Advantages Disadvantages and Application Scope of Ball Valve

I. Advantages and disadvantages of ball valve

1. Advantages of Ball Valve:

• ① It has the lowest flow resistance (actually 0);
• ② It can be reliably used in corrosive medium and low boiling point liquid because it can not be stuck during operation (when there is no lubricant);
• ③ In a large range of pressure and temperature, it can achieve complete sealing;
• ④ It can realize quick opening and closing, and the opening and closing time of some structures are only 0.05 ~ 0.1s, so as to ensure that it can be used in the automation system of the test bench. When the valve is opened and closed quickly, there is no impact during operation;
• ⑤ The spherical closing part can be automatically positioned at the boundary position;
• ⑥ The working medium shall be sealed reliably on both sides;
• ⑦ Qhen the valve is fully open and closed, the sealing surface of the ball and the valve seat is isolated from the medium, so the medium passing through the valve at high speed will not cause the erosion of the sealing surface;
• ⑧ It has compact structure and light weight, so it can be considered as the most reasonable valve structure for low temperature medium system;
• ⑨ The valve body is symmetrical, especially the welded valve body structure, which can well bear the stress from the pipeline;
• ⑩ The ball valve with fully welded valve body can be directly buried in the ground, so that the internal parts of the valve are not corroded, and the maximum service life can reach 30 years. It is the most ideal valve for oil and gas pipelines.

2. Disadvantages of Ball Valve:

• ① Because the main sealing ring material of the valve seat is polytetrafluoroethylene, it is inert to almost all chemical substances, and has the comprehensive characteristics of small friction coefficient, stable performance, not easy to aging, wide range of temperature application and excellent sealing performance. But the physical characteristics of PTFE, including high expansion coefficient, sensitivity to cold flow and poor thermal conductivity, require that the design of the valve seat seal must be based on these characteristics. Therefore, when the sealing material becomes hard, the reliability of the seal will be damaged. Moreover, the temperature resistance grade of polytetrafluoroethylene is low, and it can only be used under the condition of less than 180 ℃. Beyond this temperature, the sealing material will age. In consideration of long-term use, it is generally not used at 120 ℃.
• ② Its regulating performance is worse than that of gate valve, especially pneumatic valve (or electric valve).

II. Application scope of ball valve:

Due to the ball valve working principle, it is widely used in petroleum refining, long-distance pipeline, chemical industry, papermaking, pharmaceutical industry, water conservancy, electric power, municipal administration, steel and other industries.

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