A valve is a device which controls the flow price, stress or the direction. The controlled fluid can be the liquid, gas, the mixture of gas and liquid or the mixture of solid and liquid. The valve typically is composed of physique, seat, bonnet, parts for opening or closing, actuating device, sealing element and so on. The controlling function of the valve depends on the actuating device or the movement of the fluid which drives the sliding, rotating or turning of the parts for opening or closing to change the location of the flow passage.
Two thousands years ago, the Chinese people today applied the bamboo trunk and wooden plug into water pipeline. Then later they applied the sluice into the irrigational canal, the plate check valve into bellows for smelting and so on. With the development of smelting approach and hydraulic machinery, the plug valve produced of brass and lead appeared in Europe. Apart from, with the wide application of boiler, in 1681 the safe valve with lever and heavy bob came into the planet. Prior to the invention of the Watt steam engine, the plug valve and check valve have been the most significant valves. The steam engine leaded the valve into a new field namely mechanical sector.
With the boost of the steam flow price and pressure, the plug valve can not satisfy the number of steam admission and exhaustion at all. In order to solve the issue, people today then invented the slide valve. In 1840, the verify valve with threaded stem and the wedge gate valve with threaded stem come to be the terrific breakthrough in the valve field. The two valves did not only meet the requirement for pressure and temperature at that time but also initially satisfy the want for flow regulation. Later, mainly because of the fast improvement of power industry, oil industry, chemical sector and shipbuilding industry, all sorts of higher or middle valves sprang up like mushrooms. What’s a lot more, after the Second Globe War, owning to the invention of new supplies such as polymeric material, stainless steel, lubricating material, the old plug valve and butterfly valve achieve the new application and the ball valve and diaphragm valve create immediately.
All in all, step by step the valve manufacturing becomes one of the important sectors in the mechanical sector. There are a lot of applications for the valve. It is closely connected with our everyday life. For yoursite.com , the tap employed for operating water pipe and the minimizing valve made use of for liquefied petroleum gas stove are the valves. What’s additional, it is the important part for unique mechanical equipments such as gas engine, steam engine, compressor, pump, car, ship or aerocraft.