By Carson Hu

With competitive price and timely delivery, Xiangyu sincerely hope to be your supplier and partner.

&#;

October 24,

Right now, there are over 3,000 facilities on the Outer Continental Shelf involved in the collection and treatment of oil and gas. These oils and gases are collected from wells -- a process that's performed using certain types of high pressure valves. Of course, different types of American ball valves offer different results and it's crucial that the right projects are executed with the right types of valves. Quite often, the types of valves being used are ball valves, sometimes referred to as pig ball valves or pig vales (as they are used in conjunction with pipeline pigging systems). Before sourcing and investing in valves, it is important to understand the degree to which these valves may differ from one another. Let's delve into some of the defining characteristics of ball valve types. Ball Valve Body Styles Before getting into the exact types of ball valves that are available at the moment, it's important to remember that there are actually four separate types of body styles. These include the single body, split body, top entry, and welded styles. The styles of ball valves available differ from the types of ball valves available. This means that there are number of potential variations that you can see in ball valves. The great thing about this variety is that it means that there is more potential applicability in ball valves than there would be otherwise. Full Port Ball Valves: Turning to the different body types of ball valves, we can first look at the full port ball valve. A full port ball valve is defined by the fact that it has an oversized ball. The oversized ball has a purpose -- it is the same size as the pipeline. This means that there will be less potential friction less than there would be if the ball wasn't the same size as the pipeline, and the flow involved is unrestricted. The valve is larger as well. Standard Port Valves: As their name suggests, standard port valve are quite usual. This means they're less expensive than some alternatives. This type of valve has a smaller ball, and therefore the valve itself is smaller as well. The flow going through the pipe will in turn be smaller and will typically be about one pipe size smaller than the valve's pipe size. This makes it more restricted. The V Port Ball Valve: The V port ball valve is named after its V-shaped seat. What this means is that the orifice through which the product flows can be more easily opened and closed to change its direction. While many like this idea, the construction of this type of valve means that it can't be used just anywhere. It typically needs to be utilized in a more secure site. When the valve is opened, it is usually opened at the "small end" first, which helps stabilize the flow control. Trunnion Ball Valve: Then there is the trunnion ball valve, which doesn't exactly give much away through its name. This type of valve will actually anchor the valve at the top and the bottom through a particular mechanism. This would be applied on larger and more high pressure valves. While this type of valve isn't going to fit everyone's needs, it can definitely be used for particularly high pressure projects. Manually Operated Valves: Finally, these types of valves can be closed more quickly than their counterparts. Though this is an advantage in some cases, it also means that there can be a risk of a water hammer. These can include an actuator, which can be pneumatically or motor operated, which will in turn be used for on/off flow control. The valve will also have a positioner, which transforms the control signal into an actuator position. The flexibility of this type of valve is certainly an advantage to most projects. Now that you're more familiar with the styles and types of ball valves, you'll be in a better position to make decisions that will support your needs. For more information, please contact us today.

Trunnion Ball Valve - How They Work

Figure 1: Free floating ball valve (left) and a trunnion mounted ball valve (right)

Trunnion ball valves are quarter-turn valves used to control the flow of media in a pipeline. Unlike the more common "free floating" ball valve design, trunnion ball valves have a unique configuration. In a trunnion ball valve, the ball is secured by connecting it to the stem on one side and a shaft called the trunnion on the other, ensuring the ball remains firmly in place. In contrast, a floating ball valve connects the ball only to the stem, allowing it to "float." This distinction is illustrated in Figure 1, highlighted by a red box.

Trunnion ball valves have many different advantages over free floating valves, they are suitable for low, and high-pressure applications, and offer lower operational costs then free floating ball valves.

Trunnion ball valve advantages

High pressure applications

For high pressure applications, a trunnion ball valve is the ideal ball valve design type. In the floating ball valves the ball has some freedom of movement. During use, the ball floats slightly downstream against the seat ring and creates a sealing only on one side of the valve. In addition, the torque on the stem is also increased.

This is the point where the trunnion design offers a solution. In the trunnion valve design, the ball is not floating as it is connected to the trunnion. This is advantageous since it will maintain a proper seal on both sides and there is no added torque to the stem. Therefore, for higher pressure applications a trunnion ball valve will provide better sealing and require less torque to turn.

Figure 2: A cross section of a trunnion ball valve, clearly showing the trunnion (A), and spring mounted seats (B)

If you want to learn more, please visit our website Trunnion Vs Floating Ball Valve.

Spring-loaded seats

Trunnion mounted ball valves are fitted with spring loaded seats. In a floating ball valve the pressure forces the ball against the seats, which creates a seal. Unfortunately the ball valve will need high pressure to create an effective seal, which would render them ineffective in low pressure systems.

Trunnion mounted ball valves are effective in both low and high pressure situations. In low or no-pressure situations the spring-loaded seats will create a seal, while also working for high pressure applications.

Lower operational costs

A trunnion mounted ball valve provides lower operational costs due to the fact that any additional pressure on the valve is absorbed by the trunnion and the stem. This leads to a lower operating torque, and subsequently eliminates the need for a large actuator.

To learn more about making the right selection of ball valve for your application, read our ball valve selection technical article!

Trunnion mounted ball valve weight

A trunnion ball valve is designed by API608 or API 6D and complies with several other industry standards. API 6D gives basic design, dimensions, and testing standards for the trunnion valve. The API 6D standard also gives the standard weights of trunnion ball valves corresponding to different bore sizes and body dimensions.

Trunnion double block and bleed (dbb) ball valves

Double block and bleed (DBB) is the process of shutting a pipe section on both sides of the valve rather than just one. Therefore a trunnion ball valve can block both the upstream and downstream sides of the working area and then vent (bleed) any pressure that remains in the piping and valve. A double block and bleed (DBB) is often used for stricter isolation of process fluid from other equipment. It usually consists of two trunnion ball valves that act as block valves and a bleed valve (usually ball or needle valve) to a safe location, consistent with local environmental regulations.

A DBB valve is a side-entry ball valve designed for downstream, midstream, and upstream gas and oil applications with either a welded or bolted body. The valve has two seats, each providing a seal against pressure separately. One seat seals the fluid from upstream, and the other seat seals the fluid from downstream. For a DBB trunnion mounted ball valve, when the valve is in the closed position, and the fluid comes from upstream, it pushes the seat against the ball to release the sealing.

When the pipeline is under pressure, the trunnion ball valve is closed. The fluid remains trapped within the ball, which creates a resultant pressure in the ball. The pressure within the ball rises when the temperature in the ball becomes higher. It is necessary to vent/bleed the pressure when the pressure in the ball becomes high enough. For a trunnion ball valve with a bleed function, the pressure in the ball pushes the seat back as the spring behind the seat compresses, and there is vent/bleeding between the sealing surfaces. According to API 6D specifications, the venting/bleeding is required at a pressure of less than 1.33 times the design pressure rating for the ball valves. However, several critical projects need to vent at a pressure less than 1.1 times the originally designed pressure.

Learn more about ball valves in our extensive ball valve guide.

Figure 3: Double block and bleed valve

For more China 3 Way Ball Valve Supplierinformation, please contact us. We will provide professional answers.