5 features about fixed ball valve that you have to know

Ball valve is widely used in the field of food, medicine, petroleum, chemical, natural gas, iron and steel, environmental protection, paper and other transfer line medium cutting or circulation. It is the type which has a sphere with the fixed shaft, the fixed shaft are connected together by the two sections with the ball bearing; when it is closed, and together with the function of the medium pressure, the ball will not produce displacement.

Shafts are connected together with the ball, the upper and lower shaft is equipped with rolling bearings or sliding bearings, in order to reduce the open and close when the journal of the frictional force, and to reduce the operating torque. Therefore, the fixed ball valve is suitable for high pressure and large diameter valves. Fixed type ball valve usually are equipped with the activities of the valve seat ring, which can produce a displacement under the action of the pressure of the media, and the seal ring is pressed tightly on the sphere, so as to ensure the sealing performance of the valve.

The features of Fixed ball valve are listed as follows:

1. labor-saving operation: the ball sphere is supported by fluctuation of bearings up and down, which reduces friction and eliminates the inlet pressure promote sphere and sealing seat form the great seal load caused by excessive torque.

2. Reliable sealing property: PTFE unisexual material sealing ring is embedded in stainless steel seat, and the metal seat end is equipped with spring which guarantee enough pre-stressing force of seals, so that the valve continues to ensure good sealing performance under the action of spring, even though the sealing surface wears out during using process.

3. Fire resisting structure: in order to prevent the sudden heat or fire appearance which will lead to PTFE ring burning or large leakage to encourage the fire, there are fire rings set in the place between ball sphere and valve. If the ring burned, the seat ring is rapidly put to the sphere under the force of spring, and forms the metal to metal seal, so as to have a certain degree of sealing effect.

4. Automatic relief function: when the medium abnormal pressure stagnated in the valve mid-plane rises to more than the spring preliminary force, the seat back from sphere to achieve automatic relief effect.

5. Drain line: drainage hole is set both on the upper and lower side of the ball body, which can check whether the valve seat leakage occurs, in the work, when the valve is in fully open or seated, after uninstalling mid-plane pressure, it can directly replace the packing, as well as discharge mid-plane retentate to reduce the pollution of media.

China’s Valves Procurement was expected to surpass US By 10% in 2012

Although the world economy is in crisis, the valve market in Asia remains to grow, but it shows austerity in Europe and the United States. 

Large public-held valve company has a small market share in Asia. This has led some analysts to underestimate the total world market. The small valve company’s sales growth in Asia is more than or offset the reduction in sales of large international companies. Asian markets benefit a lot from China to implement the package plan, especially in the field of domestic water. The power industry in Asia is also influential. Global valve market which includes magnetic valve, fixed ball valves, gate valves, plug valves, and other types will reach $ 54 billion in 2012.

The "World Market" (World Markets) Published by McIlvaine Company claims that in 2012, China's valve market is larger than 10% of the U.S. market, which is four times that of the Japanese market. Buyers’ purchasing amount will amount to $ 2.4 billion. In 2012, the top three buyers in the top ten list, and the top six in the top twenty list will all from Asia.

Ball valves and magnetic valve are mainly used for cutting, distribution and change of the medium flow direction in the line and it is widely used in recent years. Fixed ball valve is the type which has a sphere with the fixed shaft, the fixed shaft are connected together by the two sections with the ball bearing; when it is closed, and together with the function of the medium pressure, the ball will not produce displacement. Shafts are connected together with the ball, the upper and lower shaft is equipped with rolling bearings or sliding bearings, in order to reduce the open and close when the journal of the frictional force, and to reduce the operating torque. Therefore, the fixed ball valve and magnetic valve is suitable for high pressure and large diameter valves.

Fixed ball valves usually are equipped with the activities of the valve seat ring, which can produce a displacement under the action of the pressure of the media, and the seal ring is pressed tightly on the sphere, so as to ensure the sealing performance of the valve. Another type of fixed ball valve suitable for high pressure and large diameter is the valve seals, which mean to pressure special grease between the two sealing surfaces to form a layer of film, which not only enhances sealing performance, but also reduces operating torque.

Difference between Fixed Ball Valve and Floating Ball Valve

Ball valve is evolved by cock valve. It has the same rotate 90 degrees mention action, and the difference is that its cock body is sphere, and has circular through hole or channel through its axis. Ball valve only needs to rotate 90 degrees with the operation and small rotation moment can shut tight. Completely equal body cavity for medium provides very small resistance and straight-flow passage. 

Recently, ball valves are designed to make it has the throttle and control flow with. The main characteristics of ball valve is that its structure is compact, it is easy to operate and maintain, and it can be applicable to some working medium such as water, solvent, acid and gas; it is also suitable for poor working conditions of medium, such as oxygen, hydrogen peroxide, methane and ethylene, etc. Ball valve body can be whole or combined type.

There are mainly two types of ball valve– fixed ball valve and floating ball valve, so what’s the difference between the two?

The sphere of floating ball valves is floating, under the action of medium pressure, the ball physically produces certain displacement and presses in the outlet seals, in order to ensure outlet seal, and it belongs to the single forced seal.

Fixed ball valve is fixed, has a sphere with the fixed shaft, the fixed shaft are connected together by the two sections with the ball bearing; when it is closed, and together with the function of the medium pressure, the ball will not produce displacement. Therefore, in the design of this kind of product, there must be enough pre-stressing force between the two seals so as to guarantee leakproofness. It belongs to the double forced seal.

The design of floating ball valve should consider whether the seal material can withstand sphere medium action load. Because the load when sphere under medium are all passed to outlet seals, therefore, the floating ball structure is widely used in low pressure ball valve. In addition, the design should also consider that large diameter ball valve needs bigger moment during operation process.

As for the fixed ball valve, there are shafts connected together with the ball, the upper and lower shaft is equipped with rolling bearings or sliding bearings, in order to reduce the open and close when the journal of the frictional force, and to reduce the operating torque. Therefore, the fixed ball valve is suitable for high pressure and large diameter valves.