TOV
Installation, Operation and Maintenance Manual
18
WKM-TOV-IOM
Mounting Operators To
WKM TOV’s
1. Before mounting the operator, the valve position shall be verified for open and close by using the dimple feature
provided on the stem as mentioned on page 9.
2. WK
M TOV’s are torque seated in the closed position and are position seated in the open position, therefore to
achieve valve shut off, a few degrees over travel may be required in the operator. Travel stops shall be adjusted
accordingly.
3. Mounting bracket shall be sufficiently rigid to support operator weights and weight imbalances. Stacking mounting
brackets over one another shall be avoided.
4. Parallelism between the top and bottom surfaces of mounting bracket and the flatness of each of these surfaces
shall be maintained to close tolerances. A maximum deviation of 0.2mm is recommended for Parallelism as well
as for Flatness independently.
5. Mounting bracket bolt holes of the top and the bottom surfaces shall be aligned precisely with each other as well
as with the corresponding bolt holes of the actuator and the valve.
6. Adapters for the valve stem/ operator interface shall be designed and manufactured to prevent eccentricity which
can cause misalignment and possible side loads.
7. For scotch yoke type operators, sizing shall be performed such that the run torque is greater than at least 50% of
the published valve break to open torque.
8. Mounting brackets shall be designed to accommodate for the dowel pins on the valve top flange. For the bracket/
operator interface, it is recommended to secure the alignment by using a dowel pin or a spigot mechanism.