Pneumatic valve pressure, how conversion between national standard American standard?

we usually used in PN, Class, all is a kind of representation method of stress, the difference is that they represent pressure corresponding to the reference temperature is different, the PN European system refers to the corresponding pressure under ℃, while the Class refers to the American standard. ℃ under the corresponding pressure. So in engineering swap can't simply stress conversion, such as CLass# conversion should be a simple with pressure. MPa, but if you consider to use temperature, its corresponding pressure is increased, according to the temperature of the material is equivalent to withstand voltage test is carried out. MPa。
a pneumatic valve system: one kind is Germany, Including our country) As a representative to room temperature ( Our country is, Germany is degrees) The allowable working pressure for the benchmark system of 'nominal pressure'. One is represented by the United States at a certain temperature under the allowable working pressure of the temperature and pressure system represented by America's system of temperature and pressure, in addition to the LB to degrees as a benchmark, other are in degrees at all levels as a benchmark. Lb ( psi=MPa） The number of carbon steel pneumatic valve in degrees, allowable stress for MPa, and the allowable stress at room temperature is much bigger than MPa, is about. MPa。 So, the general said LB the nominal pressure rating for the corresponding American standard. MPa, the nominal pressure rating for the LB corresponding. MPa, etc.
so, can't literally, in accordance with the pressure transform formula to transform the nominal pressure and pressure rating. PN is a numerically stress-related code, is to provide the reference in a convenient rounded number, PN is approximate in the number of compression MPa at room temperature, domestic pneumatic valve is usually used by the nominal pressure. Control of the carbon steel pneumatic valve pneumatic valve, refers to the maximum allowable working pressure when it is applied in ℃ below; For cast iron pneumatic valve body, refers to the maximum allowable working pressure when it is applied in ℃ below; For stainless steel pneumatic valve pneumatic control valve, refers to the maximum allowable working pressure when it is applied in ℃ below. When work at higher temperatures, pneumatic valve pressure is reduced.
American standard expressed as a class to nominal pressure pneumatic valve, the combination of the class is for a certain kind of metal calculation result of temperature and pressure, he according to ANSI B. Calculated on the basis of the standard. Class with the nominal pressure is not the main reason for one to one correspondence class is different from the temperature of the nominal pressure benchmark. We usually use the software to calculate, but also want to know the use form class to check. Japan's main said classes with K values. For the pressure of the gas, in China, we usually more commonly used its quality unit 'kg' description ( Rather than the 'jin') Kg, units. Its corresponding pressure unit is kg/cm, one kilogram of stress is a kilo of force on a square centimeter. Similarly, corresponding to foreign countries, for the pressure of the gas, commonly used pressure unit is 'psi', the unit is 'pound/inch', is 'Pounds per square inch,' called the English Pounds per square inch. But the more commonly used is directly call the quality unit, namely the pounds ( 磅。 , actually this LB. Is the previously mentioned pounds of force. Change all the units to metric units can be calculated: psi = pounds per inch of material. bar， bar≈. psi≈. MPa, Europe and the United States and other countries use psi as a unit. In the Class and the Class corresponding to the European standard and with two different values, MPa ( Corresponding class) Is the European system of regulation, it is in the ISO - - The inside of the Steel Flanges '; MPa（ Corresponding class) Is American system regulation, this is the ASME B. The rules of the inside. So you can't absolutely class that corresponds to the MPa, or MPa, different system of rules is different.