Segment ball valve

Designed for industrial fluid pipeline systems, the segment ball valve executes 90-degree rotational movement to adjust flow passage area, delivering inherent equal-percentage flow characteristics. It is renowned for high flow capacity, excellent rangeability, and unique shear cutting capability, making it a preferred solution for complex working conditions involving viscous, fibrous, granular, and slurry media . Combining the structural simplicity and low fluid resistance of ball valves with the accurate modulating performance of control valves, it serves dual purposes of flow regulation and pipeline cut-off in automated industrial process systems .

The segment ball valve features a compact, robust, and simplified internal structure with fewer vulnerable parts, effectively reducing failure points and maintenance costs. Its core components are detailed as follows:

Valve Body: Most industrial-grade segment ball valves adopt an integral one-piece casting structure, with high overall rigidity to resist pipeline pressure fluctuations, vibration, and external mechanical loads. This integrated design eliminates the leakage risks associated with two-piece split valve bodies, ensuring long-term structural stability. Common body materials include cast iron, carbon steel (WCB), and stainless steel (SS304/SS316), covering low, medium, and high-pressure working scenarios .

V-Notch Segment Ball Core: The core functional component. The specially contoured V-shaped notch on the semi-spherical ball is precision-machined with sharp cutting edges. The geometric profile of the V-notch is optimized to balance flow capacity, control accuracy, and shear performance, enabling linear and stable flow adjustment throughout the full stroke .

Valve Seat & Sealing Assembly: Equipped with high-precision hard or soft sealing pairs. Soft seals (PTFE, RPTFE, PEEK) provide bubble-tight shutoff for clean and weakly corrosive media, while hard seals (stellite alloy surfacing, stainless steel hard sealing) adapt to high-temperature, high-pressure, and abrasive media. Multiple sealing structures are applied between the valve body, ball core, and valve stem to prevent internal and external leakage .

Valve Stem & Transmission Mechanism: The high-strength valve stem features an anti-blowout design to avoid medium leakage caused by stem displacement under pressure. The optimized transmission structure ensures synchronous and stable rotation of the ball core without jitter or stuck phenomena during operation.

Actuator: Compatible with manual, pneumatic, electric, and hydraulic actuators. Pneumatic actuators are the most widely used in industrial automation due to their safety, explosion-proof performance, and low cost, while electric actuators are suitable for precise remote intelligent control .

Fireproof & Anti-static Structure: Standard industrial segment ball valves are equipped with fireproof sealing grooves and anti-static devices. When soft seals are burned out by high-temperature fire, the hard sealing structure can automatically form a secondary seal to prevent medium leakage, meeting international fire safety standards .
 

The working mechanism of the segment ball valve relies on the 90-degree quarter-turn rotation of the V-notch segment ball core. When the valve is fully open, the V-notch passage is completely aligned with the pipeline, forming a smooth and straight flow channel with minimal fluid resistance and maximum flow capacity. During the rotating process from fully open to fully closed, the overlapping area between the V-notch and the pipeline passage decreases continuously and uniformly. Thanks to the unique geometric design of the V-notch, the valve presents a standard equal-percentage flow characteristic, which means the flow change rate is proportional to the stroke change rate, realizing ultra-precise continuous adjustment of fluid flow, pressure, and liquid level .
 

In addition to flow regulation, the sharp edge of the V-notch ball core produces a powerful shear effect during rotation. When handling media containing fibers, sundries, or granular impurities, the cutting edge can instantly shear and cut off entangled fibers and large particles, avoiding blockage between the ball core and valve seat. When fully closed, the close fit between the segment ball and the valve seat achieves excellent tight shutoff performance, effectively cutting off fluid flow . It is worth noting that most segment ball valves are unidirectional sealing valves, and the installation direction must strictly follow the medium flow direction marked on the valve body to ensure optimal sealing and control performance .
 

Manual Segment Ball Valve: Equipped with handwheel or handle, suitable for manual on-off and simple adjustment of small-diameter pipelines, widely used in non-automated auxiliary pipeline systems.

Pneumatic Segment Ball Valve: Driven by pneumatic actuator, with fast response, explosion-proof safety, and low energy consumption. It is the most mainstream type in industrial automatic control systems, suitable for most process pipeline working conditions .

Electric Segment Ball Valve: Driven by electric actuator, supporting precise stroke positioning and remote intelligent control, suitable for working conditions requiring high control accuracy and centralized system management.

Hydraulic Segment Ball Valve: Driven by hydraulic pressure, with large output torque, suitable for large-diameter and high-pressure heavy-duty pipeline systems.
 

2 Classification by Sealing Type

Soft-Seal Segment Ball Valve: Adopts polymer sealing materials, achieving zero leakage shutoff, suitable for clean water, gas, oil, and other low-abrasion media, with low cost and good sealing performance.

Hard-Seal Segment Ball Valve: Adopts metal alloy hard sealing pairs, resistant to high temperature, high pressure, abrasion, and corrosion, suitable for slurry, high-temperature steam, corrosive chemical media, and other harsh working conditions.