Trunnion Ball Valve vs Floating Ball Valve 

UAE Valves is leading provider of high quality industrial valve, ensuring efficient fluid control in various industry including oil & gas, water treatment, power generation and chemical processing. Among many valve type- ball valve are widely used for durability, reliability and tight sealing capability. Two most common type are trunnion ball valve and floating ball valve. While both serve similar function, they differ significantly in design, operation and application.  

Understanding Difference Between Trunnion Ball Valve & Floating Ball Valve  

Ball Valve 

It is type of quarter turn valve that use a spherical ball with hole (bore) through center to control fluid flow. When the hole align with pipeline, valve allow fluid to pass; when turned 90 degree, solid part of the ball block flow. Ball valve are known for great sealing capability, easy operation and low maintenance requirement.  

There are two primary type of ball valve-  

1. Trunnion mounted ball valve 

2. Floating ball valve   

Trunnion Ball Valve  

Key Parts of Trunnion Ball Valve  

1. Body: The outer casing that houses all internal components.  

2. Ball: A fixed ball with a bore that controls fluid flow.  

3. Trunnion: Mechanical support that holds the ball in position.  

4. Stem: Connects the actuator or handle to the ball.  

5. Seats: Spring-loaded seats that ensure a tight seal.  

6. Handle/Actuator: Used to rotate the ball and control fluid flow.  

Working Mechanism  

Trunnion ball valve operate by rotating  ball within valve body. When the handle or actuator is turned 90 degrees, the ball bore align with flow path, allowing fluid to pass. When rotated again, the solid part of the ball blocks the flow. The trunnion design provides extra support, reducing the torque required for operation. 

Design and Structure  

Trunnion ball valve has additional mechanical anchoring, known as a trunnion – at both top and bottom of ball. This design provide extra support, especially for larger and high pressure application. The ball remain fixed in place while the seat ring move to create seal.  

Key Feature of Trunnion Ball Valve  

• Fixed Ball Design: The ball is held in place by trunnion, reducing movement and minimizing operational torque.  

• Spring Loaded Seats: The seat are spring loaded to ensure tight sealing, even in high pressure condition.  

• Lower Operating Torque: Since the ball is supported, it require less force to operate, making it ideal for automation.  

• High Pressure Performance: Suitable for application involving high pressure and large pipeline system.  

• Double Block and Bleed (DBB): Offer enhanced safety by isolating upstream and downstream fluid flow.  

Advantage of Trunnion Ball Valve  

• Handle high pressure application efficiently.  

• Require less force to operate, reducing actuator size and cost.  

• Provide superior sealing, preventing leak even in extreme condition.  

• Available in larger size for industrial application.  

Common Application of Trunnion Ball Valve  

1. Oil and gas pipeline  

2. Refining and petrochemical industry 

3. Power plant  

4. Large scale water distribution system 

Floating Ball Valve  

Key Part of Floating Ball Valve  

1. Body: The outer shell that hold valve component.  

2. Ball: A free moving ball with bore for fluid passage.  

3. Stem: Connect actuator or handle to the ball.  

4. Seats: Elastomeric seat that provide sealing function.  

5.  Handle/Actuator: Used to rotate ball and control flow.  

Working Mechanism 

In floating ball valve, the ball is suspended between two seat. When the handle is turned, the ball rotates, aligning its bore with the pipeline to allow fluid to pass. When turned 90 degrees, the solid side of the ball blocks the flow. The ball’s slight movement ensures a better seal when fluid pressure increases.  

Design and Structure  

Floating ball valve feature ball that is not fixed by trunnion. Instead, it is suspended and held in place by the two elastomeric seat, allowing it to move slightly within valve body. When pressure is applied, the ball is pushed against the downstream seat, creating seal. 

Key Feature of Floating Ball Valve  

• Unanchored Ball: The ball is free to move slightly within valve body.  

• Seat Dependent Sealing: The ball rely on fluid pressure to press against the seat for sealing.  

• Compact Design: Suitable for small to medium sized pipeline.  

• Simple Construction: Fewer component result in easier maintenance.  

• Manual and Automated Operation: Can be operated using hand lever or an actuator.  

Advantage of Floating Ball Valve  

• Cost effective & easy to manufacture.  

• Compact and lightweight, making it suitable for space-constrained application.  

• Provide tight shutoff in low to medium pressure system.  

• Easy to maintain due to simple design.  

Common Application of Floating Ball Valve  

1. Water & wastewater treatment  

2. Chemical industries  

3. Low to medium pressure oil & gas application 

4. HVAC system 

Key Differences Between Trunnion Ball Valve and Floating Ball Valve 

Conclusion 

Both trunnion ball valve and floating ball valve play vital role in industrial fluid control. While trunnion ball valve are ideal for high pressure and large scale operation, floating ball valve provide cost effective solution for lower pressure application. Understanding their difference helps in selecting the right valve for your industry need.  

uaeadmin

See Full Bio