Butterfly valve or at home, we called the throttle valve acts like a ball valve and plug valve structure of the butter fly valve is a disk flat, rotating back and forth in a 90-degree angle, if the disk is placed parallel to the direction the flow. It will open the valve fully. And if placed perpendicular to the flow direction, it will close the valve. It works the same with the damper to close - open air in air conditioning systems in buildings and the use of disk instead of a ball or plug to block the flow, the butterfly valve is smaller than the ball valve and plug. valve (that is narrower than when measured in the direction of flow) and a lighter as well. The structure of the disk can not be said that the high pressure and temperature. Therefore, we often see a large butterfly valve in the pipe with water without any harm, such as cooling water. Air cooling system.
Figure 7 Butterfly valve (left), the valve stem rotates in small, close - open the valve, and (right) valve, a large gear in a closed system - open
From the rotating disk in a transverse direction of flow. The fluid pressure causes the disk to rotate to the desired position. Therefore, we often see the butterfly valve shaft to the gear for fixing the valve to close - how much open. This structure is not found in the ball valve or plug valve and the valve gear system will help to close the opening.
