Ball valves are widely recognized as one of the most prevalent types of valves, characterized by their quarter-turn operation and a perforated ball positioned at the center to regulate fluid flow. While acknowledged for their robustness and effective shut-off capabilities, ball valves may not always offer precise flow control. The decision to employ a ball valve as a control valve depends on specific application requirements.

Despite their limitations in providing highly accurate control, control ball valves remain popular due to their cost-effectiveness. They are suitable for applications where precise adjustability and control are not critical. For instance, maintaining a specific liquid level in a large tank with a few inches of tolerance can be effectively accomplished using a ball valve.

Ball Valves

Selecting the appropriate valve involves considering various factors such as material compatibility, piping size, flow rate, and operating conditions. When dealing with valuable substances that are not to be wasted, alternative valve types may be preferred over a ball valve.

The inherent lack of precision in ball valves arises from the disproportionate adjustment in relation to the substantial flow facilitated by the fully open position. Additionally, the presence of 'slop' or 'play' between the stem and ball introduces variability, preventing precise control. The torque required for adjusting ball valves limits fine-tuning near the "shut" and "open" positions.

For applications demanding precise control, globe valves are recommended over ball valves. Globe valves are regarded as the industry standard for control valves due to their capability to regulate flow efficiently, whereas ball valves excel in on/off control scenarios with minimal pressure drop.

In instances where a ball valve is deemed necessary for control purposes, consideration of alternative designs may enhance performance. Trunnion or v-port ball valves, for example, offer improved precision in specific situations. Trunnion ball valves feature additional mechanical anchoring at the top and bottom of the ball, eliminating play between the ball and stem through a splined or keyed stem connection. V-port ball valves, on the other hand, incorporate a 'V' shaped ball, allowing for enhanced control with a tapered opening for more direct flow.