The Instrumentation Valves is a pipe accessory. It is used to change the channel cross-section and the flow direction of the media to control the flow of the transmission medium of a device. The sealing performance of the Instrumentation Valves is the ability of the sealing parts of the Instrumentation Valves to prevent the media from leaking. It is the most important technical performance index of the Instrumentation Valves. There are three sealing parts of the Instrumentation Valves: the opening and closing parts and the valve seat between the two sealing surface contact; packing and stem and packing material with the Department; valve body and the lid of the connection. One of the former leak is called the internal leakage, which is usually said lax, it will affect the Instrumentation Valves cut off the ability of the media. For the cut-off valve class, the internal leakage is not allowed. After the two leaks called leakage, that is, the media leak from the valve to the valve outside. Leakage will cause material loss, pollution of the environment, serious will cause accidents. For flammable and explosive, toxic or radioactive media, leakage is not allowed, so the Instrumentation Valves must have a reliable sealing performance.
After years of development, the number of Chinese enterprises in the valve ranks first in the world, all kinds of large and small valve business more than 6,000. Valve as a fluid delivery components, in recent years, with the national economic growth, the valve industry is developing very rapidly. From January to November 2007, the total industrial output value of China's valves and cocks reached RMB 84,288,398 thousand, an increase of 31.47% over the same period of last year. The accumulated sales revenue of products reached 80,571,055 thousand yuan, up by 29.36% over the same period of last year. The cumulative total profit of 5,772,097 thousand yuan, an increase of 44.16% over the same period last year. From January to August 2008, the total industrial output value of China's valves and cocks reached RMB 73,321,603,000, an increase of 27.02% over the same period of the previous year. The accumulated sales revenue was RMB 70,451,147,000, representing an increase of 27.27% over the same period of last year. Total profit was RMB4,470,009,000, an increase of 15.37% over the same period of last year. "Eleventh Five-Year" and the future for several years, China's petrochemical, natural gas, metallurgical industry, electricity, urban construction and other industries have a lot of demand for valves, is expected in the "Eleventh Five-Year" period, China's total demand for the valve Reaching 34.5 billion yuan, therefore, the valve industry has a huge market development space.
The Instrumentation Valves is a pipe accessory. It is used to change the channel cross-section and the flow direction of the media to control the flow of the transmission medium of a device. Specifically, the Instrumentation Valves has the following purposes:
(1) Turn on or cut off the media in the pipe. Such as gate valve, globe valve, ball valve, plug valve, diaphragm valve, butterfly valve and so on.
(2) to regulate and control the flow and pressure of the medium in the pipeline. Such as throttle, regulating valve, pressure reducing valve, safety valve and so on.
(3) change the direction of the flow of media in the pipeline. Such as distribution valve, three-way cock, three-way or four-way ball valve.
(4) to prevent the medium in the pipeline back. Such as a variety of different structures of the check valve, the end of the valve.
(5) separating the media. Such as steam traps with different structures, air traps and so on.
(6) to indicate and adjust the liquid level. Such as liquid level indicator, liquid level regulator and so on.
(7) other special purpose. Such as temperature control valve, over-current protection emergency shut-off valve.