Emerson Sempell series Installation And Maintenance Instructions Manual page 4

SEMPELL HIGH PRESSURE FORGED GLOBE VALVES
INSTALLATION AND MAINTENANCE INSTRUCTIONS
Periodic valve verification during service
A - Normal checks
1. Verify every half month that there is no
leakage from packing or in the body/bonnet
area. If the leakage has been detected
from the packing, tighten the gland nuts
(Figure 4, pos. 17) slowly and evenly until the
leakage stops, as indicated in Table 1.
If the leakage has been detected from the
body/bonnet, tighten the nuts (Figure 4,
pos. 10) as indicated in Table 2.
If the leakage does not stop, it is necessary
to replace the body/bonnet gasket or to
replace the packing.
2. Every 3-6 months, depending on operating
frequency, verify the greasing of bearings
and the stem thread.
3. For actuated valves, in addition to above,
please refer also to the warnings in the
actuator manual.
B - Preventive actions
1. Every 6 months verify the tightness of gland
bolts.
2. Every 6 months on motorized valves and
every 8 months on hand operated valves,
grease the stem and the bearings.
3. Every 4 years disassemble the critical
service valves and/or actuated valves, verify
the seat surfaces and lap them again when
necessary. Replace the bonnet gasket and
the packing, clean the stem.
4. For the actuator, proceed as indicated in its
maintenance manual.
TABLE 1 - Torque (Nm) for packing bolts
Diameter Material
Metric B7/L7/B16
M8 39
M10 74
M12 127
M14 200
M16 305
M18 421
M20 588
M22 793
M24 1006
M27 1458
M30 1973
M33 2662
M36 3418
M39 4395
M42 5436
M45 6751
M48 8125
M52 10443
M56 12978
M60 16317
M64 19457
M68 23515
Adjustment of electric actuators
1. For each valve equipped with actuator,
a torque calculation has been made.
The size of the actuator is selected on the
base of the calculation.
2. The calculated torque is adjusted in the
open and close direction on the actuator.
This torque is calculated to suit the valve.
3. Before assembling an actuator to a valve,
it is necessary to check:
- The technical data of the actuator.
- The correct adjustment torque.
- The operation instruction.
4. Adjustment of the actuator for GLOBE
valves.
WARNING
In the open direction, only the stop has to be set
with the limit switch. In case the limit switch is not
adjusted, the backseat will be destroyed by the
high torque.
In the close direction, the torque switch shall
be set.
The adjustment of the limit switches has to be
handled when the actuator is assembled to the
valve according to the operation instructions.
For this reason note that:
• The calculated torque must be adjusted.
• The closing time must not be too short,
because the energy in the close blocked
position depends on the actuator speed.
• The test performed without pressure under
the piston must be avoided, because the
actuator runs with full speed into the seat
without any reaction.
TABLE 2 - Torque (Nm) for pressure seal bolts
Diameter
B8/B8M
Metric
12
M10
24
M12
40
M14
63
M16
96
M18
133
M20
186 M22
251
M24
318 M27
461
M30
623
M33
841
1080
1389
1718
2133
2568
3300
4102
5157
6149
7431
TABLE 3 - Torque (Nm) for body/yoke bolts
Diameter
Material
Metric
All
M10
30
M12
70
M14
105
M16
140
M18
200
M20
260
M22
420
M24
580
M27
760
M30
1055
M33
1350
M36
M39
M42
M45
M48
M52
M56
M60
M64
M68
Material
B7/B16
59
101
161
247
341
484
654
834
1223
1660
2250
2894
3746
4637
5789
6888
8869
11055
13711
16568
18242
4