Understanding valve principles

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Ball Valve: The valve seat of the ball plug valve is spherical. In order to allow fluid to pass through, a cylindrical passage is opened in the center of the ball. The ball in the ball plug valve can open and close 90 degrees. This ball is usually sandwiched in upstream and downstream Teflon bushings to withstand fluid pressure and perform opening or closing rotation. Therefore, when using a metal ball core, the corrosion resistance of the material and the roundness and precision of the ball should be taken into consideration. Its materials are generally bronze and stainless steel. Gate Valve: A valve that slides in or out of the body with a wedge-shaped seat to close or open the fluid is called a gate valve. The flow of fluid is always in a straight line. When fully open, the fluid resistance is small, and when half open, it is susceptible to vibration or corrosion, causing damage to the valve seat. Therefore, it is described as a representative of valves that are fully open or fully closed. And it has the highest usage rate in valves. Globe Valve: It is named because the shape of the bottom is similar to a ball. This type of valve has a layer of partitions at the bottom of the ball that is opposite to the bushing attached here, so that the valve seat can be opened up and down to adjust the flow rate. Although the fluid inlet and outlet are on the same line, the flow direction of the fluid in the base can change in an "S" shape. Check Valve: The so-called check valve refers to the ability to fix a single flow direction of fluid and prevent the reverse flow of another flow direction. The valve seat of the main body opens upward through the power of the fluid. ； But when the fluid flows back, the valve seat automatically closes according to the return pressure. Divided into (1), horizontal check valve. (2) Straight check valve. (3) Straight check valve. (4) Ball check valve. Butterfly Valve: Its basic structure is a tubular body, a disc-shaped valve seat and a valve stem, and the valve stem can open and close the valve seat at 90 degrees. This type of valve can leak or not leak depending on the material of the bushing when closed. If you want to completely seal it without leaking, you need to use a rubber elastomer bushing. ； If a small amount of leakage is allowed, metal bushings can be used. Because it can also be used to adjust the flow of high and low temperature gas and special fluids, it is also called a throttle valve.