6
4 GV 76 en
4.3
Replacing the gland packing
Fig. 6
Gland packing
Make sure the valve is not pressurised.
Remove the actuator from the valve stem according
to the instructions given in the actuator manual.
Loosen and remove the hexagon nuts (18).
Remove the gland flange (9b), and gland (9a) up to
the valve stem.
Remove the old packing rings (69) using a pointed
tool, avoid damaging the seal surfaces and valve stem.
Clean the packing ring counterbore.
Mount the new packing rings one by one into the
packing gland box using the gland as a tool and
mount the gland with hand-tightened nuts.
Fasten the gland with the hexagon nuts (18) and
tighten them.
Check leakage when the valve is pressurised.
Fig. 7
Tightening sequence of the bonnet nuts
4.4
Replacing the trim and body
reassembly
Make sure the valve is not pressurised.
Remove the actuator from the valve stem according
to the instructions given in the actuator manual and
next Section 6.
Remove the hexagon nuts (18) slightly.
Remove the hexagon nuts (17).
Remove the bonnet (8)
Remove the cage guide (16), cage (15) and the seal
ring (64). Avoid from damaging the seal ring
between the cage and cage guide.
Remove the body gasket (65 & 65a), one piece of
seat ring (7) and diffuser (81), seat gasket (63).
Remove the hexagon nuts (18), gland flange (9b)
and gland (9a).
Remove the old packing rings (69).
CAUTION:
Do not dismantle the valve or remove it from the pipe-
line while the valve is pressurised!
NOTE:
The trim set consists of the seat ring, valve plug and stem,
retainer and gaskets(for seat ring and bonnet).
Standard construction
Low Emission with
Live Load Spring
Table 1
Required torques for bonnet nuts
Valve Size
Rating
(ANSI)
Bonnet Stud Bolts
Required Torques
(± 5 % allowable)
mm
in
Size
Q`ty
Carbon Steel
Bolts
St. Steel Bolts
Nm
lbf ft
Nm
lbf ft
50
2
150-300
1/2"-13UNC
8
101
74
80
59
600
1/2"-13UNC
8
158
116
123
90
900
7/8"-9UNC
8
199
146
199
146
1500
7/8"-9UNC
8
286
210
80
3
150-300
3/4"-10UNC
8
176
129
136
100
600
3/4"-10UNC
8
211
155
900
1-1/8"-8UNC
8
558
409
1500
1-1/8"-8UNC
8
792
581
100
4
150-300
7/8"-9UNC
8
222
163
160
118
600
7/8"-9UNC
8
327
240
900
1-1/4"-8UNC
8
867
633
1500
1-1/4"-8UNC
8
1339
982
150
6
150-300
1"-8UNC
8
316
232
291
214
600
1"-8UNC
12
327
240
900
1-1/2"-8UNC
12
1192
874
942
691
1500
1-1/2"-8UNC
12
1456
1068
200
8
150-300
1-1/4"-8UNC
8
478
351
478
351
600
1-1/4"-8UNC
12
653
479
653
479
900
1-5/8"-8UNC
12
1676
1229
1140
836
1500
1-5/8"-8UNC
12
1870
1372
250
10
150-300
1-1/4"-8UNC
12
486
356
486
356
600
1-1/4"-8UNC
16
909
667
716
525
900
1-3/4"-8UNC
12
2059
1510
300
12
150-300
1-1/2"-8UNC
12
729
535
729
535
600
1-1/2"-8UNC
12
1317
966
900
1-1/2"-8UNC
16
1408
1032
350
14
150-300
1-1/2"-8UNC
12
875
642
875
642
600
1-1/2"-8UNC
12
1581
1160
900
1-1/2"-8UNC
16
1689
1238
400
16
150-300
1-1/2"-8UNC
12
1529
1121
980
719
600
1-1/2"-8UNC
16
1426
1046
500
20
150-300
1-3/4"-8UNC
20
1816
1332
1725
1265
600
1-3/4"-8UNC
24
2107
1545
2001
1468
600
24
150-300
1-3/4"-8UNC
20
1923
1410
2491
1827
600
1-3/4"-8UNC
24
2216
1625
2105
1544
NOTE:
The standard is ‘quick change seat type’, other design has
a ‘weld seat type’ according to weld seat ring on the body
side.
NOTE:
The standard is one piece with seat ring (7) and the
diffuser (81) by welded, other design has a separated type
according to weld diffuser on the body side.
NOTE:
If the valve have excess leakage, the plug and seating
surface need lapping and cleaning.
NOTE:
‘Omega’ Disk Stack Cage Cleaning
The welded ‘Omega’ disk stack cage is not available
disassembling, make sure the ultrasonic cleaning in the
frequency range of 250 ~ 400 kHz and Min. duration
60 min.
