Valve as an industry is a pipeline accessory used to open and close the pipeline, control the flow, and regulate and control the parameters of the transported medium (temperature, pressure, flow).
There are many types of valves, including gate valves, globe valves, butterfly valves, ball valves, and plug valves. Next, we will introduce ball valve material selection, types, applications, and manufacturers of ball valves.
What is a ball valve?
A ball valve is a globe valve that controls the flow of a liquid or gas and is named for the spherical spool inside the valve. The main construction of a ball valve consists of a spherical spool with a hole and a seat that corresponds to the spool. When the spool is perfectly aligned with the seat, the fluid is free to pass through the valve. By rotating the stem or handle, the spool can be turned so that its bore is not aligned with the seat, thereby closing or restricting the flow of fluid. Ball valves are the most commonly used fluid shutoff valves in household appliances and offshore upstream oil and gas production facilities.
Types of Ball Valves
Ball valves are available in a variety of types and designs, including manual ball valves and automatic ball valves. These include full-pass ball valves, reduced-pass ball valves, and multi-way ball valves to meet the needs of different applications. They can be selected based on fluid media, temperature, pressure, and pipe size. Whether it’s ensuring maximum flow, precise flow control, high-pressure resistance, or versatile diversion, there is a ball valve configuration for every application. Understanding the different types of ball valves and their unique features is critical to selecting the most appropriate valve for a particular system or industry.
Full Bore Ball Valves
- Full-bore ball valves, also known as full bore ball valves, have a large ball with an orifice diameter equal to the inside diameter of the pipe. These valves provide unrestricted flow with minimal pressure drop, making them suitable for applications requiring maximum flow. Full bore ball valves are typically used in high flow pipelines, such as industrial processes and large water distribution systems.
Reduced Flow Ball Valves
- Compared to a full bore ball valve, a reduced bore ball valve has a smaller ball with an orifice diameter smaller than the pipe diameter. As a result, they have a smaller flow rate compared to full-pass valves. However, reduced ball valves are more compact and cost effective, making them suitable for applications where space and budget constraints exist. They are typically used in residential and commercial piping systems as well as small industrial applications.
V-Port Ball Valves
- V-port ball valves feature a specially designed ball with a V-shaped bore. This unique configuration allows for more precise flow control by providing varying degrees of opening. By adjusting the rotation of the ball, the flow can be throttled and precisely regulated. V-port ball valves are typically used in applications where precise control of flow and system performance is required, such as chemical processing, HVAC systems, and wastewater treatment.
Trunnion Mounted Ball Valves
- Trunnion-mounted ball valves are designed with additional mechanical anchoring of the ball at the top and bottom to ensure greater stability and support. These valves are typically used in larger sizes and high-pressure applications. Fixed ball valves offer excellent sealing capabilities and can withstand higher operating pressures for use in industries such as oil and gas, petrochemical, and power generation.
Multi-Port Ball Valves
- Multi-port ball valves, also known as manifold valves, have multiple ports on a single valve body. They include three-way ball valves, four-way ball valves, and five-way ball valves. Multiport ball valves are available in L- or T-port and X-port bore designs. They offer a variety of flow control options, allowing the transfer of flow between various inlets and outlets. Multi-port ball valves are typically used in applications where flow needs to be changed or redirected, such as distribution systems, process control, and mixing applications.
How a ball valve works
The ball valve consists of a spherical spool with a hole and a corresponding seat. The spool is located in the valve body, allowing fluid to flow freely when the spool and seat are aligned. The stem or handle is connected to the spool and can be rotated to align or misalign the hole with the seat, thereby controlling the flow of fluid.
Operation of the ball valve
When the spool is in the open position, the hole is aligned with the seat, creating a straight path for fluid flow. When the stem or handle is rotated, the spool turns, causing the hole to be misaligned with the seat, gradually restricting or shutting off fluid flow.
How to choose the housing material for ball valves
Common materials for ball valve housings include stainless steel, brass, bronze and various alloys.
Stainless steel
- Excellent corrosion resistance and durability.
- Resistant to a wide range of fluids, including corrosive and high-temperature liquids and gases.
