Stroking Range; Maintenance - Emerson Fisher 1052 Instruction Manual

1052 Size 20 Actuator (F & G)
February 2019
Proper bench set of the spring can only be made when the actuator "up" travel stop has been approximately adjusted.
Insert a shaft in the actuator and adjust the "up" travel stop before establishing spring compression (since there is no
travel stop in the upper diaphragm casing). Considerable error in adjustment is certain if the above procedure is not
followed. This error can result in under travel of the actuator when the spring goes solid or excess spring compression
has been applied.
Adjust the spring so that the diaphragm rod just starts to travel at the Spring Initial Set pressure specified on the
nameplate. To adjust the spring, remove the positioner, if one is used, or the cover. The lower part of the spring
adjusting screw is notched, as shown in figure 3. Using a screwdriver as shown in figure 3, rotate the notches to the
right to decrease spring compression or to the left to increase spring compression. Replace the positioner or the cover.

Stroking Range

If, under operating conditions, the stroking range does not match the intended casing pressure, it may be possible to
shift the stroking range by making a spring adjustment to change the initial spring compression. A spring adjustment
will shift the casing pressure span and will equally increase (or decrease) the casing pressure at which the actuator
begins to stroke and the pressure at which the actuator reaches full travel.
To adjust the spring, remove the positioner, if one is used, or the cover. The lower part of the spring adjusting screw is
notched. Using a screwdriver as shown in figure 3, rotate the notches to the right to shift the casing pressure span
downward, or to the left to shift the casing pressure span upward. Replace the positioner or the cover.

Maintenance

Actuator parts are subject to normal wear and must be inspected and replaced as necessary. The frequency of
inspection and replacement depends upon the severity of service conditions. Instructions are given below for
disassembly and assembly of parts. Key numbers are shown in figure 5, unless otherwise noted.
WARNING
Avoid personal injury or property damage from sudden release of process pressure or uncontrolled movement of parts.
Before performing any maintenance operations:
D Always wear protective gloves, clothing, and eyewear when performing any maintenance operations to avoid personal
injury.
D Disconnect any operating lines providing air pressure, electric power, or a control signal to the actuator. Be sure the
actuator cannot suddenly open or close the valve.
D Use bypass valves or completely shut off the process to isolate the valve from process pressure. Relieve process pressure
from both sides of the valve. Drain the process media from both sides of the valve.
D Vent the power actuator loading pressure and relieve any actuator spring precompression.
D Use lock‐out procedures to be sure that the above measures stay in effect while you are working on the equipment.
D The valve packing box may contain process fluids that are pressurized, even when the valve has been removed from the
pipeline. Process fluids may spray out under pressure when removing the packing hardware or packing rings, or when
loosening the packing box pipe plug.
D Check with your process or safety engineer for any additional measures that must be taken to protect against process
media.
6
Instruction Manual
D100322X012