About ball valve, include trunion ball valve ,floating ball valve

A ball valve, one type of quarter turn valve, is quite literally a ball placed in a passageway through which fluid flows. The ball has a hole through it, by which the valve opens and closes. When the ball is positioned so that the hole runs the same direction as the passageway, the fluid simply flows through the hole, and the valve is open. However, when the ball is positioned so that the hole is perpendicular to the passageway, the fluid cannot pass through, and the valve is closed. The ball is controlled from outside the valve, often with a handle that is turned 90 degrees, or a quarter turn, back and forth to open and close the valve.

The basic ball valve, described above, is a two-way valve. This ball valve has a
single, straight passageway bored through the ball, making two openings: one on each side, an inlet and an outlet. A ball valve can also be a three-way valve if a third hole is bored partially through the ball, until it meets the main hole, forming a T. A three-way ball valve can shut off one or all of the three passageways it connects.

Ball valves are durable and usually work to achieve perfect shutoff even after years of disuse. They are therefore an excellent choice for shutoff applications (and are often preferred to globe valves and gate valves for this purpose). They do not offer the fine control that may be necessary in throttling applications but are sometimes used for this purpose.

Ball valves are used extensively in industrial applications because they are very
versatile, supporting pressures up to 1000 bar and temperatures up to 482°F (250°C). Sizes typically range from 0.2 to 11.81 inches (0.5 cm to 30 cm). They are easy to repair and operate.The body of ball valves may be made of metal, plastic or metal with a ceramic center. The ball is often chrome plated to make it more durable.
A ball-check valve is a type of check valve with a ball without a hole for a disc.

Ball valve, basicaly have two type ball fixed way. Trunion ball valve and floating ball valve.The key difference beteween a floating ball valve and a trunnion mounted ball valve is how each achieves a line seal. Trunion mounted ball valves are uses a spring mechanism and/or line pressure assistance to drive the upstream seat against the stationary ball. The surface area exposed to the pressure through the relatively small passageway is actually just the back of the seat.

The floating ball valve utilize natural line pressure to press and seal the ball against the downstream seat. The line pressure is exposed to a greater surface area - the entire upstream face of the ball, which is an area equal to the actual pipe size.