Floating Ball Valve
What are the Different Types of Floating Ball Valves?
Floating ball valves can be classified according to different classification standards, mainly including the following ways:
1. By Design
- Standard Floating Ball Valve: The ball "floats" within the valve body, and the pressure of the media pushes the ball against the seat to form a seal.
- Double-Block and Bleed Floating Ball Valve: Features two sealing surfaces and a bleed port to vent the trapped fluid between them, providing double isolation.
- Top-Entry Floating Ball Valve: Allows maintenance and servicing by removing the valve body from the top, offering ease of access and reduced downtime.
2. By Actuation
- Manual Floating Ball Valve: Operated manually by rotating the ball to control the flow.
- Electric Floating Ball Valve: Uses an electric actuator to control the ball’s position (open/close), suitable for automation and remote operation.
- Pneumatic Floating Ball Valve: Controlled by a pneumatic actuator, ideal for automated or remote-controlled systems.
3. By Application
- Fire-Safe Floating Ball Valve: Designed to prevent leakage and maintain function during a fire, typically featuring metal-to-metal seals for reliability.
- Cryogenic Floating Ball Valve: Made for extremely low temperatures, often used in liquefied natural gas (LNG) and cryogenic industries, typically with materials that withstand sub-zero conditions.
- High-Pressure Floating Ball Valve: Built for high-pressure applications with reinforced sealing to withstand higher pressures.
4. By Valve Body Material
- Carbon Steel Floating Ball Valve: Common in general industrial applications, offering a balance between performance and cost.
- Stainless Steel Floating Ball Valve: Used where higher corrosion resistance and temperature endurance are required.
- Alloy Floating Ball Valve: Designed for special conditions, such as highly corrosive environments or extreme temperatures, using materials like Inconel or Monel.
What are the Valve Body Styles of Floating Ball Valves?
Floating ball valves can also be classified based on the valve body style. The main body styles include:
1. Two-Piece Floating Ball Valve
The valve body consists of two parts—body and bonnet—making it compact and easy to maintain.
Advantages:
- Simple Design: Easy to assemble and disassemble.
- Cost-Effective: Budget-friendly for lower pressure systems.
- Easy Maintenance: Facilitates quick servicing and repair.
Applications: Commonly used in general industrial and low-to-medium pressure systems.
2. Three-Piece Floating Ball Valve
The valve body consists of three parts: two body halves and a middle section containing the ball. The middle section can be removed for easier maintenance or part replacement without disturbing the entire valve assembly.
Advantages:
Easy Maintenance: Simplifies servicing by allowing part replacement without full valve disassembly.
Modular Design: The middle section can be replaced independently.
Applications: Common in higher pressure applications and systems requiring regular maintenance.
3. Full Port Floating Ball Valve
The valve's internal diameter matches the pipeline diameter, providing an unobstructed flow path.
Advantages:
Minimal Pressure Drop: Ensures low resistance and smooth flow.
Unrestricted Flow: No flow restrictions, maximizing capacity.
Applications: Ideal for systems that require maximum flow capacity and minimal pressure loss.
4. Reduced Port Floating Ball Valve
The valve has a smaller internal diameter than the pipeline, restricting the flow.
Advantages:
Compact: Smaller design suitable for tight spaces.
Cost-Effective: Lower manufacturing cost compared to full port valves.
Suitable for Lower Flow: Effective in applications where flow restrictions are acceptable.
Applications: Used in lower flow or non-critical applications where flow restriction is not an issue.
5. Split-Body Floating Ball Valve
The valve body is constructed with multiple pieces (usually two or three), sealed with a bolted connection.
Advantages:
Easy Maintenance: Quick access for servicing and part replacement.
High Integrity: Strong sealing and robust design.
Pressure Handling: Can withstand high-pressure and high-temperature conditions.
Applications: Typically used in high-pressure and high-temperature systems.
Is a Floating Ball Valve Bidirectional or Unidirectional?
A floating ball valve is usually bidirectional, meaning that it can control fluid flow in both directions.
