Metso GW Series, Installation Maintenance And Operating Instructions

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6 4 GV 74 en
4.2 Gland packing adjustment
In the event of a packing leakage tighten the hexagon nuts
(18) in ¼ turn steps each until the leakage is stopped. Do
not tighten more than necessary.
4.3 Replacing the 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.
Table 1 Required torques for 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.

Turn the body (1) and remove the bottom hexagon
nuts (17).

Remove the bottom flange (26).

Remove the body gasket (65).

Remove the stem (5) and plug (3) sub-assembly.
Avoid from damaging the seating and guiding line
of the plug.

Remove the each two seat rings (7 & 7a) from body
(1) and bottom flange (26) using by fabricated
wrenches to be engaged the seat ring lugs and
adapted to shock wrench.
This is threaded type, if the seat ring is extremely
resistance to removal, the application of heat or pen-
etrating oil will be helpful.

Remove the hexagon nuts (18), gland flange (9b)
and packing gland (9a) from the bonnet (8).

Remove the old packing rings (69).
CAUTION:
Do not dismantle the valve or remove it from the pipe-
line while the valve is pressurised.
Fig. 6 Gland packing
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
25 1
150-300 1/2"-13UNC 4
44 32 35 26
600 1/2"-13UNC 4
40 1.5
150-300 1/2"-13UNC 4
61 45 49 36
600 1/2"-13UNC 4
50 2
150-300 1/2"-13UNC 8 101 74 80 59
600 1/2"-13UNC 8 158 116 123 90
80 3
150-300 3/4"-10UNC 8 176 129
136 100
600 3/4"-10UNC 8 211 155
100 4
150-300 7/8"-9UNC 8 222 163
160 118
600 7/8"-9UNC 8 327 240
150 6
150-300 1"-8UNC 8 316 232
291 214
600 1"-8UNC 12 327 240
200 8
150-300 1-1/4"-8UNC 8 478 351 478 351
600 1-1/4"-8UNC 12 653 479 653 479
250 10
150-300 1-1/4"-8UNC 12 486 356 486 356
600 1-1/4"-8UNC 16 909 667 716 525
Fig. 7 Tightening sequence of the bonnet nuts
NOTE:
The trim set consists of the seat rings, valve plug and stem,
gaskets (for body).
CAUTION:
If using heating devices, insure that proper safety
practices are observed. Such items as the flammability
and toxicity of the controlled substance must be consi-
dered and proper precautions and permissions taken.