Edwina Dorsey Valves April 14th, 2019 - 12:34:32
As a rule customarily, the sealing face for the low-pressure valve mostly applies the brass or brozen. The sealing faces of the high or middle-pressure valves are made of stainless steel. If the valve has high requirement for the temperature or pressure, cobalt base alloy is used as the main material of the sealing face. What's more, the polymeric material is widely used in the valve field. For example, PTEF material is applied into the seat of ball valves, different rubber materials for seal packing ring of the butterfly valve and septum of the diaphragm valve. All in all, the sealability of these materials is better than that of metal in the available temperature range.
Within a manual operated rubber valve, there are three basic design components; the body, disc and cover. With a specialized rubber casing, the valve offers, to all intents and purposes, a service to users that is maintenance free without distortion of the valve disc and seat. If compared to conventional check valves, a manual rubber valve will be found to operate for longer periods with minimal downtime.
Valves have been playing a major role in the transportation of fluids in various industries like oil and petrochemicals, pharmaceutical industries and food and beverage industries and have become vital parts of many types of machinery too.
If the sealability is not good or the strength is not intensive, the parts may be destroyed. Thus, it will result in the economic loss in different degree, such as transporting the poisonous, explosive or corrosive fluid. And even it will lead to the serious accident. In order to ensure the sealing and strength of the valve, the manufacture should not only obey the related standards to design and produce the product but also should properly select the material.
The determining factor of this valve in every aspect of usage, no matter whether the processing involves liquids, fluids or heavy duty and abrasive materials, is the elastomer sleeve. It is the controlling factor of any Air Pinch Valve, not only in respect of usual high performances, but for total versatility in operating in adverse conditions and environments. However, although valve sizing is of a critical priority, the selection of the correct elastomer sleeve for an operation is a maximum priority.
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.