Instruction Manual
D100306X012
657 Actuator (30/30i-70/70i and 87)
June 2018
7
CAUTION
Stroke the actuator a few times to ensure that the pressure gauge is working correctly, and that the actuator is functioning
properly. To prevent actuator damage, it is important to ensure that the actuator stem is stroking smoothly and not
exhibiting binding or excessive friction. Binding or excessive friction could be an indicator of incorrect assembly or
damaged parts.
1. If not already accomplished, provide a temporary means of applying an adjustable loading pressure to the actuator
during bench set adjustments.
2. Set the diaphragm loading pressure at 0 bar (0 psig). Then, slowly raise the pressure towards the lower bench set
pressure, as indicated on the nameplate, while checking for the first linear movement of the actuator stem. The
actuator stem should show movement at the lower bench set pressure. If movement occurs before or after the
lower pressure is reached, adjust the spring adjuster (see figure 4) into or out of the yoke until the actuator stem's
movement is first detected at the lower bench set pressure.
Note
Before turning the spring adjuster on size 70/70i or 87 actuators, assemble the stem connector around the actuator stem and the
anti‐rotating lug on the yoke. Mark the actuator stem as a visual reference to verify that stem rotation does not occur. Remove the
stem connector before rechecking the bench set.
3. Be sure the spring adjuster is adjusted to meet the requirements of step 2 above.
4. Apply the upper bench set pressure, as indicated on the nameplate. This pressure extends the actuator stem down
towards the valve. At the end of the actuator stem, use a marker or a piece of tape to mark the valve stem (see
figure 4).
Note
The actuator stem may slide over the valve stem as shown in figure 4. If the actuator stem does not pass over the valve stem,
provide a method to mark this point of stem travel.
5. Slowly decrease the diaphragm loading pressure to the lower bench set pressure, as indicated on the nameplate.
6. Measure the distance between the marker or tape on the valve stem to the end of the actuator stem. The distance
should match the rated travel indicated on the nameplate.
7. If the measured travel matches the nameplate travel, bench set is complete. Proceed to the Installing the Stem
Connector Assembly subsection.
8. If the measured travel is not exact, consider the spring free-length and spring rate tolerances may produce a slightly
different bench set than specified. Contact your
or Local Business Partner for assistance.
Installing the Stem Connector Assembly
When installing the stem connector assembly (key 26), the actuator and valve stem threads should engage the
threads of the stem connector by the distance equal to the diameter of the stem.
