Metal Seated Floating Ball Valves: Performance and Applications

 
A metal seated floating ball valve is a highly advanced and widely used piece of equipment in various industrial fields. Known for its exceptional sealing performance and durability, this ball valve can operate reliably under extreme temperatures, pressures, and complex media conditions. By utilizing a unique spring-loaded structure and precision manufacturing processes, the ball valve effectively addresses issues such as thermal expansion, contraction at low temperatures, and the impact of solid particles on the sealing surface. This ensures reliable operation and long service life in harsh environments. As a result, metal seated floating ball valves have found extensive applications in industries such as chemical processing, oil and gas, power generation, and metallurgy, becoming an indispensable control component in many industrial systems.

Structural Features and Operating Principles

 
The design of a metal seated floating ball valve typically employs an outlet-end sealing structure. This means that the valve seat at the inlet end is loaded by a plate spring or compression spring, without traditional sealing elements between the valve body and the seat. This design allows the valve body, ball, and seat to deform freely under high or low temperatures without affecting the valve's normal opening and closing, preventing the ball and seat from sticking due to thermal expansion and contraction.
 
When the valve is in a closed position, both the spring force and the pressure of the medium act on the ball, pushing it against the outlet end seat, ensuring reliable sealing performance under both low and high-pressure conditions. At low pressures, the valve relies mainly on the spring force to maintain a seal, while at high pressures, the medium pressure further enhances the sealing effect.

Superior Sealing Performance

 
Metal seated floating ball valves are renowned for their low operating torque and high sealing reliability. To handle various harsh conditions, the ball and seat can be made from various materials and surface-treated using different techniques. For example, the sealing surfaces of the ball and seat can undergo hardening processes such as carbide spraying, HVOF (High-Velocity Oxy-Fuel) coating, and nickel-based alloy welding, giving them high resistance to temperature, wear, and corrosion.
 
Additionally, the design of metal seated floating ball valves incorporates self-cleaning and shearing functions, enabling them to effectively control fluids containing solid particles and fibrous media. These features not only extend the valve’s service life but also ensure stability and reliability when operating in media with impurities.

Materials and Manufacturing Processes

 
The exceptional performance of metal seated floating ball valves is achieved through the use of advanced materials and manufacturing techniques. The ball and seat use a metal-to-metal sealing method, and various surface hardening treatments are applied according to different usage requirements to enhance durability and sealing performance.

1. Surface Hardening Treatment Techniques

 
Several surface hardening treatments are utilized to enhance the hardness and wear resistance of the sealing surfaces.
 
High-Velocity Oxy-Fuel (HVOF) Coating: This technique involves spraying hard alloy powder at high speeds to form a dense, wear-resistant coating on the sealing surfaces.
 
Nickel-Based Alloy Weld Overlay: Nickel-based alloys are used to overlay weld the sealing surfaces, improving corrosion resistance and high-temperature performance.
 
Hard Alloy Weld Overlay: Hard alloy materials are weld overlaid onto the sealing surfaces to increase hardness and wear resistance.
 
Special Surface Hardening Treatments: Techniques such as ion implantation and surface quenching are used to further enhance the surface strength and wear resistance of the materials.
 
High-Strength, High-Hardness Ceramic Materials: These materials are used in extreme conditions to improve wear resistance and corrosion resistance.

2. Performance Characteristics

 
These treatment processes allow the surface hardness of the ball and seat to reach above HRC60, ensuring reliable sealing performance in high-temperature and high-pressure environments. The sealing surface materials are not only resistant to high temperatures but also have excellent wear and impact resistance, enabling metal seated floating ball valves to withstand most harsh conditions.

3. Ball Grinding Process

 
To further ensure a good sealing performance between the ball and seat, metal seated floating ball valves employ an advanced ball grinding process. By rotating the ball against grinding tools from different spatial orientations, this process achieves a high degree of roundness and surface finish for the ball, significantly enhancing the valve's sealing effectiveness and operational stability.
 
The precise combination of material selection and manufacturing processes allows metal seated floating ball valves to excel in various industrial applications, ensuring high performance and long service life under extreme conditions.

Common Applications

 
Thanks to their superior versatility and high reliability, metal seated floating ball valves are suitable for a wide range of complex industrial applications, demonstrating extensive applicability in high-temperature, low-temperature, ultra-high-pressure environments, as well as in conditions containing solid particles and fibers.

1. Low-Temperature Applications

 
These valves are suitable for controlling media in low-temperature environments, with media temperatures down to -196°C. The valve body and internal components are cryogenically treated and designed with extended bonnets to ensure proper operation at extremely low temperatures, achieving zero gas leakage.

2. High-Temperature Applications

 
Suitable for controlling media in high-temperature environments, with media temperatures up to +650°C. The valve body and internal components are made from high-temperature-resistant special alloy steel and undergo specialized heat treatment processes to ensure stable operation under high temperatures, still achieving zero gas leakage.

3. Thermal Power Applications

 
In the main steam systems of thermal power generation units, valves are required to maintain tight shut-off under high temperatures and pressures for extended periods to prevent corrosion damage from steam condensate to pipelines and equipment. Metal seated floating ball valves meet these stringent requirements, providing efficient and reliable sealing performance.

4. Severe Service Applications

 
In ultra-high-pressure environments containing dust, solid particles, and fibrous media, metal seated floating ball valves demonstrate excellent adaptability. Their metal-seated structure and special surface treatments ensure reliable operation under various extreme conditions.
 
With their unique design, quality material selection, and advanced manufacturing processes, metal seated floating ball valves exhibit outstanding performance and reliability under various harsh conditions. Whether dealing with extreme temperatures, ultra-high-pressure environments, or controlling complex media with particles and fibers, these valves provide stable sealing performance and long service life, making them a preferred choice in many industrial applications. With continuous optimization and innovation, this type of valve will continue to meet the increasingly stringent industrial demands of the future.