1、 Precautions before construction
1. The burial depth shall be in accordance with the gas construction regulations. If the burial depth exceeds the construction regulations, protective pipes must be used.
2. After excavation, first remove the stones, crushed stones and other sundries, and then pave and press them with sand about 10cm thick.
3. The piping of pneumatic ball valve and connection joint shall be kept horizontal and vertical before construction.
4. The distance between burial and other buried objects shall be kept: ① For buried objects above 60 ℃ such as regional heating, the distance between THP and other protective measures shall be kept above 30cm. ② Water supply pipe, electrical facilities, communication cable: more than 30cm. ③ Sewer pipe: more than 20cm.

3、 Advantages of pneumatic ball valve
1. It has the lowest flow resistance (actually zero).
2. It can be reliably used in corrosive media and low boiling point liquids because it will not get stuck during operation (without lubricant).
3. Complete sealing can be achieved within a large pressure and temperature range.
4. It can realize fast opening and closing, and the opening and closing time of some structures is only 0.05~0.1s to ensure that it can be used in the automation system of the test bench. When quickly opening and closing the pneumatic ball valve, there is no impact during operation.
5. The spherical closure can be automatically positioned in position.
6. The working medium shall be reliably sealed on both sides.
7. When fully open and fully closed, the sealing surfaces of the ball and valve seat are isolated from the medium, so the medium passing through the pneumatic ball valve at high speed will not cause erosion of the sealing surface. 8. With compact structure and light weight, it can be considered as the most reasonable pneumatic ball valve structure for cryogenic medium system.
9. The valve body is symmetrical, especially the welded valve body structure, which can well withstand the stress from the pipeline.
10. The closing element can withstand the high differential pressure when closing.
11. The pneumatic ball valve with fully welded valve body can be directly buried underground, so that the internal parts of the pneumatic ball valve are not corroded, and the maximum service life can reach 30 years. It is the most ideal pneumatic ball valve for oil and natural gas pipelines. Introduction to high-pressure pneumatic ball valve: high-pressure pneumatic ball valve is defined in GB/T21465-2008 Terminology of Pneumatic Ball Valve as a pneumatic ball valve whose opening and closing parts (ball) are driven by the valve stem and rotate around the axis of the valve stem. High pressure pneumatic ball valve was introduced in the 1950s. With the rapid development of science and technology, the continuous improvement of production process and product structure, it has rapidly developed into a major valve category in a short period of 40 years. In western countries with developed industries, the use of high-pressure pneumatic ball valves is increasing year by year. In China, pneumatic ball valves are widely used in petroleum refining, long-distance pipeline, chemical industry, paper making, pharmacy, water conservancy, power, municipal administration, steel and other industries, and occupy a pivotal position in the national economy. The high-pressure pneumatic ball valve is mainly used to cut off or connect the medium in the pipeline, as well as to regulate and control the fluid. The hard sealed V-shaped pneumatic ball valve has a strong shear force between its V-shaped ball core and the metal valve seat of hardfacing carbide, which is especially suitable for media containing fiber, small solid particles, etc. The multi vent ball valve can not only flexibly control the confluence, diversion and flow direction switching of media on the pipeline, but also close any channel to connect the other two channels. This type of pneumatic ball valve shall be installed horizontally in the pipeline. Working principle of high-pressure pneumatic ball valve: high-pressure pneumatic ball valve can rotate 90 degrees. The plug body is a ball with a circular through hole or channel passing through its axis. The pneumatic ball valve is mainly used to cut off, distribute and change the flow direction of the medium in the pipeline. It can be closed tightly with only 90 degree rotation and a small rotating torque. Pneumatic ball valve is most suitable for use as switch and shut-off valve, but recent development has designed pneumatic ball valve to be used for throttling and flow control, such as V-type pneumatic ball valve. The main characteristics of high-pressure pneumatic ball valve are its compact structure, reliable sealing, simple structure, easy maintenance, sealing surface and spherical surface are always in closed state, not easy to be eroded by media, easy to operate and maintain, suitable for general working media such as water, solvent, acid and natural gas, and also suitable for media with poor working conditions, such as oxygen, hydrogen peroxide, methane and ethylene, It is widely used in various industries. The valve body of the pneumatic ball valve can be integral or combined.