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667NS2 Actuator
March 2022
Principle of Operation
The 667NS2 actuator positions the valve plug in response to varying pneumatic loading pressure on the actuator
diaphragm. Figure 2 shows the operation of these actuators. The actuator stem moves up as the loading pressure is
increased on the bottom of the diaphragm. As the loading pressure is decreased, the spring forces the actuator stem
down.
The spring and diaphragm have been selected to meet the requirement of the application and, in service, the actuator
should produce full travel of the valve with the diaphragm pressure as indicated on the nameplate.
A side-mounted handwheel assembly is available on this actuator, used as an auxiliary manual actuator. The manual
operator is normally in a neutral position, allowing the actuator to function normally as if the manual operator was not
on the actuator. When the handwheel is rotated counterclockwise, a geared sleeve moves up and contacts a collar on
the actuator shaft. Continued rotation of the handwheel will move the actuator and valve stem to the up position.
Rotating the handwheel clockwise will move the geared sleeve down, and will contact the valve-actuator stem
connector. This will prevent upward movement of the plug/stem of the valve. By rotating the handwheel to a position
between neutral and either full open or full closed, the side-mounted handwheel can be used as an adjustable up or
down travel stop.
Lifting Guidelines
WARNING
Failure to follow these lifting guidelines and accepted lifting and rigging practices could result in property damage and
personal injury or death.
All lifting and rigging must be completed in accordance with federal/national/provincial, state and local regulations and
applicable lifting and rigging equipment standards. Only personnel trained in proper lifting and rigging practices shall
perform valve/actuator assembly lifting, rigging and installation. Because each lift will be unique, the method of lifting the
valve assembly, the correct location for attaching and lifting the valve assembly, and what the valve assembly will do when
lifted shall be considered for each lift.
Lifting and rigging equipment used to lift, install or remove a valve assembly or component must be properly selected and
sized for the weight and configuration of the valve assembly or component being lifted. The weight of the complete valve
assembly, including attached accessories, must be taken in consideration for this purpose. The lifting and rigging
equipment must be properly maintained and inspected for damage before each use.
If the valve is supplied with an actuator or handwheel, do not use the actuator or handwheel to lift the complete valve
assembly. Lifting lugs attached to the actuator must not be used to lift the complete valve assembly unless clearly marked
as being rated to support the complete valve assembly weight.
Lifting lugs or other lifting equipment attached to the valve or actuator must never be used to lift or support the weight of
attached piping.
CAUTION
Care must be taken when lifting the valve/actuator assembly to ensure all accessories and tubing are not damaged in the
process. Accessories and tubing may need to be removed prior to lifting to prevent damage and properly reinstalled before
use. Protect valve flange faces, butt weld ends, and other connection surfaces from damage during lifting.
The quantity of eyebolts for lifting purpose is the minimum recommendation. More eyebolts can be used per customer
experience. When tightening the eyebolts and nuts, do not exceed the torque that is specified on the diaphragm casing cap
screws and nuts (keys 119 and 120) in the following sections, to avoid damage on the diaphragm.
4
Instruction Manual
D103472X012
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