Valve Body

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Valve Body

Post  landoo on Thu May 30, 2013 8:08 pm

Normal practice requires user-specified control valve body materials, especially the special conditions or serious conditions with the valve. Many common conditions of the valve is the basic requirement to use common materials, such as carbon steel and stainless steel. In most cases, the required body material is the same material as the pipeline, mainly stainless steel, chrome-molybdenum steel (usually called chromium-molybdenum). Carbon may be used in the main valve common material. GDP, it is an ideal material for non-corrosive fluids. Carbon steel is also widely used neat and condensing operation. Its optimum performance at high temperatures to 800 ℉ (425 ℃) under continuous operation, even at up to 1000 ℉ (535 ℃) or higher temperature conditions. Its cost ratio increased slightly, but cheaper than other steel alloys.
Carbon may be used in the main valve common material. GDP, it is an ideal material for non-corrosive fluids. Carbon steel is also widely used neat and condensing operation. Its optimum performance at high temperatures to 800 ℉ (425 ℃) under continuous operation, even at up to 1000 ℉ (535 ℃) or higher temperature conditions. Its cost ratio increased slightly, but cheaper than other steel alloys.
Chrome-molybdenum steel is a good material, its performance is located between carbon and stainless steel. It is resistant than steel, high pressure and temperature, high pressure steam so that it can be processed and flushing operation of condensation. Its strength than carbon steel and stainless steel is almost the same, but not as good as chrome-molybdenum steel corrosion resistance of stainless steel. Special alloys are specified for special working conditions or serious condition of the valve. For example use Hastelloy B and C, or titanium, in order to avoid uncoordinated and fluid, such as the highly acidic fluids. Other cases, the choice of Mengna Er or bronze conditions for oxygen, for safety reasons where sparking material selection is dangerous.
Body is made of casting, forging or bar material made or manufactured by pipeline tees and flanges. Because manufacturers use a larger volume production processes and manufacturing cost is the lowest. Need for large angle valve body manufactured. As a general rule, the valve cap or the valve cap (used to seal the top portion of the body part) to use the same material as the valve body. While most used instead of casting rods manufactured. General The one exception is pressed against chromium molybdenum valve, which valve size in 6in (DN150) or more hours, the regular use of stainless steel bonnet.
Special conditions for the use of a valve forging security level for the nuclear one, the warranty a design life of 30 years. Thus requiring high performance stainless steel forgings body, should have a high purity, low defect, low segregation and fine grain, and excellent high temperature mechanical properties and good corrosion resistance, but also has a certain proportion of α phase. However, the existing mechanical properties of austenitic steel manufacturing process can not meet the technical requirements of the manufacturing process so it is very important.

landoo

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