The Ball Valve has an equal percentage flow characteristic and provide reliable throttling of gases and liquids within a 20-100% range.
By using throttle attachment further accurate control of fluid can be achieved.

Ball Valves are soft seated valves and if purchasers insist it can be tested 1.1 times of max. Cold working pressure. However it should be noted that soft seated ball valves tested to maximum test pressure might have a reduced performance capability in some subsequent services at low differential pressure.

Performance of Butterfly valves require precise and specific rotation limits and it often require sealing adjustment for disc 0° to 7° after installation and will experience premature seat failure if the disc is forced into seat.
0 - 90° Rotary actuator force the disc into seat and thereby causing premature failure with bi-directional over travel actuator will solve this problem, by field travel stop adjustment facilities to stop disc precisely where it should be.
As we also know all manufactured items have ± acceptable tolerances. When these tolerances of the components of automated valves are added, the actuator must provide compensation by over travel stopper. Hence over travel with travel stop actuator is required for all rotary valves including Ball and Plug valve.

Though there are no difference in physical and mechanical properties of rod and cast alloy of the same type material (CFM/.SS316), There is a variation in chemistry to provide optimum forgeability on the one hand and optimum castability on the other hand.
Though variation in chemical composition may appear small but they are not insignificant thry influence the micro structure on which the material properties depend( ferrite structure gets precipitated in casting, hence magnetic).