Floating Ball Valve: Main Advantages and Design Considerations
The main advantages of floating ball valves are their simple structure, ease of manufacture, low cost, and reliable operation. The sealing performance of a floating ball valve is related to fluid pressure. Under the same conditions, generally speaking, the higher the pressure, the easier it is to achieve sealing. However, consideration must be given to whether the seat material can withstand the load transmitted by the ball, as the force generated by fluid pressure on the ball is entirely transferred to the downstream seat.The main Ball valve product names of China Ball valve Network include:Flange Copper Ball Valve，Flange Fluorine-lined Ball Valve，Forged Brass Ball Valve (Butterfly Handle Type)，Forged Steel Anti-sulfur Fixed Ball Valve，GB/ANSI Three-way Ball Valve
Furthermore, for larger-sized floating ball valves under high pressure, the operating torque increases significantly. The ball's own weight also becomes substantial, creating uneven pressure distribution on the seat sealing surface—typically, along the horizontal plane of the channel diameter, pressure is lower on the upper half and higher on the lower half. This uneven distribution causes uneven seat wear, eventually leading to leakage. Therefore, floating ball valves are generally suitable for applications with nominal pressure ≤ PN10 and nominal diameter ≤ DN200.
Preload Requirements for Low-Pressure Applications
To ensure good sealing performance under low operating pressures, a certain preload must be applied between the ball and the seat. Insufficient preload cannot guarantee sealing, while excessive preload increases friction torque and may cause plastic deformation of the seat material, damaging the sealing performance. For low-pressure ball valves, the preload can be controlled by adjusting the thickness of the gasket between the body flanges.Ball Valve Technology
Key Design Considerations
To ensure sealing performance and reliability during operation, the following points should be considered in design:Ball Valve Suppliers
a. Sufficient specific sealing pressure must exist on the contact surface between the ball and seat to meet sealing requirements.
b. The specific sealing pressure between the seat and the bottom surface of the body groove should be equivalent to that on the ball contact surface. If insufficient, it can be improved by reducing the outer diameter or increasing the inner diameter of the seat bottom.
c. The ball must have correct geometric shape and appropriate surface roughness.
d. Seal materials should be selected reasonably.
Advanced Solution: Elastic Seat Design
Currently, an ideal method for applying preload is using elastic valve seats. Elastic seats significantly increase the elastic deformation range of the seat itself, enabling good sealing performance under both low and high pressures. As long as operation remains within the elastic deformation range of the seat, the specific sealing pressure remains essentially constant, preventing seat damage from overload.
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