What are single-piece, two-piece, three-piece, and integrated valve bodies?

Classified by the valve body, if the valve body is a single unit, it is called single-piece; by the same logic

It mainly refers to the structure of the valve body. In simple terms, a one-piece design means that the valve body is a single unit that cannot be separated; a two-piece design means that the valve body can be divided into two parts, usually held together by bolts; while a three-piece design allows the valve body to be split into three parts. If you have any questions, feel free to leave a message on QQ3378677; I have the schematic diagram.

It refers to the structure of the valve; a two-piece valve means that it is assembled from two parts, while a three-piece valve means it is assembled from three parts. In most applications, the 2-piece type is used, as it has fewer components and fewer sealing points, making it more reliable. However, it’s important to note that during installation, the valve body should be placed on the upstream side while the valve cover is installed on the downstream side (although the ball valve itself doesn’t have any orientation requirements). The advantage of this arrangement is that if there are problems with the seal between the body and the cover, the leak can be prevented by closing the valve. If space for installation is limited, then the 3-piece type is preferable, as its components can be installed in stages: first, two valve covers can be installed, followed by the middle sections (valve body, ball, stem, ball seat, external seal, packing, gland, etc.), and finally the pneumatic or electric actuator. Since the components are installed in stages, less space is required for operation, which makes it particularly suitable for use in spaces that are tight, such as trains and ships. Additionally, if flange mounting is used, the 2-piece type is better; whereas if welding is used, the 3-piece type is preferable.