A 3 Piece Floating Ball Valve is characterized by its body, which consists of three main sections: the two end caps and a central body piece that houses the floating ball. This modular design facilitates maintenance and part replacement without removing the entire valve from the pipeline.
Structure and Operation
The defining feature of this valve is its floating ball, which is suspended between two resilient seats without support from a fixed trunnion. The ball is free to move slightly within the valve body, and under pressure, it is pushed against the downstream seat to form a tight seal. This pressure-assisted sealing mechanism makes the valve suitable for bi-directional flow and moderate pressure applications.
Key Features
Ease of Maintenance: The three-piece design allows for the removal of the center body section, providing convenient access to internal components like the seats, seals, and ball.
Compact Sealing Mechanism: The floating ball ensures tight shut-off by relying on pressure to force the ball into the seat.
Materials: Typically constructed using stainless steel, carbon steel, or other alloys with soft seat materials such as PTFE or RTFE for chemical compatibility.
Applications
3 Piece Floating Ball Valves are suitable for low to medium pressure systems in industries like food and beverage, water treatment, pharmaceuticals, and light chemical processing. Their cleanability and ease of disassembly also make them ideal for systems requiring frequent maintenance or cleaning.
The 3 Piece Trunnion Mounted Ball Valve shares the modular body design of the floating type, but it features a trunnion-mounted ball mechanism. In this configuration, the ball is fixed in place by trunnion supports and does not float downstream under pressure.
Structure and Operation
Trunnion-mounted valves have the ball anchored by shafts at the top and bottom. Instead of relying on the pressure to push the ball into the seat, the seats are spring-loaded or pressure-energized to move toward the ball. This enables the valve to maintain consistent sealing performance regardless of the flow pressure.
Key Features
Low Operating Torque: Because the ball does not bear the pressure load, less torque is needed to operate the valve, which reduces actuator size and cost.
Reliable Sealing: Double-block-and-bleed capability is often built into these valves, allowing for superior safety and isolation.
Pressure Management: Well-suited for high-pressure applications due to the trunnion support that absorbs flow-induced forces.
Maintenance and Modularity
Like its floating counterpart, the 3 piece trunnion mounted valve allows for the replacement of internal components without disrupting the entire pipeline system. This feature is valuable in large-scale or hazardous environments where downtime must be minimized.
Applications
These valves are widely used in oil and gas, petrochemical, and power generation industries. Their high pressure and temperature handling capabilities make them a standard choice for critical operations in transmission pipelines and offshore platforms.
Comparative Summary
Feature 3 Piece Floating Ball Valve 3 Piece Trunnion Mounted Ball Valve
Ball Support Free-floating Trunnion-mounted (fixed)
Pressure Range Low to medium Medium to high
Seat Movement Stationary seat, moving ball Spring/pressure-loaded seats, fixed ball
Operating Torque Higher due to pressure-assisted sealing Lower due to mechanical support
Maintenance Easy due to 3-piece design Easy, though internal structure more complex
Applications Clean fluids, lower pressure systems Oil & gas, high-pressure industrial systems
Cost Generally lower Higher due to complex structure and materials
English 
русский 
Español 
عربى 
