The difference between fixed ball valve and floating ball valve

1. Floating ball valve
The ball of the floating ball valve is floating. Under the action of medium pressure, the ball can produce a certain displacement and press tightly on the sealing surface of the outlet end to ensure the seal of the outlet end. The floating ball valve is small in size, light in weight, simple in structure and good in sealing performance, but the load of the working medium on the ball is completely transmitted to the outlet sealing ring, so it is necessary to consider whether the material of the sealing ring can withstand the working load of the ball medium. This structure is widely used in medium and low pressure ball valves.
Features and performance of floating ball valve
Small size, light weight, simple structure, the ball has a free floating function, which can better ensure the sealing; the ball valve uses a ball with a circular through hole as the opening and closing part, and the ball circles the center of the valve stem under the drive of the valve stem. Rotate ~90 degrees to complete the opening and closing function; it has the characteristics of compact structure and quick switch. Turning 90 degrees can close the valve and cut off the pipeline medium; the diameter of the ball channel is the same as that of the pipeline, with small flow resistance and large flow capacity; The stem is bottom-mounted, which prevents the accident of the stem passing through and ensures the safety of use;
2. Fixed ball valve
The ball of the fixed ball valve is fixed and does not move after being pressurized. Fixed ball and ball valves are equipped with floating valve seats. After being subjected to medium pressure, the valve seat moves, so that the sealing ring is pressed tightly on the ball to ensure the sealing. Usually, bearings are installed on the upper and lower shafts with the ball, and the operating torque is small, which is suitable for high pressure and large diameter valves.
Features and performance of trunnion ball valve
Fixed ball valves are suitable for various medium and high pressure pipelines, used to cut off or connect the medium in the pipeline, choose different materials, and can be respectively applied to water, steam, oil, liquefied gas, natural gas, coal gas, nitric acid, acetic acid , oxidizing medium, urea and other media, widely used in petrochemical, electric power and water conservancy industries. Common actuation methods for trunnion ball valves are worm gear drive, manual, electric and pneumatic. Most trunnion ball valves are flanged, but there are also welded trunnion ball valves.
Simply put: the general difference between fixed ball valve and floating ball valve is:
a. Floating ball valve – the ball of the valve core rotates freely between the two seat seals by means of the valve stem.
b. Fixed ball valve – the ball of the valve core is connected with the valve stem and rotates with the center of the valve stem, a ball valve with a floating ball and an elastic movable sleeve valve seat.

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