A Guide to Choose Between Trunnion Mounted & Floating Ball Valves
Ball valves are essential components in fluid control systems across industries, from oil and gas to water treatment and manufacturing. When choosing a ball valve, it’s important to select the right type to ensure overall optimised performance and results.
Two common types of ball valves are Trunnion Mounted and Floating Ball Valves. Understanding the key differences and how they function can help you make the right choice for your specific application.
What Are Trunnion Mounted Ball Valves?
Trunnion mounted ball valves have a ball that is anchored at the top and bottom, meaning the ball is held in place by a trunnion, which reduces the stress and wear on the valve seals. This design provides excellent support for the ball, particularly in high-pressure applications, where it becomes important to minimise movement.
Key Features of Trunnion Mounted Ball Valves
Support System: A mechanical anchor (trunnion) supports the ball, reducing torque required for operation.
High Pressure Handling: These valves are ideal for high-pressure systems as the design distributes forces more evenly, ensuring longer service life and reduced maintenance.
Low Operating Torque: Due to the anchored ball, less torque is needed to operate the valve, which is particularly advantageous in large-diameter valves.
Double-Block and Bleed Functionality: Trunnion valves often come with the capability to shut off flow from both ends of the valve and release trapped pressure in the cavity between the seats.
Applications
- Oil and gas pipelines
- High-pressure gas and liquid services
- Subsea systems
- Industrial applications that require precise flow control
What Are Floating Ball Valves?
In contrast, floating ball valves have a ball that is suspended between two seats and is not anchored. Hence, it earns its name ball float valve.
The ball "floats" slightly, which allows it to move in response to pressure differences in the pipeline. This movement helps the ball press against the downstream seat to create a seal.
Key Features of Floating Ball Valves
Simple Design: These valves have a simpler design compared to trunnion-mounted valves, making them more affordable.
Effective Sealing at Low Pressure: The floating ball design provides excellent sealing under low to moderate pressure.
Seat Wear: The ball’s movement can cause more wear on the seats over time, particularly in high-pressure applications, which might result in frequent maintenance.
Manual Operation: Floating ball valves are commonly used in applications where manual operation and lower pressure systems are suitable.
Applications
- Water treatment systems
- Low to moderate pressure pipelines
- Chemical and pharmaceutical industries
- Residential gas pipelines
Choosing The Right Valve for Your Application
Pressure Requirements:
For high-pressure applications, such as in oil and gas or petrochemical industries, a trunnion mounted ball valve is the better choice. Floating ball valves are typically preferred for lower-pressure systems.
Pipe Size:
Trunnion mounted valves are available in larger sizes, making them suitable for large pipelines, while floating ball valves are often used in smaller diameter pipelines.
Cost Consideration:
If budget is a key factor and the application does not require high-pressure handling, a floating ball valve is the cost-effective option.
Maintenance Needs:
Trunnion mounted valves are more durable and offer longer service life with less seat wear. It also makes them a good investment for systems where reduced maintenance is important.
Flow Control Precision:
For critical flow control applications that demand precision, trunnion mounted ball valves provide better performance, especially in high-pressure systems.
Consider these stark differences and make the right choice.