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Ball valve's application occasions and structural characteristics

   Ball valve with a round hole in the ball as the opening and closing parts, the ball with the stem rotation, to achieve the opening and closing action of the valve. Ball valve in the pipeline is mainly used to cut off, distribution and change the direction of media flow, designed as a V-shaped opening of the ball valve also has a good flow regulation function. Ball valves can be closed tightly only with the operation of rotating 90 degrees and a small turning torque. Ball valves not only simple structure, good sealing performance, but also in a certain nominal throughput range of small size, light weight, less material consumption, small installation size, and driving torque is small, easy to operate, easy to achieve rapid opening and closing, easy to operate and maintain, for water, solvents, acids and natural gas and other general working media, but also for the working conditions of the harsh media, such as oxygen, hydrogen peroxide, methane and ethylene. The ball valve body can be one piece. The ball valve body can be integral or combined.

    Ball valve is one of the fastest growing valve varieties in recent decades. Especially in industrially developed countries, the use of ball valves is very extensive, the use of varieties and the number of continues to expand, and to high temperature, high pressure, larger caliber, high sealing, long life, excellent regulating performance, as well as a multi-functional direction of the development of the valve, its reliability and other performance indicators have reached a high level, and has partially replaced the gate valve, globe valve, throttle valve. It has been widely used in aerospace, petrochemical, long-distance pipeline, light industry, food, construction and many other aspects. Ball valves have many outstanding advantages compared with other valves.

    The main features of the ball valve are as follows:

    (1) Ball valve fluid resistance is small, with the lowest flow resistance (practically zero)

   Ball valves are generally available in both reduced and non-reduced channel configurations. No matter what kind of structure, the flow resistance coefficient of the ball valve is relatively small. In particular, the so-called full-flow type, that is, without reducing the diameter of the ball valve, because of its channel diameter is equal to the inner diameter of the pipeline, the local resistance loss is only the friction resistance of the same length of the pipeline, i.e., in all the valves, the flow resistance of this type of ball valves is the smallest.

    (2) The ball valve opens and closes quickly and easily.

As the ball valve in general only need to handle turn 90 ° to complete the full open or full closed action, it is easy to achieve rapid opening and closing. When opening and closing the valve quickly, the operation is shockless.

    (3) Good sealing performance of ball valve.

At present, the vast majority of ball valve seat is made of PTFE and other elastic materials, metal and non-metallic materials composed of sealing vice, usually called soft seal. Generally speaking, the sealing of the soft seal is easy to ensure, and the sealing surface machining accuracy and surface roughness requirements are not very high.

     (4) Long service life of ball valves.

    As PTFE has good self-lubrication, the friction and wear with the ball is small, and due to the improvement of the ball processing technology, so that the roughness is reduced, thus improving the service life of the ball valve.

    (5) The high reliability of ball valves is mainly due to:

    ①The ball and the valve seat generally to the sealing vice will not occur abrasion, sharp wear and other faults, in the work will not be stuck (in the absence of lubricant), so it can be reliably used in corrosive media and low boiling point liquids;

    ②Internally mounted stem structure eliminates the accidental danger that the stem may fly out due to loosening of the packing gland under fluid pressure;

    ③The ball valve with anti-static and fire-resistant structure is suitable for pipelines conveying oil, natural gas and gas.

    (6) The channel in the valve body is flat and smooth, more suitable for conveying viscous fluids, slurries and solid particles. Slurry, and solid particles.

   (7) The ball-type closure elements are capable of automatic positioning in position and of withstanding high differential pressure during closure.

   (8) A complete bi-directional seal can be achieved over a wide range of pressures and temperatures.

     (9) During full opening and closing, the sealing surfaces of the ball and seat are isolated from the medium, so that the medium passing through the valve at high velocity will not cause erosion of the sealing surfaces.

    (10) Compact structure, light weight, can be considered as the most reasonable valve structure for low-temperature media system.

    (11) The symmetry of the valve body, especially the welded body construction, provides good resistance to stresses from the pipeline.

     (12) The ball valve with fully welded body can be buried directly in the ground, so that the inner parts of the valve are not subject to erosion, and the maximum service life can be up to 30 years, which is the most ideal valve for oil and gas pipelines.