Ball Valve Overview

The ball valve evolved from the plug valve. Its closing element is a spherical ball that rotates 90° around the valve stem axis to open or close the valve. Unlike plug valves, the ball valve’s plug is spherical with a circular bore or passage running through its axis. When the ball rotates 90°, the inlet and outlet are completely blocked by the solid ball surface, effectively stopping fluid flow.

In pipeline systems, ball valves are mainly used for shut-off, distribution, and changing the flow direction of the medium. Ball valves designed with a V-shaped opening can also provide excellent flow regulation, making them suitable not only as shut-off valves but also as control valves in certain applications.

Structure and Performance Advantages

Ball valves feature a compact structure and excellent sealing performance. Within a certain nominal diameter range, they are characterized by small size, light weight, low material consumption, and reduced installation dimensions. They require a small operating torque, enabling easy and quick operation. These advantages have made ball valves one of the fastest-growing valve types over the past decade.

In industrialized countries such as the United States, Germany, France, Italy, Spain, and the United Kingdom, ball valves are widely used, with both variety and volume continuously increasing. Modern ball valves are evolving towards high temperature, high pressure, large diameter, high sealing capability, long service life, superior flow regulation, and multifunctionality. Their reliability and performance have reached advanced levels, and in some applications, they are gradually replacing gate valves, globe valves, and control valves.

Ball valves achieve tight shutoff with only a 90° rotation requiring minimal torque. The straight-through flow path inside the valve provides an almost unobstructed flow passage. Although traditionally used for on/off control, technological improvements have enabled some ball valves to perform throttling and flow control functions. Their compact design and easy maintenance make them suitable for conventional media such as water, solvents, acids, and natural gas, as well as stable operation under harsh media conditions like oxygen, hydrogen peroxide, methane, and ethylene. Ball valve bodies can be either integral or modular designs.

Application Prospects

With continuous technological advancements, ball valves will see expanded use in oil and gas pipelines, refining and cracking units, as well as the nuclear industry. Additionally, in other industrial sectors involving medium to large diameters and medium to low pressure conditions, ball valves are expected to become one of the mainstream valve types.

Advantages of Ball Valves

• Low Fluid Resistance: Their resistance coefficient is nearly equivalent to that of a straight pipe of the same length.

• Compact Structure and Lightweight: Small in size and easy to install.

• Excellent Sealing Performance: Sealing surfaces often use high-performance materials like plastics, ensuring good performance even in vacuum systems.

• Easy Operation: Quick on/off action with only a 90° rotation, suitable for remote control.

• Convenient Maintenance: Simple structure with usually replaceable sealing rings, facilitating disassembly and servicing.

• Sealing Surface Protection: In fully open or fully closed positions, the sealing surfaces of the ball and seat are isolated from the media, reducing erosion risk.

• Wide Application Range: Applicable to nominal diameters from a few millimeters to several meters, and suitable for conditions from high vacuum to high pressure.

Common Questions Q&A

Q1: Is a ball valve suitable for frequent flow regulation?
A: Generally, ball valves are not recommended for frequent throttling unless specifically designed as V-port ball valves for regulation. Frequent adjustment may accelerate sealing surface wear.

Q2: Can ball valves be used for high-temperature or high-pressure media?
A: Yes, provided that appropriate body and sealing materials are selected. For example, metal-seated ball valves are suitable for high-temperature and high-pressure conditions.

Q3: What are common causes of leakage when a ball valve is closed?
A: Common causes include damaged sealing rings, worn ball surfaces, or foreign objects causing blockage. Cleaning, replacement, or repair should be performed based on the situation.

Q4: Are ball valves suitable for media containing particles?
A: For media with suspended particles, wear-resistant metal-seated ball valves should be used, along with regular flushing and maintenance to extend service life.

Q5: What is the biggest advantage of ball valves compared to gate valves?
A: Ball valves offer faster operation, smaller size, better sealing performance, and are easier to automate and control remotely.