- Suitable for use in a variety of industries, including chemical processing, oil and gas, pharmaceutical and food processing.
Brass
- Suitable for low-pressure applications involving non-corrosive fluids such as water, air and oil.
- Suitable for neutral and non-corrosive media.
- Good corrosion resistance, easy to manufacture and affordable.
Bronze
- Good corrosion resistance and wear resistance.
- Used in marine applications as well as piping, HVAC systems, and fire protection.
Cast Iron
- Excellent strength and durability.
- Used in industrial applications involving high-pressure and abrasive fluids.
- For applications such as chemical plants, power generation, water treatment and wastewater management.
PVC and CPVC
- Lightweight and affordable materials with good chemical resistance.
- Suitable for water treatment, irrigation systems, and residential plumbing.
Factors to consider when selecting ball valve housing materials
- Fluid Compatibility
The first and most important consideration is the compatibility of the housing material with the fluid flowing through the valve. Different fluids may have different chemical compositions, corrosive properties, and temperature ranges. It is critical to select a housing material that will resist the corrosion, erosion, and chemical attack of a specific fluid.
- Temperature and pressure
High temperatures and pressures can affect the mechanical properties and integrity of the enclosure material. It is critical to select enclosure materials that can withstand the expected temperature and pressure range without deformation, cracking, or failure. Materials such as stainless steel and high-performance alloys are often the materials of choice for high-temperature and high-pressure applications.
- Mechanical Strength and Durability
The enclosure material should have sufficient mechanical strength and durability to withstand the operational requirements of the application. It should be able to handle frequent opening and closing cycles without wear or premature failure. In addition, factors such as vibration, shock and external forces should be considered when selecting a robust enclosure material. Steel alloys and materials with high tensile strength are usually selected because of their excellent mechanical properties.
- Environmental factors
Factors such as humidity, moisture, UV exposure, and outdoor elements can affect the performance and life of enclosure materials. For outdoor or corrosive environments, materials with high weather resistance, such as stainless steel or corrosion-resistant alloys, are often recommended.
- Cost
Cost is an important consideration when selecting a housing material for a ball valve. Different materials have different price tags, and the budget allocated to the valve will influence the choice of material. However, it is important not to compromise on quality and performance simply because of cost. Finding a balance between cost-effectiveness and the desired material performance is key.
The advantages of ball valves
- Easy to operate: The ball valve is simple and intuitive to operate, just turn the valve handle or stem a quarter turn to open or close the valve.
- Very low-pressure drop: The flow through is almost unlimited.
- Fast Acting: The valve can be started quickly, it only needs to turn 1/4 turn.
- Cheap: The ball valve itself is relatively low price, low maintenance cost, and no need for lubrication.
- Excellent sealing: The ball and seat design provides a tight seal, minimizing leakage and ensuring reliable shutoff.
- Durability: The ball valve is made of sturdy materials such as stainless steel, brass, or bronze, providing excellent corrosion and wear resistance to ensure a long service life.
Disadvantages of ball valves
- No flow throttling/Regulating: If we want to throttle the flow through the valve, then the only flow through the valve is the gap between the valve flap and the valve seat. Very high-velocity flow at this point will damage the valve flap or seat and may result in the valve no longer seating properly.
- Not for high temp Applications: Seats are usually made of resilient materials, and if used in high-temperature applications, the seat will experience unrecoverable plastic deformation.
Application Industries
Ball valves are used in a wide range of industries and environments, including:
- Industrial: They are used in pipelines, process control systems, and manufacturing plants where precise flow control and reliable shutoff are critical.
- Oil and gas industry: Ball valves play a critical role in upstream, midstream, and downstream operations, handling a variety of fluids and providing fast shutoff in emergency situations.
- Petrochemical and chemical plants: These valves are used to control the flow of chemicals, gases, and hazardous materials, ensuring safety and efficiency.
- Residential and commercial plumbing: Because of their durability and ease of operation, ball valves are commonly used in water systems, irrigation, and HVAC applications.
Summary
This article introduces the ball valve, explains what it is, and discusses its types, how it works, and how to choose the right housing material. To learn more about ball valves, contact an Easiahome representative.
