1 Project overview background and research and development significance
1.1 The overview of the research and development project of metal seat pneumatic ball valve is based on the continuous improvement of the single unit capacity and parameter level of domestic thermal power generation units, which puts forward higher requirements for the performance of power generation equipment such as wear resistance, corrosion resistance, high temperature resistance, oxidation resistance, etc. The problems of wear and high temperature corrosion in power plant equipment have brought potential safety hazards and accidents to power plant equipment, increased maintenance costs and reduced utilization ratio of power generation equipment. As a new technology of material surface strengthening, protection and size recovery, thermal spraying technology can improve the utilization rate of power generation equipment, reduce the maintenance cost of equipment, and is of great significance to reduce the cost of power generation. It is widely used in equipment maintenance and machinery manufacturing. Under the high temperature and high pressure industrial conditions, the internal leakage of the valves in the high temperature and high pressure drainage system will cause huge energy waste and increase system wear. Traditional stop valves and gate valves can not meet the requirements of high-temperature and high-pressure working conditions. The development of high-temperature and high-pressure metal seat pneumatic ball valve (DN40~DN60) has technical advantages, which can solve the problems of high-quality medium leakage and equipment wear in the thermal system.
1.2 The research and development project of high temperature and high pressure metal seat pneumatic ball valve (DN4O~DN60) of research and development significance focuses on the extension of supersonic thermal spraying technology, because this technology has broad application prospects in terms of anti-corrosion of the last stage blades of power plant steam turbines, and greatly improving the wear resistance of key parts of steam turbines, boilers and other equipment. The application of high temperature and high pressure metal seat pneumatic ball valve can solve the problem of equipping high performance valves for boiler, steam turbine proper and pipeline drainage water existing in most power plants in China at present, which will effectively reduce the internal leakage of high-grade working medium, effectively optimize the thermal system, and improve the thermal efficiency of the unit. The promotion and application of high-temperature and high-pressure metal seat pneumatic ball valves (DN40~DN60) in the power industry can replace a large number of imported similar products, improve the technical level of high-temperature and high-pressure valves in China, and effectively reduce the equipment procurement costs of enterprises. Therefore, this research project has practical significance.

What factors affect the service life of pneumatic butterfly valve?
The factors affecting the service life are generally caused by improper use, mainly including the unreasonable use of the device, frequent and violent pressure impact, which is easy to cause the hose to burst.
During the installation, the length, steel wire layer, joint shape and size of the selected rubber hose should be reasonable, and the bending level of the rubber hose should be minimized. Large bending and twisting will greatly reduce the service life of the rubber hose, and some corresponding measures should be taken in the parts prone to friction.
As for the burst phenomenon of rubber hose, it is usually caused by the sudden increase of pressure.
For chemical plants with particularly high corrosion resistance, PTFE stainless steel hose is commonly used.