Ball Valve Overview: from Structure & Material to Type & Selection

A ball valve is a valve widely used in pipe fluid or gas transmission systems. It is named after its valve clack type and is commonly used in various water supply pipe systems and irrigation systems to regulate the flow of fluids or gasses. The pass of the medium is usually controlled or cut off by opening and closing the ball valve. 

Basic Structure

The ball valve is mainly composed of valve stem, ball, valve seat, sealing ring and housing. 

• Valve Stem: Used to open or close the ball valve. When the valve stem is parallel to the valve body, the ball valve is in the open state. When the valve stem is perpendicular to the valve body, the ball valve is in the closed state. 

• Ball: Inside the valve, there is a sphere with a hole. The direction of the hole in the sphere is controlled to control the pass of the medium or prevent the pass of the medium. 

• Valve Seat: The valve seat is usually located around the ball inside the valve, supporting the ball and ensuring that the ball and the valve form a tight seal.

• Sealing Ring: Usually located between the valve stem and the valve body, ensuring that the transmitted medium does not leak from the direction of the valve stem.

• Housing: Used to support and protect all ball valve components.

Material Selection

Usually, ball valves of different materials are selected according to different application environments and transmission media types. 

Common ball valve material types include: stainless steel, carbon steel, brass and plastic, etc. 

• Stainless Steel: It has excellent corrosion resistance and high temperature resistance. It is very suitable for use in high temperature and high pressure environments and environments full of corrosive fluids. It is often used in industries such as petroleum, chemical and marine. 

• Carbon Steel: Compared with stainless steel, it has poor corrosion resistance, but good strength and is suitable for use in environments with low corrosiveness. It is usually used in industries with low corrosiveness such as water supply and natural gas. 

• Brass: Good corrosion resistance, suitable for use in medium and low pressure environments, commonly found in pipes for household water supply pipes, air conditioning and HVAC systems.

• Plastic: Lightweight, very portable, corrosion resistant, and cost-effective. Commonly used in medium and low pressure and temperature environments in water treatment systems, agricultural irrigation systems, and household water systems. 

Working Principle

The opening and closing of the ball valve is controlled by the valve stem above. The valve stem can control the holed ball inside the ball valve to rotate at an angle of 90° to determine whether the fluid can pass through or block the fluid. 

When the direction of the valve stem is parallel to the ball valve, the ball valve is in an open state, and the internal fluid medium can pass smoothly without obstruction. When the direction of the valve stem is perpendicular to the ball valve, the ball valve is in a closed state, and the flow of the internal fluid is cut off and the fluid cannot pass. 

Ball Valve Types

According to different driving methods, ball valves can be divided into manual ball valves, electric ball valves, pneumatic ball valves, hydraulic ball valves and pneumatic-hydraulic ball valves. 

Manual Ball Valve

It is the most common type of ball valve. The valve stem is manually operated to control the opening and closing of the ball valve. It is suitable for low-pressure, small-diameter household water pipe systems, etc. The manual ball valve has a simple structure and is easy to operate, but it is not suitable for systems that require remote control. 

Electric Ball Valve

The valve stem is driven by electricity to control the opening and closing of the ball valve. Electric ball valves are suitable for fluid and gas transmission systems that require remote control, and are commonly used in industries such as petroleum, chemical and natural gas. 

Pneumatic Ball Valve

The valve stem is driven and operated by compressed air, and the opening and closing speeds are very fast. Pneumatic ball valves are suitable for high-efficiency transmission systems that require fast operation, and can also be used in flammable and explosive environments. Commonly used in automation systems in the chemical, pharmaceutical and other industries. 

Hydraulic Ball Valve

The opening and closing of the ball valve is controlled by hydraulic drive, which is particularly suitable for use in high-pressure environments and high-precision control environments. Hydraulic ball valves are widely used in large and complex equipment and systems. 

Pneumatic-Hydraulic Ball Valve

The pneumatic-hydraulic ball valve has the advantages of both pneumatic ball valves and hydraulic ball valves, and controls the opening and closing of the ball valve through the combined action of compressed air and hydraulic pressure. It is suitable for environments with high requirements for system safety and stability, and is often used in systems in fields such as petrochemicals. 

Selection Points

When selecting a ball valve, you need to consider many factors to ensure that it can meet the various requirements of the corresponding system. The following are some common considerations. 

• Fluid Medium: Before selecting a ball valve, you must first determine the type of fluid medium to ensure that the selected ball valve material is compatible with the transmitted medium or corroded. 

• Working Pressure and Temperature Range: Some ball valves have limited pressure resistance and applicable temperature range, so you need to confirm the data before choosing to avoid choosing an inappropriate ball valve. 

• Cost: If it is a conventional application environment, you can choose a conventional cost-effective manual control ball valve to keep the cost budget within a controllable range. However, if it is an application system with high requirements for ball valve performance, you need to choose the corresponding ball valve. You should not choose a low-cost ball valve that does not meet the requirements, which will only lead to bad results. 

Conclusion

Ball valves come in a wide variety of materials and types. When you choose a ball valve for your industry or system, you can consult our professional team. We will provide you with the most suitable ball valve according to your needs to ensure the stable operation of your system.