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11. Actuation
Type 87/88 Multi-Spring Diaphragm
Actuators
Connecting Type 87 (Air to Extend) No. 6 Actuator (Figure 23)
1. Tightly assemble the hex nuts (1) onto the plug stem.
2. Push down the actuator, and screw on the yoke nut (33) at
the same time. Then assemble the bottom stem connector
(2). As soon as it becomes possible, insert the valve stem
into the actuator stem (10).The stem must be inserted far
enough so that when there is no air in the actuator, the valve
plug does not touch the seat.
3. Tighten the yoke nut (33).
4. Supply air to the actuator at the final pressure.
5. Use the pointer (7) to set the travel scale (9) to the valve
open position.
6. Supply the actuator with air at a sufficiently high pressure to
obtain a travel equal to the nominal travel of the valve.
7. Unscrew the plug stem until the valve plug is in contact with
the seat. Do not turn the valve plug on the seat as this could
damage the sealing surfaces.
8. Screw the hex nuts (1) as far as they will go and check that
operation is correct.
Connecting Type 88 (Air to Retract) No. 6 Actuator (Figure 23)
1. Tightly assemble the hex nuts (1) onto the plug stem.
2. Push down the actuator, and screw on the yoke nut (33) at
the same time. Then assemble the bottom stem connector
(2). As soon as it becomes possible, insert the valve stem
into the actuator stem (10).The stem must be inserted far
enough so that when there is no air in the actuator, the valve
plug does not touch the seat.
3. Tighten the yoke nut (33).
4. Unscrew the valve plug stem until the valve plug comes into
contact with the seat. Do not turn the valve plug on the seat
as this could damage the sealing surfaces.
5. Supply air to the actuator until the stem has travelled at least
.40 inches (10 mm).
6. Unscrew the plug stem by the number of turns N1 specified
in Table 5.
7. Screw the hex nuts (1) as far as they will go and check that
operation is correct.
8. Use the pointer (7) to set the travel scale (9) to the valve
closed position.
Plug Stem
Diameter
N1 (turn)
in
mm
1”
1.25
0.09
2.3
3/4”
1.25
0.08
2.0
5/8"
1.5
0.08
2.0
1/2”
1.5
0.075
1.9
Table 5 - Type 88 Actuator, Air to Open - Valve Seating
Connecting Type 87 (Air to Extend) No. 10, 16 and 23
Actuators (Figure 23)
1. Tightly assemble hex nut (1) onto the plug stem.
2. Screw the top stem connector (4) assembly tightly onto the
actuator stem (10).
3. Push down the actuator, and screw on the yoke nut (33) at
the same time. Then assemble the bottom stem connector
(2) assembly by screwing until it comes into contact with the
hex nut (1).
4. Push down the actuator and tighten the yoke nut (33).
5. Supply the actuator with air at the initial pressure indicated
on the spring scale.
6. Position the stem connector assembly at distance “X”
indicated in Table 6.
7. Use the pointer (7) to set the travel scale (9) to the valve
open position.
8. Supply the actuator with air at a high enough pressure to
obtain a travel equal to the nominal travel of the valve.
9. With the plug correctly positioned on the seat, unscrew
the bottom stem connector (2) assembly until it comes into
contact with the top stem connector (4). Tighten the socket
head cap screws (5), hex nut (1) and lock nut (32) and
check that the operation is correct.
