The eccentric hemispherical valve has the following advantages:
1. The fluid resistance is small, and its resistance coefficient is equal to the pipe length of the same length.
2. Simple structure, small size and light weight.
3.It is tight and reliable. At present, the sealing surface material of the ball valve is widely used in plastics and has good sealing performance. It has also been widely used in the vacuum system.
4. Convenient operation, fast opening and closing, only need to rotate 90 ° from fully open to fully closed, which is convenient for remote control.
5.The maintenance is convenient, the structure of the ball valve is simple, the sealing ring is generally movable, and it is convenient to disassemble and replace.
6. When fully open or fully closed, the sealing surfaces of the ball and valve seat are isolated from the medium, and the medium will not cause erosion of the valve sealing surface when the medium passes.
7.It has a wide range of applications, with a diameter ranging from a few millimeters to a few meters, and can be applied from high vacuum to high pressure.
8. Suitable for high flow rate.The straight-through flow channel and the sturdy eccentric valve plate make it suitable for high flow rates and vibration-free.
High platform ball valves can be divided into straight-through type, three-way type and right-angle type according to their channel position.The latter two ball valves are used to distribute the medium and change the flow direction of the medium.The installation and maintenance of three-piece ball valve should pay attention to the following matters:
1. Leave a position for the valve handle to rotate.
2. Cannot be used for throttling.
3 The ball valve with transmission mechanism should be installed upright.
The working principle of eccentric hemispherical valve
It relies on the rotating valve chain to make the valve unblocked or blocked.The ball valve switch is light, small in size, can be made into a large diameter, reliable in sealing, simple in structure, easy to maintain, the sealing surface and the spherical surface are often in a closed state, and it is not easy to be eroded by the medium. It is widely used in various industries.
The eccentric hemispherical valve is mainly used for cutting off in the pipeline
, Distribute and change the flow direction of the medium.The ball valve is a new type of valve that has been widely used in recent years. It has the following advantages:
1. The fluid resistance is small, and its resistance coefficient is equal to the pipe length of the same length.
2. Simple structure, small size and light weight.
3.It is tight and reliable. At present, the sealing surface material of the ball valve is widely used in plastics and has good sealing performance. It has also been widely used in the vacuum system.
4. Convenient operation, fast opening and closing, only need to rotate 90 ° from fully open to fully closed, which is convenient for remote control.
5.The maintenance is convenient, the structure of the ball valve is simple, the sealing ring is generally movable, and it is convenient to disassemble and replace.
6. When fully open or fully closed, the sealing surfaces of the ball and valve seat are isolated from the medium, and the medium will not cause erosion of the valve sealing surface when the medium passes.
7.It has a wide range of applications, with a diameter ranging from a few millimeters to a few meters, and can be applied from high vacuum to high pressure.When the ball rotates 90 degrees, it should show a spherical surface at the entrance and exit, so as to cut off the flow.
Eccentric hemispherical valve is a relatively new type of ball valve. It has some advantages unique to its own structure, such as frictionless switch, non-wearing seal, and small opening and closing torque.This can reduce the size of the actuator.Equipped with a multi-turn electric actuator, it can realize the adjustment and close shut-off of the medium.It is widely used in [wiki] petroleum[/wiki], [wiki] chemical industry[/wiki], urban water supply and drainage and other working conditions that require strict cut-off.
The working principle of the eccentric hemispherical valve is as follows:
A. Opening process
1 In the closed position, the ball is pressed against the valve seat by the [wiki]mechanical[/wiki] of the valve stem.
2 When the handwheel is turned counterclockwise, the valve stem moves in the opposite direction, and the angular plane at the bottom causes the ball to separate from the valve seat.
3 The valve stem continues to lift and interacts with the guide pin in the spiral groove of the valve stem, so that the ball begins to rotate without friction.
4 Until it reaches the fully open position, the valve stem is raised to the limit position, and the ball rotates to the fully open position.
B. Closing process
1 When it is closed, turn the handwheel clockwise, the valve stem begins to descend and the ball leaves the valve seat and starts to rotate.
2 Continue to rotate the handwheel, the valve stem is acted on by the guide pin embedded in the upper spiral groove, so that the valve stem and the ball rotate 90° at the same time.
3 When it is about to close, the ball has rotated 90° without contact with the valve seat.
4 In the last few turns of the handwheel, the angular plane at the bottom of the valve stem mechanically wedges and presses the sphere to make it tightly press on the valve seat to achieve a complete seal.
Structural features of eccentric hemispherical valve:
1. There is no friction when opening and closing.This function completely solves the problem of traditional [wiki]valve[/wiki] that affects the sealing due to mutual friction between the sealing surfaces.
2. Top-mounted structure.The valves installed on the pipeline can be directly inspected and repaired online, which can effectively reduce device shutdown and reduce costs.
3. Single valve seat design.Eliminates the problem that the medium in the valve cavity affects the safety of use due to abnormal pressure increase.
4. Low torque design.The valve stem with special structure design can be opened and closed easily with only a small handle.
5. Wedge-shaped sealing structure.The valve is sealed by the mechanical force provided by the valve stem, which presses the ball wedge onto the valve seat, so that the sealing performance of the valve is not affected by the change of the pipeline pressure difference, and the sealing performance is reliably guaranteed under various working conditions.
6. Self-cleaning structure of the sealing surface.When the sphere tilts away from the valve seat, the fluid in the pipeline passes through the sealing surface of the sphere uniformly at 360°, which not only eliminates the local washing of the valve seat by the high-speed fluid, but also washes away the accumulation on the sealing surface to achieve the purpose of self-cleaning .
Product Usage
The eccentric hemispherical valve is suitable for sewage treatment, pulp, alumina, and urban heating and heating applications where strict standards are required; it is suitable for control of power plants, hydraulic slag removal or gas transportation pipelines.
The structure of the eccentric hemispherical valve:
The eccentric hemispherical valve is divided into two types in terms of appearance structure:
1. Top-mounting type: mainly for the media with very serious erosion and wear. The upper-mounting structure is very convenient to replace and repair the damaged opening and closing parts. There is no need to remove the entire valve from the pipeline, which greatly saves maintenance time and cost.
2. Side-mounted type: The side-mounted type has a compact structure and a light valve, which is suitable for occasions that require valve installation space.
