Alexandra Trevino Valves April 14th, 2019 - 12:16:08
Its typical use is to close or open the flow. When the valves are opened, the force inside the pipes descends to a minimum level. These valve types commonly functions as valves for preliminary use in any pipe operation. On the other hand, valves can't be utilized to regulate the movement of liquid in a direct style. It can either function to fully close or fully open the movement in the pipes.
A gate valve is one of the commonly used valves to open and close the flow of liquid from straight line medium. This can be found in a number of places. An instance would be in irrigation as well as used in different chemical plants to regulate the path of various types of fluids.
The third one is similar to ball check valves, but the plug that seals the valve is shaped like a cone. It also can be called a lift check valve in which the disc, sometimes called a lift, can be lifted up off its seat by higher pressure of inlet or upstream fluid to allow flow to the outlet or downstream side. The cone is held on a bar, allowing it to lift out of the way when the water is flowing and drop back into place when the water is off. If water backflows through the pipe, it pushes up against the cone, creating a seal that keeps it from going any further.
Generally speaking, the valve for low-pressure and non-corrosive fluid is made of cast iron or cast copper. The high or middle-pressure is made of cast steel or forged steel. As for the valve used in the high-temperature or high-pressure, it will select the alloyed steel as the main material. Beside, stainless steel, plastics, chlorimet such as titanium alloy or lead alloy are applicable for the main materials of the valve used for the corrosive fluid.
The last one is the valve type and sizing. Over-sizing of valves sometimes occurs when trying to optimize process performance through a reduction of process variability. Over-sizing the valve may hurt process variability in two ways. First, the oversized valve puts too much gain in the valve, leaving less flexibility in adjusting the controller. Best performance results when most loop gain comes from the controller. The second way oversized valves hurt process variability is that an oversized valve is likely to operate more frequently at lower valve openings where seal friction can be greater, particularly in rotary valves.
Two thousands years ago, the Chinese people 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 process and hydraulic machinery, the plug valve made of brass and lead appeared in Europe. Besides, with the wide application of boiler, in 1681 the safe valve with lever and heavy bob came into the world. Before the invention of the Watt steam engine, the plug valve and check valve were the most important valves. The steam engine leaded the valve into a new field namely mechanical industry.