3, ball valve: is evolved from the plug valve, its opening and closing parts is a ball, using the ball around the stem axis rotation 90° to realize the purpose of opening and closing. Ball valve is mainly used to cut off, distribute and change the direction of medium flow in the pipeline. The ball valve with v-shaped opening also has a good flow regulation function.
Advantages:
(1) With low flow resistance (actually 0);
② Because it will not be stuck at work (in the absence of lubricant), it can be reliably applied to corrosive media and low boiling point liquid;
In a wide range of pressure and temperature, can achieve complete sealing;
④ It can realize fast opening and closing, and the opening and closing time of some structures is only 0.05-0.1s to ensure that it can be used in the automation system of the test bed. Fast opening and closing of the valve, operation without impact;
(5) The spherical closing parts can be automatically positioned at the boundary position;
⑥ Working medium on both sides of the seal is reliable;
⑦ When fully open and fully closed, the sealing surface of the ball and seat is isolated from the medium, so the medium through the valve at high speed will not cause the erosion of the sealing surface;
⑧ compact structure, light weight, it can be considered as a reasonable valve structure for low temperature medium system;
⑨ Symmetrical valve body, especially welded valve body structure, can bear the stress from pipeline well;
⑩ Closing parts can withstand the high pressure difference when closing. (11) Ball valve welding body, can be directly buried in the ground, so that the inner parts of the valve is not eroded, high service life of up to 30 years, is the ideal valve for oil and natural gas pipelines.
Disadvantages:
(1) Because the main valve seat sealing ring material is ptfe, it is inert to almost all chemicals, and has the comprehensive characteristics of small friction coefficient, stable performance, not easy to aging, wide range of temperature and excellent sealing performance. But the physical characteristics of PTFE, including high coefficient of expansion, sensitivity to cold flow and poor thermal conductivity, require that the seat seal be designed around these characteristics. As a result, when the sealing material hardens, the reliability of the seal is damaged. Moreover, the temperature resistance of PTFE is low and can only be used under the condition of less than 180℃. Above this temperature, the sealing material will age. In the case of long-term use, it is generally only not used at 120℃.
② Its regulating performance is worse than the globe valve, especially the pneumatic valve (or electric valve).

Nortech is one of the leading industrial valve manufacturers in China with quality certification ISO9001.

Major products: Butterfly Valve, Ball Valve,Gate Valve, Check Valve, Globe Vavlve,Y-Strainers, Electric Acurator , Pneumatic Acurators .

 For more interest, welcom to contact  at: Email: sales@nortech-v.com