is a quarter turn shut-off valve that controls the flow of fluids by a rotary ball. The spherical rotary ball consists of a straight bore through it. The pipe is in the open position when the bore is aligned in the same direction as the flow, allowing the fluid to pass through it. When the bore is rotated 90 degree from the flow path, the valve is closed, and the flow is blocked. Ball valves are used in residential and commercial application for its reliable sealing properties and long service life. The image below is an example of a sectional view of a ball valve.
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Valve stem: The valve stem is a rotary shaft connecting the internal ball to the outside lever which when turned rotates the ball.
.O-ring: The o-ring is used to create a seal between the stem and housing of the valve. NBR (Nitrile rubber) is the most commonly used material for the O-ring.