Pneumatic pneumatic ball valves are mainly used in pipelines to cut off quickly, distribute and change the flow direction of media. Pneumatic pneumatic ball valve is a new type of valve widely used in recent years. It has the following advantages:
1. The fluid resistance is small, and its resistance coefficient is equal to that of pipe sections with the same length.
2. Simple structure, small volume and light weight.
3. The classification and characteristics of pneumatic ball valves are tight and reliable. At present, plastic is widely used as the sealing surface material of pneumatic ball valves with good sealing performance, and it has also been widely used in vacuum systems.
4. It is easy to operate and can be opened and closed quickly. It only needs to rotate 90 ° from full opening to full closing to facilitate remote control.
5. It is easy to maintain, the pneumatic pneumatic ball valve is simple in structure, the sealing ring is generally movable, and it is easy to remove and replace.
6. When the valve is fully opened or closed, the sealing surfaces of the ball and valve seat are isolated from the medium. When the medium passes through, it will not cause erosion of the valve sealing surface.
7. It has a wide range of applications, ranging from a few millimeters to several meters in diameter, from high vacuum to high pressure.
8. Because the power source of pneumatic pneumatic ball valve is gas, it is generally 0.2-0.8MPa, which is relatively safe. If the pneumatic pneumatic ball valve leaks, compared with the hydraulic and electric valves, the gas can be discharged directly, which does not pollute the environment and has high safety.
9. Compared with manual and turbine rotating pneumatic ball valves, pneumatic pneumatic ball valves can be configured with large caliber. (Manual and turbine rotating pneumatic ball valves are generally below DN300 caliber, and pneumatic pneumatic ball valves can currently reach DN1200 caliber.) Pneumatic pneumatic ball valves have been widely used in petroleum, chemical, power generation, paper making, atomic energy, aviation, rocket and other departments, And people's daily life.

6. Check whether there is outflow or inflow of manifold not included in the assessment
Check flow chart item 6. When the process technician finds that the measured flow is significantly different from the reference value, the analysis of various reasons often focuses on the flow instrument and ignores the reasons for the outflow/inflow of the measuring pipeline manifold. When discussing with the field service instrument engineer, the process operator often confidently said that there was no manifold outflow or inflow. However, field service experience shows that after comprehensive inspection and elimination of various other fault possibilities, the measured flow is often inconsistent with the so-called "actual measurement" due to the outflow or inflow of manifold, which is not an individual case. Therefore, the presence or absence of manifolds should also be investigated as an aspect. For example, investigate whether there is a manifold in the pipeline between the measuring point as a reference (such as ultrasonic flowmeter, container and pool) and the electromagnetic flowmeter, and whether the valve is tightly closed. In addition, check whether the container or pool is connected with other inflow and outflow sources.