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667 Actuator (Size 30/30i - 76/76i and 87)
May 2018
1. If necessary, push the valve stem down so that the valve plug is touching the seat ring on direct‐acting valves. For
reverse‐acting valves, pull the stem up to the closed position. Always start with the valve plug on the seat.
2. If necessary, screw the valve stem locknuts down, away from the connector location. For all actuators except size
87, ensure that the travel indicator disk (key 34) is on top of the locknuts.
3. Adjust the diaphragm pressure to the lower bench set pressure (or, the upper bench set pressure for reverse‐acting
valves.) This should be the same pressure used in the Spring Verification steps, and it is marked on the nameplate.
4. Place the stem connector half with the threaded holes approximately half way between the actuator and valve
stems, and align the actuator stem and valve stem with threads from both stems mated root-to-crest with the stem
connector. If the threads from one of the stems do not fully align with the stem connector, a slight change to
loading pressure may be necessary to align the threads. Refer to figures 6, 7, 8, 9, and 10 to help locate the
connector position.
CAUTION
Incomplete engagement of either the valve stem or actuator stem in the stem connector can result in stripped threads or
improper operation. Be sure that the length of each stem clamped in the stem connector is equal to or greater than one
diameter of that stem. Damage to threads on either stem or in the stem connector can cause the parts to be replaced
prematurely. Do not loosen the cap screws when the stem connector has spring or loading pressure force applied.
5. Install the other half of the stem connector and insert the cap screws and tighten them while ensuring even spacing
between the stem connector halves on all sides. If installing a positioner, also attach the feedback bracket at the
same time.
CAUTION
Over‐tightening the valve stem locknuts can make disassembly difficult.
6. Screw the valve stem locknuts up against the stem connector for the size 87 actuator. For all other actuator sizes,
screw the valve stem locknuts up until the indicator disk contacts the bottom of the stem connector. Do not
overtighten the locknuts.
7. Slowly stroke the valve from fully open to fully closed and verify full rated travel is achieved.
Be sure that the valve is in the closed position. Loosen the screws on the travel indicator scale (key 32), and align it with
the travel indicator disk (key 34). Stroke the valve full travel to ensure that the travel matches the rated valve travel on
the nameplate. If valve travel is not correct, repeat the stem connector procedure.
Friction Discussion
If you are attempting to adjust the bench set after the actuator is connected to the valve and the packing tightened,
you must take friction into account. Make the spring adjustment so full actuator travel occurs at the bench set values
(a) plus the friction force divided by the effective diaphragm area with increasing diaphragm pressure or (b) minus the
friction force divided by the effective diaphragm area with decreasing diaphragm pressure.
If the stem connector assembly has been installed, the valve friction may be determined by the following procedure:
1. Install a pressure gauge in the actuator loading pressure line that connects to the actuator diaphragm casing.
Note
Steps 2 and 4 require that you read and record the pressure shown on the pressure gauge.
10
Instruction Manual
D100310X012
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