I
MO-D52/R52
3
9/21 Rev. 0
Description
Direct Acting Actuator
Model D52 actuators are linear-motion spring-return pneumatic diaphragm actuators, primarily intended for
use with rising stem type valves. In the “normal” position (no air pressure on the diaphragm), the direct
actuator holds the stem in its retracted position by means of a mechanical spring. Increasing air pressure
in the upper diaphragm chamber thrusts the actuator stem downward and compresses the spring.
Mounted on pull-stem-to-open valve body assemblies, the direct actuator closes the valve when increasing
air pressure is applied to the upper diaphragm chamber. Mounted on push-stem-to-open valve body
assemblies, the direct actuator opens the valve when increasing air pressure is applied to the upper
diaphragm chamber. An external spring adjustment permits the spring compression to be changed within
predetermined limits. These actuators are manufactured for and applied to meet the requirements of the
valve and the service conditions as specified in the sales order and are ordinarily shipped mounted on the
valve body subassembly and with all accessory equipment mounted, piped, and adjusted.
Reverse Acting Actuator
Model R52 actuators are linear-motion spring-return pneumatic diaphragm actuators, primarily intended for
use with rising stem type valves. In the “normal” position (no air pressure on the diaphragm), the reverse
actuator holds the stem in its extended position by means of a mechanical spring. Increasing air pressure
in the lower diaphragm chamber thrusts the actuator stem upward and compresses the spring.
Mounted on pull-stem-to-open valve body assemblies, the reverse actuator opens the valve when increasing
air pressure is applied to the lower diaphragm chamber. Mounted on push-stem-to-open valve body
assemblies, the reverse actuator closes the valve when increasing air pressure is applied to the lower
diaphragm chamber. An external spring adjustment permits the spring compression to be changed within
predetermined limits. These actuators are manufactured for and applied to meet the requirements of the
valve and the service conditions as specified in the sales order and are ordinarily shipped mounted on the
valve body subassembly and with all accessory equipment mounted, piped, and adjusted.
Receiving and transportation
This actuator is heavy and therefore needs to be handled carefully and properly, following the
instructions given below. Failure to observe these instructions may cause serious injuries.
•
For hoisting up and down the package containing this actuator, use a suitable hoisting machine
conforming to the Occupational Health and Safety Law. Do not allow any person to be beneath
the package being hoisted up, nor operate the hoisting machine beneath the package being
hoisted up.
•
Storage
(1)
It is recommended that the actuator is stored in an as-received packed state before
installation.
(2)
Do not store it in a place:
a.
Exposed to rainwater.
b.
Where ambient temperature is higher than 140°F (60°C)
c.
In a dusty environment
d.
In a humid atmosphere
(3)
Even when the received actuator has been unpacked for acceptance inspection, it is
recommended that the actuator is repacked as received and stored.
(4)
Do not remove the plugs or covers of the wiring port until wiring work is started.
(5)
To store the actuator after use, treat it as follows.
a.
Apply rust preventive treatment to the parts that are liable to rust.
b.
Insert plugs or other waterproof treatment to the air-pipe connecting ports and the wiring ports.
