A valve is a device that controls the flow speed, pressure or the management. The controlled fluid may work as liquid gas, the combination of gas and liquid or the mix of solid and liquid. The Moog Valve usually consists of body, seat, bonnet, parts for closing or opening, actuating apparatus, sealing element and so forth. The controlling use of the valve is dependent upon the actuating apparatus or the movement of the fluid that compels the sliding, turning or rotating of those parts for shutting or opening to modify the region of the flow passage.
Two thousands years ago, the Chinese people implemented the bamboo backward and plug in to water pipeline. Then later they implemented the sluice to the irrigational canal, then the plate test valve to bellows for smelting and so forth. Together with the development of smelting process and hydraulic machinery, the plug valve made of brass and direct appeared in Europe. Besides, together with the broad application of boiler, in 1681 the valve with lever and hefty bob came to the world. Before the creation of the Watt steam engine, the plug valve and check valve would be the main valves. The steam engine leaded the valve into a new area namely mechanical business.
Together with the increase of the steam flow rate and pressure, the plug can’t satisfy the amount of steam entry and exhaustion in any respect. In order to fix the problem, people then devised the slip valve. In 1840, the test valve with threaded stem and the wedge gate valve with threaded stem turned into the wonderful breakthrough at the valve area. The 2 valves did not just meet with the requirement for pressure and temperature in the time but also originally meet the demand for flow law. Afterwards, on account of the accelerated development of energy industry, oil industry, chemical industry and shipbuilding business, all sorts of high or center valves popped up like mushrooms. What is more, following the Second World War, possessing to the creation of new materials such as polymeric material, stainless steel, lubricating material, the older plug valve and butterfly valve benefit the new application and also the ball valve and diaphragm valve grow fast.