What are the advantages and how to classify the ash unloading ball valve?

Ash ball valve is evolved from the globe valve. It has the same rotary 90-degree lifting action, except that the cock body is spherical and has a circular through hole or passage through its axis. The ratio of the spherical surface and the channel opening should be such that when the ball rotates 90 degrees, the spherical surface should be present at the inlet and outlet, thus intercepting the flow.

 

1. role

 

The working principle of the ash unloading ball valve is to make the valve unblocked or blocked by the rotary valve. The pneumatic ball valve switch is light, small in size, can be made into a large diameter, reliable in sealing, simple in structure, convenient in maintenance, the sealing surface and the spherical surface are often in a closed state, and are not easily eroded by the medium. It is widely used in various industries.

 

Pneumatic ash discharge ball valve and plug valve is the same type of valve, only its closing piece is a sphere, the sphere around the center line of the valve body for rotation to achieve open, closed a valve.

 

Pneumatic discharge valve in the pipeline is mainly used to cut off the speed, distribution and change the direction of the flow of the medium. Pneumatic ball valve is a new type of valve which is widely used in recent years.

 

2. advantages

 

1. The fluid resistance is small, and its resistance coefficient is equal to the pipe section of the same length.

 

2. Simple structure, small size and light weight.

 

3. Close and reliable, the current ball valve sealing surface material widely used plastic, good sealing, in the vacuum system has also been widely used.

 

4. Easy to operate, open and close quickly, from full open to full close as long as the rotation of 90 °, easy to remote control.

 

5. Easy maintenance, pneumatic ball valve structure is simple, the seal ring is generally active, disassembly and replacement are more convenient.

 

6. When fully open or fully closed, the sealing surface of the ball and the valve seat is isolated from the medium. When the medium passes, it will not cause erosion of the valve sealing surface.

 

7. Wide range of application, diameter from small to a few millimeters, large to a few meters, from high vacuum to high pressure can be applied. Pneumatic ash ball valve has been widely used in petroleum, chemical industry, power generation, papermaking, atomic energy, aviation, rockets and other departments, as well as people's daily life.

 

3. classification

 

(I) floating pneumatic ball valve

 

The ball of the pneumatic ash discharge ball valve is floating. Under the action of the medium pressure, the ball can produce a certain displacement and press on the sealing surface of the outlet end to ensure the sealing of the outlet end.

 

Pneumatic ash discharge ball valve ball valve structure is simple, good sealing, but the ball to bear the load of the working medium all passed to the outlet seal ring, so it is necessary to consider whether the sealing ring material can withstand the working load of the ball medium. This structure is widely used in medium and low pressure ball valves.

 

(II) fixed pneumatic ball valve

 

The ball of the pneumatic ball valve is fixed and does not move after being pressed. Fixed ball valve with a floating valve seat, by the medium pressure, the valve seat to produce movement, so that the sealing ring pressed on the ball to ensure sealing. Usually in the upper and lower shaft with the ball is equipped with bearings, the operating torque is small, suitable for high pressure and large diameter valves.

 

In order to reduce the operating torque of the pneumatic ball valve and increase the reliability of the seal, oil-sealed ball valves have appeared in recent years. The special lubricating oil is injected between the sealing surfaces to form a layer of oil film, which enhances the sealing performance and reduces The operating torque is more suitable for high-pressure and large-diameter ball valves.

 

(III) elastic ball pneumatic ball valve

 

The ball of the pneumatic ash discharge ball valve is elastic. Ball and valve seat seals are made of metal materials, the sealing pressure is very large, relying on the pressure of the medium itself has reached the requirements of the seal, external force must be applied. This valve is suitable for high temperature and high pressure medium.

 

The elastic sphere is to open an elastic groove at the lower end of the inner wall of the sphere to obtain elasticity. When the channel is closed, the wedge head of the valve stem is used to make the ball open and the valve seat to seal. Before rotating the ball, loosen the wedge head, and the ball will return to its original shape, so that there is a small gap between the ball and the valve seat, which can reduce the friction of the sealing surface and the operating torque.

 

Pneumatic ash discharge ball valve according to its channel position can be divided into straight-through, three-way and right-angle. The latter two ball valves are used to distribute the medium and change the flow direction of the medium.