The comparative advantages and disadvantages of the ball valve

Is evolved, it has the opening and closing member is a sphere, the sphere around the stem axis of rotation of 90 ° to achieve the purpose of opening and closing the stopcock. Ball valve for cutting the main pipe, distribution and change the direction of medium flow, designed to be V-shaped opening of the ball valve also has a good flow adjustment function.
Advantages:
① having the lowest flow resistance (actual);
(2) not stuck at work (in the absence of lubricant), it can be reliably used in corrosive medium and low boiling point liquid;
③ greater pressure and temperature ranges, can be completely sealed;
(4) can be fast opening and closing, opening and closing times of certain structures of only 0.05 to 0.1s order to secure for the test bed automation system. Rapid opening and closing valves, the operation no impact.
The ⑤ spherical Close parts can be automatically positioned on the boundary position;
The ⑥ working medium in a reliable seal on both sides;
⑦ in the fully open and fully closed, the ball and seat sealing surface and the dielectric isolation, high-speed media through the valve does not cause erosion of the sealing surface;pneumatic fitting
The ⑧ compact, light weight, that it is the most reasonable valve structure for low-temperature dielectric system;
⑨ valve body symmetry, especially welded body structure, can well withstand the stress from the pipe;
(10) Close pieces can withstand the pressure differential when closed.
⑾ fully welded ball valve body can be buried in the ground, so that the valve internals from erosion, the maximum service life of up to 30 years, oil, natural gas pipeline valve ideal.electric solenoid valve
Disadvantages:
(1) because the main valve seat ring material is PTFE, it is almost all chemical substances are inert, and has a low coefficient of friction, stable performance, easy to aging, a wide temperature range and excellent sealing performance The integrated features. But the physical properties of PTFE, including a higher coefficient of expansion of the cold flow sensitivity and poor thermal conductivity requirements of the valve seat sealing must be designed around these characteristics. Therefore, when the sealing material is hardened, the reliability of the seal is compromised. Moreover, polytetrafluoroethylene lower temperature levels is less than 180 ° C, only in the case of use. Exceeding this temperature, the sealing material is aging. Consider the long-term use, usually only at 120 ℃.
(2) its regulation performance relative to the cut-off valve to be worse, especially pneumatic valve (or electric valve).air cylinder manufacturers