife or some other pointed instrument
without scratching the surfaces.
Clean the packing ring counterbore.
Place the new packing rings (20) over the shaft (11).
The gland follower may be used for pushing the
rings into the counterbore. Do not damage packing
rings in the shaft keyway. See Fig. 14.
Screw down the removed stud.
Deform the packing rings first by tightening the
gland nuts (25) without disc springs to the torque Tt,
see the value from Table 3.
Remove the gland nuts and one stud. Mount the
retaining plates (30) with the text UPSIDE on top, see
Fig. 15, and the removed stud and place the disc
spring sets (32) on the gland studs. Tighten the nuts
(25) so that the disc springs are compressed to the
height Hc, see Table 3. Lock the nuts with locking
compound e.g. Loctite 221.
Insert the key (13) in the drive shaft (11) keyway.
Re-install the actuator.
Check leakage when the valve is pressurized.
4.4
Detaching the actuator
It is generally most convenient to detach the actuator and
its auxiliary devices before removing the valve from the
pipeline. If the valve package is small or if it is difficult to
access, it may be more practical to remove the entire pack-
age at the same time.
See Section 6 for details of detaching actuators.
4.5
Removing the valve from the pipeline
After you have detached the actuator as described above,
unscrew the pipe flange bolts. If necessary, support the
valve to prevent it from falling, for instance, with hoisting
ropes. Turn the valve so that no medium is left inside.
Table 2
Tightening of the gland packing
Valve size
Shaft
dia
Spring
dimensions
(free)
PTFEV-ring
Graphite
Disc
spring
Nut
Disc
spring
Nut
DN
NPS
mm
A, mm H,mm
He,m
m
Tt,Nm
He,m
m
Tt,Nm
25
1
15
20
22
21
3
202
6
40
15
15
20
22
21
3
202
6
50
2
20
20
22
21
3
202
6
80
3
25
25
233
222
8
219
14
100
4
35
315
352
344
20
32
34
150
6
35
315
352
344
20
32
34
200
8
45
40
455
443
35
415
70
250
10
45
40
455
443
36
415
70
Fig. 14
Gland packing, FL
A
Hc
24
30
32
9
20
25
13
CAUTION:
For safety reasons the retainer plates MUST always be
installed according to the above instructions.
Fig. 15
Installing the retainer plates
Table 3
Tightening of the gland packing
A (mm)
Hc (mm)
Tt (Nm)
20
20.4
5
CAUTION:
When handling the valve or the valve package, bear in
mind its weight!
NOTE:
Before dismantling, carefully observe the position of the
valve with respect to the actuator and positioner/limit
switch so as to make sure that the package can be prop-
erly re-assembled.
CAUTION:
Do not dismantle the valve or remove it from the pipe-
line while the valve is pressurized!
