The full-port ball valve is also known as a full-bore ball valve. A full-port ball valve is a type of ball valve with a larger body than a standard ball valve. With a larger body, a full-port ball valve houses a larger ball as well as larger openings. Full-port ball valves have their openings the same size as the connected pipe. For instance, a full port ball valve with a 2-inch diameter will need a pipe of 2-inch in diameter. This means that such a full-port ball valve will have a ball hole of 2-inch. A full-port ball valve is advantageous in that it produces less fluid resistance, pressure drop and has less friction when fluid flows. Full-port ball valves are mostly used in applications where cleaning and low fluid resistance are needed and where pressure loss can affect pipe performance. However full port ball valves are expensive relative to other ball valves.

 

Figure: Standard port ball valve compared to a full port ball valve.

 

Components of a full-port ball valve 

Valve housing 

The valve housing is also known as the valve body. This is the component of a full port ball valve used to cover all internal components of the valve. This is one of the most important parts of a full port ball valve as it protects the valve against excess pressure and safety to all internal parts. The valve housing is made of strong materials relative to its application to ensure that the full port ball valve can withstand high temperature and high pressure.

Valve handle 

This is a component used in manual full port ball valves. The handle is the component where the full port ball valve operator applies force to open/close the valve.

Actuator 

An actuator is a component used in automatic full port ball valves. The actuator is used to provide the force needed to open/close the full port ball valve. The actuators used in full port ball valves include hydraulic, pneumatic, and electric actuators. An automated system is used to control the closing/opening of the full port ball valve. However, the use of actuators is necessary for complicated control systems.

Stem or shaft 

A stem or shaft is the component of a full port ball valve used to connect the ball to the handle or actuator. One end of the stem is connected to the actuator or handle while the other end connects to the ball. The stem has O-rings and packing rings used to prevent fluid leakage.

Rotary ball 

This is a ball with a hole at its middle part. The ball is responsible for opening/closing media flow. The ball is connected to the stem so that when the stem is rotated by the actuator or handle, the ball rotates a quarter turn to allow or block fluid flow.

Seats 

The seat is a disc installed between the valve body and the ball. The seats help to provide a seal between the ball and the body.

Packing 

Packing is a seal placed around the stem. It helps to prevent leakage of fluid through the stem.

How does a full port ball valve work? 

A full port ball valve is a ball valve that opens and closes fluid flow using a ball. The ball in a full-port ball valve has a bore at its center. The fluid in a full-port ball valve passes through this bore in the ball. The ball in a full-port ball valve is connected to the handwheel or actuator through the stem. When torque is applied on the handwheel, it is transmitted to the ball via the valve stem. To open a full-port ball valve, the handle is turned a quarter turn that is 90^o. When the handle is rotated 90^o it also rotates the stem and the ball for 90^o. When the ball is rotated for 90^o it makes the ball bore to be in line with the pipeline containing the fluid. The makes the fluid flow through the valve and the full-port ball valve is said to be open. To close a full-port ball valve, the handle is rotated in the opposite direction for 90^o. This makes the valve stem and the ball rotate 90^o. At this stage, the ball bore becomes perpendicular to the pipeline and the fluid cannot flow through the valve. In this state, the full port ball valve is said to be closed.

 

Figure: Open full port ball valve and closed full-port ball valve.

 

Types of full port ball valve 

Two-piece full port ball valve

This is a full port ball valve with two pieces. One-piece consists of the valve body and one end connection and the second piece is fitted into the first piece to hold the trim in place and it also contains the second end connection. Two-piece full port ball valves can be dismantled for inspection, cleaning, repair, and maintenance. However, in a two-piece full port ball valve, the valve must be removed completely from the pipeline to separate the two pieces. The two-piece full port ball valve is used in high-pressure applications, cold and hot domestic water, HVAC, compressed air, low-pressure steam applications among others.

Figure: Two-piece full port ball valve.

 

Three-piece full port ball valve 

A three-piece full port ball valve is a ball valve designed with three pieces that is a body and two end caps. This full port ball valve has three pieces connected using bolts and nuts. A three-piece full port ball valve is designed in a way that makes it easy to remove the center part containing stem, ball, and seats from the piping system. This helps to enhance effective cleaning of deposited solids, replacement of gland packing and seats, polishing scratches on the ball without the need to remove the pipe from the valve body. A three-piece full port ball valve is advantageous in that it can be serviced without the need to remove the whole valve from the piping system. Three-piece full port ball valves are very strong and thus suitable for high pressure and high-temperature applications. However, three-piece full port ball valves are very expensive relative to other valves like globe valve and butterfly valve.

Figure: Three-piece full port ball valve.

