The classification and characteristic analysis of ball valve

2024-07-17 Read：478

Ball valve classification and characteristics:

1, floating ball valve: the ball of the valve is floating, under the action of medium pressure, the ball can produce a certain displacement and tight pressure on the sealing surface of the outlet to ensure that the outlet is sealed. The structure of the floating ball valve is simple and the sealing is good, but the load of the ball bearing the working medium is all passed to the outlet sealing ring, so it is necessary to consider whether the sealing ring material can withstand the working load of the ball medium, and the ball may be offset when it is subjected to higher pressure impact. This structure is generally used for medium and low pressure ball valves.

2. Fixed ball valve: The ball of the ball valve is fixed and does not move after pressure. Fixed ball valves are equipped with floating seat, under the pressure of the medium, the seat is moved, so that the sealing ring is firmly pressed on the ball to ensure sealing. Bearings are usually installed on the upper and lower shafts of the ball, and the operation torque is small, 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, in recent years, the oil seal ball valve has appeared, both in the sealing surface between the pressure injection of special lubricating oil to form a layer of oil film, (recommended by the valve manufacturer: China Guowei Valve Manufacturing Co., LTD.) that is to enhance the sealing, but also reduce the operating torque, more suitable for high-pressure large-caliber ball valves.


3, elastic ball valve (that is, track ball valve): the ball of the ball valve is elastic. The ball and the seat sealing ring are made of metal materials, the specific pressure of the seal is very large, and the pressure of the medium itself can not meet the requirements of the seal, and external forces must be applied. This valve is suitable for high temperature and high pressure media. An elastic sphere is an elastic groove opened at the lower end of the inner wall of the sphere to obtain elasticity. When the channel is closed, use the wedge head of the stem to expand the ball and press the seat to seal. The wedge head is loosened before the ball is turned, and the ball is then restored to its original shape, so that there is a small gap between the ball and the seat, which can reduce the friction and operating torque of the sealing surface.

4, V-type ball valve: This ball valve is a fixed ball valve, but also a single seat sealed ball valve, the adjustment performance is the best in the ball valve, the flow characteristic is equal to the percentage, adjustable ratio of 100:1. It has a shear effect between the V-shaped incision and the metal seat, especially suitable for media containing fibers, small solid particles, slurry and so on.

5, three-way ball valve: three-way ball valve has T type and L type. The T type can make the three orthogonal pipes interconnect with each other and cut off the third channel, which plays the role of shunt and confluence. The L-type can only connect the two orthogonal pipelines, and cannot maintain the mutual connectivity of the third pipeline at the same time, and only plays the role of distribution.