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667NS2 Actuator
March 2022
WARNING
If the control valve and actuator are installed with the actuator in any position other than vertical, the actuator may not
conform with safety‐related qualifications. Nonvertical orientation should be part of existing qualification analysis on file at
the plant site to ensure conformance with safety‐related qualifications. Certain nonvertical orientations can cause water to
collect in the yoke and actuator spring areas, eventually causing degradation in product performance.
Note
The 667NS2 actuator is intended to mount directly to HPNS valve bodies, as in the cases of valve sizes NPS 1 through NPS 6. On the
NPS 1/2, however, the actuator mounts to the yoke spacer (figure 5) which mounts to the valve body. On the NPS 8 valves, the
actuator mounts directly to the bonnet.
If the actuator and control valve body are separate, mount the standard 667NS2 actuator, or 667NS2 actuator with
side-mounted handwheel, by following the procedures in the Mounting the Actuator on the Valve section of this
manual.
Mounting the Actuator on the Valve
CAUTION
The 667 actuator spring load pushes the stem down out of the actuator yoke, and it can come in contact with the valve
stem during actuator mounting. If the valve stem is allowed to remain in the up position (towards the actuator) during
actuator mounting, it can interfere with the actuator stem during mounting. It is possible to damage valve stem threads or
bend the valve stem. Be sure the valve stem is pushed down (into the valve body), away from the actuator while mounting.
It may be necessary to apply a temporary loading pressure to the actuator to move the actuator stem away from the
valve during installation.
If it is not possible to provide a temporary loading pressure, be very careful when lowering the actuator over the valve
stem to prevent damage to valve stem and threads.
WARNING
When moving the actuator stem with loading pressure applied, exercise caution to keep hands and tools out of the
actuator stem travel path. If the loading pressure is accidentally disconnected, personal injury and property damage may
result if something is caught between the actuator stem and other control valve parts.
Refer to figure 2. The steps below apply to standard 667NS2 actuator and 667NS2 actuator with sidemounted
handwheel.
1. Provide a vise or some other method of supporting the valve and the weight of the actuator during assembly. Push
the valve stem down away from the actuator while mounting the actuator.
2. Thread the stem locknuts (key 115) all the way onto the valve stem.
3. Coat the threads of the actuator mounting studs (key 101) with Nuclear Grade anti-seize lubricant (key 27) up to
the deformed thread. Thread the actuator mounting studs (key 101) into the valve body until the deformed thread
prevents further insertion.
Note
For actuators with yoke spacers (key 209) ( when lifting the actuator and yoke spacer together) follow previous instructions for
lifting the entire valve/actuator assembly.
6
Instruction Manual
D103472X012
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