Three-way full port ball valve 

A three-way full port ball valve is a ball valve with three ports. This type of full port ball valve uses three ports to serve as a mixing valve or as a diverting valve. A three-way full port ball valve has two configurations that is L shape and the T shape. The L shape of a three-way full port ball valve is used to divert fluid from one port to another port. The T-shaped three-way full port ball valve is used to divert fluid or to mix fluid. When used to mix fluids, a three-way full port ball valve merges two fluid streams from the inlet ports into one stream to flow via the outlet port. T shaped three way ball valve is also used to divert fluid flow from one port into the other two ports.

Flanged full port ball valve 

The flanged full port ball valve is a valve defined by flanged ends where bolts and nuts are used to connect the valve to the pipeline. This type of full port ball valve provides effective control of fluid as it can enhance a bubble-tight seal. One advantage of a flanged full port ball valve is that it can easily be removed from the pipeline for inspection, cleaning, repair, and maintenance. As such, this type of full port ball valve can enhance sanitation as it is easy to clean. It is also economical because when a component fails in a flanged full port ball valve, it can be repaired instead of disposing the whole valve.

Figure: Flanged full port ball valve.

 

Applications of full port ball valve 

• Full port ball valves are used in feed water and cooling water systems.
• They are used in irrigation and water supply systems.
• They are used in pharmaceutical industries.
• Full port ball valves are used in steam power generation.
• These valves are used in food and beverages processing.
• Full port ball valves are used in chemical admixtures and treatment.
• They are used in oil and gas industries.
• Full port ball valves are used in fire-safe systems.

 

Advantages of full port ball valve 

• A full port ball valve offers a bubble-tight seal free from leakage.
• Full port ball valves open and close quickly.
• These valves are light in weight relative to other valves like gate valve.
• Full port ball valves are versatile as they can be used in different applications in different industries.
• Full port ball valves are strong which makes them suitable for use in pressure and high-temperature applications.
• The full port ball valve can use multiple ports suitable for different tasks such as fluid mixing and fluid diversion.
• Full port ball valves are suitable for inspection, cleaning, repair, and maintenance.
• Full port ball valves have low fluid resistance which makes them more efficient.
• These valves have a low-pressure drop.

 

Disadvantages of full port ball valve 

• Full port ball valves are not suitable for throttling applications.
• Full port ball valves are not suitable for applications with solids because they tend to cause wear, leakage, and valve failure.
• Full port ball valves are expensive relative to other valves.

 

Troubleshooting full port ball valves 

Internal leakage 

• Leakage through the ball. Clogged particles. Clean the particles blocking the ball.
• The stem or shaft is broken. Remove end connection and check rotation of the ball while operating the valve. Repair or replace the stem as necessary.
• Damaged seat. Replace the seat.
• Debris on the seat. Clean the debris.
• Damaged, or displaced seat O-ring. Replace the seat O-ring accordingly.
• Damaged ball. Replace the ball.

The full port ball valve difficult to open/close

• Internal obstructions due to sediment build-up. Remove the full port ball valve and check for sediment build-up and clean the sediments. Check for valve compatibility with the media being worked on.
• Over tightened handle. Loosen the handle slightly.
• Chemical attack on the full port ball valve. Check for an attack such as distortion, etching, peeling, or bleaching of surfaces. Ensure the valve is compatible with the fluid.
• Broken handle. Replace the handle.
• Handle stripped. This could be due to excess exposure to sunlight or high temperature softening the handle. Shield the valve from sunlight. Replace the handle if necessary.
• Broken stem. Replace the stem/shaft.

 

Summary 

A full port ball valve is a type of ball valve in which the diameter of the ball bore is equal to the diameter of the pipe. In this case, for example, a 2-inch diameter ball bore in a full port ball valve will be connected to a pipe with a diameter of 2 inches. Full port ball valves help to reduce fluid flow resistance and pressure drop because the flow is almost straight unlike in other valves such as standard ball valves or reduced bore ball valves. Full port ball valves work by using a ball with a hole at its middle part. The bore is meant to allow fluid flow when the full port valve is open. When a full port ball valve is open, the ball bore is collinear to the pipeline. When the full port ball valve is in a closed state, the ball bore is oriented perpendicular to the fluid flow thus blocking fluid flow.

There are various types of full port ball valves which include three-piece full port ball valve, two-piece full port ball valve, three-way full port ball valve, flanged full port ball valve among others. Full port ball valves are used in various applications among them power generation, feedwater and cooling water systems, oil and gas, irrigation, and chemical industry among others. Full port ball valves are advantageous in various ways such as they can be inspected, cleaned, and repaired, they are versatile, durable, operate quickly, have strong bodies, suitable for high-pressure applications, they are energy efficient among others.