1. Working principle of stainless steel ball valve
Stainless steel ball valve is a new type of valve that is widely used. The working principle of stainless steel ball valve is to rotate the valve core to make the valve unobstructed or blocked. Stainless steel ball valves are easy to switch, small in size, can be made into large diameters, have reliable sealing, simple structure, and easy maintenance. The sealing surface and spherical surface are always in a closed state and are not easily eroded by the medium. They are widely used in various industries.
The stainless steel ball valve only needs to be rotated 90 degrees and a small rotational torque to close tightly. The completely equal valve body cavity provides a straight flow path with little resistance for the medium. The main feature of the ball valve is that it has a compact structure and is easy to operate and maintain. Stainless steel ball valves can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media. The ball valve body can be integral or combined.
2. Classification of stainless steel ball valves
Classification according to power:
Stainless steel pneumatic ball valve, stainless steel electric ball valve, stainless steel manual ball valve.
Classification according to material:
304 stainless steel ball valve, 316L stainless steel ball valve, 321 stainless steel ball valve, etc.
Classified according to structure:
(1) Floating ball valve - the ball of the ball valve is floating. Under the action of medium pressure, the ball can produce a certain displacement and press against the sealing surface of the outlet end to ensure the sealing of the outlet end. The floating ball valve has a simple structure and good sealing performance, but all the load of the working medium on the ball is transferred to the outlet sealing ring. Therefore, it is necessary to consider whether the sealing ring material can withstand the working load of the ball medium. This structure is widely used in medium and low pressure ball valves.
(2) Fixed ball valve: The ball of the ball valve is fixed and does not move after being pressurized. Fixed ball and ball valves all have floating valve seats. After being subjected to medium pressure, the valve seat moves, causing the sealing ring to press tightly on the ball to ensure sealing. Bearings are usually installed on the upper and lower shafts of the ball, with small operating torque, and are 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, the oil-sealed ball valve has emerged. Special lubricating oil is injected between the sealing surfaces to form an oil film, which not only enhances the sealing, but also reduces the operating torque and is more suitable. High pressure large diameter ball valve.
(3) Elastic ball valve: The ball of the ball valve is elastic. The ball and valve seat sealing ring are both 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 kind of valve is suitable for high temperature and high pressure media. The elastic sphere obtains elasticity by opening an elastic groove at the lower end of the inner wall of the sphere. When closing the channel, use the wedge-shaped head of the valve stem to expand the ball and compress the valve seat to achieve a seal. Loosen the wedge-shaped head before turning the ball, and the ball will return to its original shape, leaving a small gap between the ball and the valve seat, which can reduce friction on the sealing surface and operating torque.
Classification according to channel location:
Ball valves can be divided into straight-through stainless steel ball valves, three-way stainless steel ball valves and right-angle stainless steel ball valves according to their channel positions. Among them, the three-way stainless steel ball valves include T-shaped three-way stainless steel ball valve and L-shaped three-way stainless steel ball valve. T-shaped three-way stainless steel ball valve can connect three orthogonal pipelines with each other and cut off the third channel to divert and merge flows. The L-shaped three-way stainless steel ball valve can only connect two mutually orthogonal pipelines, and cannot maintain the interconnection of the third pipeline at the same time. It only plays a distribution role.
Classified according to composition:
One-piece stainless steel ball valve, two-piece stainless steel ball valve, three-piece stainless steel ball valve.