The ball inside the valve "floats" and is pushed toward the seat by the pressure of the fluid, regardless of the direction of flow.
In addition to the common bidirectional floating ball valve, there may be a preferred flow direction in the design of the floating ball valve depending on the arrangement of the seat or sealing mechanism. This is particularly important in valves with features such as double block and bleed, where flow direction may affect sealing efficiency.
Are Floating Ball Valves Fire Safe?
Floating ball valves can be specially designed to be fireproof floating ball valves, but not all floating ball valves are fireproof. You can check with the valve manufacturer to find out if its design meets specific industry fire protection standards:
API 607: American Petroleum Institute valve fire test standard.
ISO 10497: International standard for testing valves for fire protection.
These certifications ensure that the valves work properly under fire conditions and meet safety regulations.
How Many Seats are There in a Floating Ball Valve Design?
Standard floating ball valves usually have two seats.
General case: The ball is located between two seats, one on each side, and the seats provide the sealing surface.
Special case: In some special designs, such as double block and bleed valves, there may be additional seats or sealing surfaces.
Can Floating Ball Valves be Used in Uigh Pressure Applications?
Floating ball valves can be used in high pressure applications, but they may not be the best choice for extreme pressures.
For ultra-high pressure systems, trunnion ball valves or gate valves may be more appropriate because they provide better stability and sealing under high pressure conditions.
What are the Two Seat Technologies Used in Floating Ball Valve Designs? What is the Difference?
There are two primary types of seating technology: the jam seat and the flexible or energized seat.
1. Jam Seat Design
How It Works: The jam seat uses extra material that compresses when the ball is pressed into it during assembly, causing plastic deformation to create a seal against the ball and body wall.
Pressure Sealing: As pressure increases, the ball presses harder into the downstream seat, tightening the seal—though this only holds as long as the pressure remains high.
Challenges:
Cold Flow: When pressure drops, the seat cannot return to its original shape, risking leakage.
Temperature Sensitivity: PTFE and TFM in jam seats expand more than metal with heat, potentially causing deformation and leakage as the valve cools.
Wear: Jam seats lack wear compensation and may degrade quickly under high-cycle, high-pressure conditions.
2. Flexible (Energized) Seat Design
How It Works: Flexible seats use elastic deformation, with a flexure zone that allows bending to absorb energy and maintain a seal.
Advantages:
Compensation: The elastic design adapts to pressure and temperature changes, reducing permanent deformation and leakage.
Durability: The flexure zone prevents cold flow, making the design more resilient under varying pressures and temperatures.
Jam Seat Design VS Flexible (Energized) Seat Design
Jam Seat Design:
Jam seats are simpler and effective for low-pressure applications but may experience permanent deformation under high pressure or temperature changes.
Flexible (Energized) Seat Design:
Flexible seats are more advanced, featuring built-in elasticity for pressure, temperature, and wear compensation, making them ideal for applications with varying conditions.
What is the Design Standard for Floating Ball Valves?
The design standards for floating ball valves are established by various international organizations to ensure safety, compatibility and reliability.
The main standards include:
API 6D (Specification for Pipeline Valves): Covers the design, manufacture, and testing of ball valves used in pipeline applications, with a focus on safety and operational integrity.
API 608 (Metallic Ball Valves for General Industrial Use): Specifies requirements for floating ball valves used in industrial applications, including materials, dimensions, and performance.
ASME B16.34 (Valves - Flanged, Threaded, and Welding Ends): Defines minimum requirements for pressure-temperature ratings, materials, and valve design for various types of valves, including floating ball valves.
ISO 17292 (Metallic Ball Valves for Petroleum, Petrochemical, and Allied Industries): Provides international standards for floating ball valves used in the petroleum, gas, and petrochemical industries, covering dimensions, pressure ratings, and material compatibility.
MSS SP-72 (General Purpose Flanged or Welding End Ball Valves): Specifies design and performance criteria for floating ball valves for general applications, often used in conjunction with API and ASME standards.