1、 Structure and characteristics of one piece ball valve
One piece ball valve is called a one piece ball valve because the valve body adopts an integral structure. Its appearance is small and its weight is light. The ball core, valve seat, and valve stem are installed from the flow channel on one side of the valve body. Due to limitations in the flow channel size of the valve body, the full diameter ball core cannot be installed inside the valve body, so the flow channel of the one piece ball valve ball core is reduced. The circulation capacity is subject to certain limitations. There is a certain cost advantage. Mainly used for low-pressure pipelines.
One piece ball valve has threaded connections, flange connections, and wafer connections. Threads typically use 55 ° taper pipe threads to achieve better sealing performance. The installation of flange connections is relatively convenient. The clamp connection structure has a short length and can be installed on compact space pipelines.
The valve is made of WCB cast steel, stainless steel CF8, CF8M, and other materials.
One piece threaded ball valve is mostly used in low-pressure pipelines due to the shallower valve stem packing chamber and less sealing packing added.
The one piece flange ball valve is made into a high-temperature sewage ball valve, which can effectively prevent media leakage from the valve body and avoid the risk of media leakage between the two piece and three piece ball valves. Can be used for steam and heat transfer oil media. It can also be made into an insulated ball valve to transport easily crystallized and solidified media. The insulated shell is filled with hot water, steam, and other thermal media to keep the ball valve insulated.

2、 Structure and characteristics of two-piece ball valve

The valve body of a two piece ball valve is composed of two parts: the main valve body and the auxiliary valve body, so it is called a two piece ball valve. It is a commonly used ball valve. After the ball core, valve seat, and valve stem are installed in the main valve body, the auxiliary valve body is connected to the main valve body through threads or bolts. The ball core flow channel has a full diameter size, low flow resistance, and high flow capacity.
Two piece ball valves also have internal threaded connections, external threaded connections, and internal and external threaded connections. The thread usually adopts 55 ° taper pipe thread, which has good sealing performance. Two piece flange connected ball valves are widely used.
3、 Structure and Characteristics of Three Piece Ball Valve
The valve body of a three piece ball valve is composed of one main valve body and two auxiliary valve bodies, so it is called a three piece ball valve. After the ball core and valve stem are installed in the main valve body, the auxiliary valve body is installed in the valve seat, and the main and auxiliary valve bodies are connected together through bolts. The ball core flow channel is also of full bore size.
The three piece ball valve also has internal thread connection, external thread connection, and the internal thread usually adopts 55 ° cone pipe thread, which has good sealing performance. External thread with welded joint, can be welded with pipeline. It is more convenient to disassemble and assemble during maintenance, avoiding the need for separate unions for internal threaded connections.
Butt welding and socket welding can also be used for connection, and extended connecting pipe welding can be used to avoid high-temperature damage to the valve seat sealing ring and valve stem packing during welding, reducing installation difficulty.