The ball valve consists of a hollow rotating ball placed in the middle of a shaft. Thanks to the rotation movement of the shaft, this ball rotates 90° within the valve body and provides fluid control.
Ball valves are reliable and robust. They can perform their duties safely even if they remain in the same position for a long time. It also allows frequent changes of spindle position. However, their intended use is generally fully open and fully closed. Fluid controls are not good except for fully open or fully closed positions. Therefore, their use as a regulating valve is not recommended.
Ball valves can be produced by many brands at temperatures up to 1000 bar and 400 °C, in various material structures such as metal, plastic and ceramic. However, when ball valves are used for adjustment, the fluid often gets stuck between the body and the ball. This water accumulated in cold weather expands in the ball and valve body, causing cracks or damage in the valve. This is a significant disadvantage. If a ball valve is to be used in environments where the air temperature drops below 0 °C, a cold-resistant (freeze proof type) valve must be used.
A vent is provided on the upstream side of the valve for cryogenic fluids or products that may expand inside the ball.
One of the most critical problems in the use of ball valves is pollution. Especially when the valves are used in drinking water or food factories, the water accumulated between the valve body and the ball causes bacteria formation or mixing during the use of different fluids. This situation harms firstly human health and then the quality of production. To prevent this accumulation, the gaps created by the ball with the body are closed by extending the surfaces on which the ball sits.
This type of valves are called "Cavity Filler Ball Valve" without a gap, and the seals and valve materials used in food or drinking water applications must be suitable for food and human health.
