The basic classification of ball valve

ball valve

1. Floating ball valve
The main structural features of the floating ball valve are:
(1) The valve is equipped with open and closed position indications;
(2) Locking device;
(3) Anti-flying structure of valve stem;
(4) Anti-static device;
(5) Fireproof structure;
(6) Unique valve seat sealing structure;
(7) The middle flange (the connecting part of the valve body and the left body) has no leakage structure.
Floating ball valves are divided into ordinary carbon steel series (WCB&A105), stainless steel series (304,316), low temperature steel series (LCB, LCC), sulfur-resistant series, etc. based on the shell material according to different usage requirements.
The ball of the floating ball valve is floating. Under the action of the medium pressure, the ball can produce a certain displacement and press tightly on the sealing surface of the outlet end to ensure that the outlet end is sealed. The floating ball valve has a simple structure and good sealing performance, but the load of the working medium on the sphere is all transmitted to the outlet sealing ring. Therefore, it is necessary to consider whether the material of the sealing ring can withstand the working load of the sphere medium. When subjected to a higher pressure impact , The sphere may shift. This structure is generally used for medium and low pressure ball valves. Floating ball valve is suitable for general industrial use.

2. Fixed ball valve
The ball of the ball valve is fixed and does not move after being pressed. The fixed ball valve is equipped with a floating valve seat. After the pressure of the medium, the valve seat moves, so that the sealing ring is pressed tightly on the ball to ensure sealing. Bearings are usually installed on the upper and lower shafts of the sphere, and the operating torque is small, which is suitable for high-pressure and large-diameter valves.
In order to reduce the operating torque of the ball valve and increase the reliability of the seal, oil-sealed ball valves have appeared in recent years, that is, special lubricating oil is injected between the sealing surfaces to form an oil film, which not only enhances the sealing performance, but also reduces the operating torque. , It is more suitable for high-pressure and large-caliber ball valves.

3. Elastic ball valve (or track ball valve)
The ball of the orbital ball valve is elastic. Both the ball and the valve seat sealing ring are made of metal materials, and the sealing specific pressure is very large. The pressure of the medium itself cannot meet the sealing requirements, and external force must be applied. This valve is suitable for high temperature and high pressure media.
The elastic sphere is made by opening an elastic groove on the lower end of the inner wall of the sphere to obtain elasticity. When closing the passage, use the wedge-shaped head of the valve stem to expand the ball and press the valve seat to seal. Loosen the wedge-shaped head before rotating the ball, and the ball will return to its original shape, so that there is a small gap between the ball and the valve seat, which can reduce the friction of the sealing surface and the operating torque.

4. V-shaped ball valve
The V-shaped ball valve is a fixed ball valve and also a single-seat sealed ball valve. The adjustment performance is the best among ball valves. The flow characteristics are equal percentages and the adjustable ratio is up to 100:1. It has a shearing effect between its V-shaped incision and the metal valve seat, which is especially suitable for media containing fibers, small solid particles, slurry and other media.

5. Three-way ball valve
Three-way ball valve has T type and L type. The T type can connect three orthogonal pipelines with each other and cut off the third channel, which plays a role of diverting and merging. The L-shape can only connect two orthogonal pipes, and cannot maintain the third pipe to communicate with each other at the same time. It only plays a role of distribution.
Features
(1) The three-way ball valve adopts an integrated structure in structure, and the four-sided valve seat adopts a sealed type, with few flange connections, high reliability, and a lightweight design.
(2) The three-way ball core is divided into T type and L type, with long service life, large flow capacity and low resistance.
(3) The ball valve is divided into two types, single-acting and double-acting according to the action type. The characteristic of the single-acting type is that once the power source fails, the ball valve will be in the state required by the control system.