How does a floating ball valve seal

Floating ball valves are valves with a spherical body and no fixed axis. They are primarily used in industrial automation control systems in the papermaking, petrochemical, chemical, metallurgical, electric power, and petroleum industries. They feature two flow configurations: full-bore and reduced-bore. The ball rotates 90° with the valve stem to control the flow of media. They offer low flow resistance and are suitable for a variety of fluid environments, including water, steam, oil, acids, bases, and oxidizing media.

Sealing Principle of a Floating Ball Valve

The core component of a floating ball valve is a spherical opening and closing member with an internal through-hole that matches the pipe diameter. PTFE (polytetrafluoroethylene) sealing seats are mounted on each end of the spherical opening and closing member-the inlet and outlet-and are enclosed within the metal valve body. When the spherical opening and closing member rotates 90°, aligning its through-hole with the pipeline, the valve is open; otherwise, it is closed.

In the closed state, the medium pressure acts on the ball, generating a force that forces it to fit tightly against the sealing seat at the outlet. This contact stress generated by the medium pressure creates a contact zone on the conical surface of the sealing seat. The force per unit area of this contact zone is the valve's operating pressure, q. When this pressure exceeds the minimum required for sealing, the valve is effectively sealed. This type of sealing, which relies on the medium's own pressure, is known as media self-sealing.

Features of Floating Ball Valves

1. High Valve Density and Excellent Sealing: Floating ball valves utilize a special design to achieve sealing with various precision levels, thus ensuring valve sealing performance.

2. Wide Floating Range: Floating ball valves utilize a spherical structure, enabling a 360-degree floating range and preventing the valve from leaking due to asymmetric media.

3. Wide Application Range: Floating ball valves are suitable for use in special operating conditions such as high flow rates, highly corrosive media, high temperatures, and high pressures.

4. Self-Cleaning Function: Floating ball valves utilize a spherical structure to prevent media accumulation and residue, thus achieving a self-cleaning function.