Ball Valves: Types and Materials



Ball valves are straight-through valves that require only a quarter-turn to open or close. Ball valves have a circular closure element that is placed into a seat within the valve. This design permits uniform sealing stress within the valve. Ball valves are named for the ball closing element, which rotates to open and close the valve. Because of the even sealing stress, ball valves are a great option when a tight seal is needed when the valve is closed. They are able to transport matter in all three states (solid, liquid, and gas) as well as slurries (liquids with suspended solids).

5 Types of Ball Valves

There are 5 main types of ball valves that can be used to perform a number of different tasks. Each type of ball valve has different advantages, which may make one type of ball valve more desirable than another.

1. Full Port

Full port ball valves are designed to have an oversized ball that is equal in diameter size to the inside of the piping present. Because the diameter size of the hole located in the bore of the valve is the same as the rest of the piping, when the valve is open, the flow of material through the valve and out the other side is unrestricted. This is the main advantage of full port ball valves.

Full port ball valves are most commonly used for throttling applications. They are considered to be recovery valves, which can be utilized in various systems with low pressure drops and high flow coefficients. Find the specs of our full-port metal ball valves here.

2. Standard Port

Standard port ball valves differ from full port ball valves in that the size of the hole located within the bore is smaller in diameter than the inside of the piping surrounding the valve. This results in some of the flow of material being reduced. While they are commonly less expensive than other types of valves, standard port valves typically have higher pressure drops than others.

Like full port valves, reduced port valves are recovery valves commonly used in systems with high flow coefficient.

3. V Port

V port ball valves have either a V shaped ball or a V shaped seat. When the valve is moved into the opened position, the bottom section of the V is opened first. This gives better control over the flow of material running through the open valve. This type of ball valve requires higher quality construction than other types of valves, as the fluids running through the valve will be moving at a higher velocity.

V port valves are most commonly utilized in the chemical plants, as well as within the paper and power industries.

4. True Union (Trunnion)

True Union ball valves are different from other types of ball valves in that they are designed to have a pin in place, securing the ball so it does not move. True union valves use a segmented ball which is supported by the valve through the use of two shafts located at opposite ends of the ball. True union ball valves are meant to cause less friction between the parts of the valve.

True union type valves are most commonly used in high velocity systems, which are under higher pressure than standard ball valves could withstand. These ball valves can be removed from piping systems, as needed.

5. Manually Operated

The most common type of ball valve is manually operated, due to its ease of use and simplistic design. There are some valves that are equipped with motors to control flow as well as the opening and closing of the valve. Manual operation of ball valves is typically simple, requiring only a quarter turn to completely close or open the valve, though quick closure of valves poses the danger of water hammer.

Materials for Ball Valves

In addition to coming in a number of designs, ball valves are made of a number of different materials. Certain materials have more desirable characteristics for different uses, so it is important to know the basics of ball valve materials before purchasing anything.

1. PVC

Polyvinyl Chloride, also known as PVC, is one type of plastic commonly used in the production of ball valves. PVC is beneficial for a number of reasons. Primarily, PVC is valued for its flexibility, as opposed to a metal valve. PVC is also smooth, which allows the valve parts to move easily.

2. CPVC

Chlorinated PVC has similar characteristics to PVC. What sets CPVC apart from PVC is that Chlorinated PVC is able to withstand higher temperatures, making it suitable for hot water uses.

3. Bronze and Brass

Brass is a material comprised of both copper and zinc. Bronze is an alloy that contains copper, zinc, tin, and lead. Bronze is an ideal material for valves used in low or medium pressure systems, and is good for more complex castings. Bronze is also corrosion and wear resistant. Brass is similar to bronze in its machinability; however, brass is more economical than bronze (find out more).

4. Iron

Iron is a material most commonly used in steam, water, oil, and gas pipelines. When it comes to making ball valves, iron is a valued material due to the vast range of temperatures and pressures that it can withstand. Iron offers a high performance as a valve material to offset cost.

5. Stainless Steel

Stainless steel is another common material used to make ball valves. Stainless steel has a number of positive characteristics which make it a desirable material, including its durability and its corrosion resistant properties. This material is used in a wide number of systems, including general plant and geochemical systems.

Advantages and Disadvantages of Ball Valves

There are a number of pros and cons when it comes to using ball valves. On one hand, ball valves are very easy to operate, and they have a long service life. They require no extra lubrication and have low production and maintenance costs. Ball valves are able to withstand high pressure, high velocity, and high temperature flows. These characteristics make ball valves common among chlorine manufacturers, in systems on ships, and within fire safety protection services. On the other hand, ball valves are not recommended for use in bioprocessing, pharmaceutical, or food and drink systems because they cannot be easily cleaned, which can potentially lead to contamination.