Selecting the correct ball valve design is a fundamental decision in pipeline engineering. Two prevalent designs are the floating ball valve and the trunnion ball valve, each possessing distinct mechanical principles and application suitability. For manufacturers like Neway Valve, which produces both China stainless steel floating ball valves and trunnion models, understanding this distinction is crucial for system integrity.
The Fundamental Mechanical Principle
The core difference lies in how the ball is supported and transfers force. In a floating ball valve, the ball is free to move or “float” slightly along the vertical axis. System pressure from the upstream side pushes the ball against the downstream seat, creating a mechanical seal. This design is effective for lower to medium pressure applications. The construction of a floating ball valve relies on the seat material’s resilience to maintain sealing under this pressure.
Application in High-Pressure Environments
A trunnion ball valve incorporates a fixed ball, supported by a shaft or “trunnion” at the top and bottom. This anchoring prevents the ball from shifting under pressure. Instead of relying on line pressure to create the seal, the seats are spring-loaded and pushed against the stationary ball. This mechanism makes the trunnion design superior for high-pressure and large-diameter pipelines, a critical consideration for industrial valve selection beyond the scope of standard China stainless steel floating ball valves.
Maintenance and Operational Longevity
The operational forces and wear patterns differ between the two types. The sliding motion and pressure-assisted sealing in a floating ball valve can lead to higher seat wear over time, especially during frequent cycling. The trunnion valve’s fixed ball and mechanically actuated seats result in lower operating torque and reduced seat wear, enhancing its service life in demanding, high-cycle duties. This impacts long-term maintenance schedules and total cost of ownership.
The choice between a floating and trunnion ball valve is not a matter of superiority but of correct technical application. The decision hinges on specific operational parameters: pressure class, pipe diameter, and required cycle life. Engineers specify a floating ball valve for its cost-effectiveness and reliability in standard duties, while turning to trunnion models for more severe service conditions. Manufacturers like Neway Valve provide both designs to meet this spectrum of industrial requirements.
