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Valve size
ASME
(in)
class
2
150, 300 or 600
3
2500
2
900 or 2500
3 and 4
150 to 1500
4 and 6
2500
6
150 to 1500
8
2500
8
150 to 1500
10
2500
10, 12 and 16
150 to 1500
12 and 16
2500
18
150 to 1500
A = Pilot plug travel
Figure 14. Seating value for 41405 valves
7.5
Coupling of Air-to-Extend Actuator
(Type 37)
(Figure 16)
A. Push down on the plug stem (1) until the plug rests
is seated.
B. Attach the actuator to the valve bonnet with the
yoke nut (33) or attachment screws. Apply a sufficient
pressure to the diaphragm to extend the actuator
stem by the normal valve travel for valves 41305,
41505, 41605 and 41905 and the travel minus the
value of A in Figure 14 for 41405 valves.
C. Assemble the two parts of the stem connector (51)
and the point (58). The number of threads inside the
stem connection must be approximately equal for
each stem. Tighten screw(s) (52).
D. Check that the travel of the actuator stem
corresponds to the normal travel of the valve and
that the closed position is obtained for the maximum
spring range indicated on the serial plate.
E.
Shut off the air pressure. Use the pointer (58) to set
the travel scale (56). The pointer (58) must indicate
"open" when the air pressure is off.
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Value A
Value a1
mm (in)
mm (in)
2.5 (0.1)
4.4 (0.17)
2 (0.08)
3.9 (0.15)
3 (0.12)
5 (0.2)
5 (0.2)
7 (0.27)
6 (0.24)
8.3 (0.33)
7 (0.275)
9.3 (0.37)
7.6
Coupling of Air-to-Retract Actuator
(Type 38)
(Figure 16)
A. Connect a temporary air supply line to the actuator.
Apply sufficient pressure to the diaphragm to
retract the actuator stem completely. Attach the
actuator to the valve bonnet with the yoke nut (33)
or attachment screws.
B. Shut off the air pressure completely. Increase the air
pressure to retract the actuator stem by the value of
a in Figure 13.
For 41405 valves, use value a1 of Figure 14.
C. Assemble the two stem connectors (51) and the
pointer (58). The number of threads inside the stem
connection must be approximately equal for each
stem. Tighten screw(s) (52).
D. Check that the travel of the actuator stem
corresponds to the effective travel of the valve and
that the closed position is obtained for the minimum
spring range indicated on the serial plate.
E.
Shut off the air pressure then use the pointer (58)
to set the travel scale (56). The pointer (58) must
indicate "closed" when the air pressure is nil.
7.7
Other Types of Pneumatic Actuators
For other type of actuators which the coupling valve
actuator is realized by coupling parts (see Figure 16)
follow the procedure:
• § 7.5. for actuator opens by air failure.
• § 7.6. for actuator closes by air failure.
Masoneilan 41005 Series Globe Valve Instruction Manual | 19
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