Valve related professional name

The main performance parameters of the valve for the nominal diameter, nominal pressure, working pressure and working temperature. First, the nominal diameter Nominal diameter DN is the pipeline system, all the pipe fittings with figures expressed in size, in order to distinguish between the threaded or outer diameter of those parts. Nominal diameter is used as a reference of the rounded figures, and the processing size is not exactly the same value. The nominal diameter is followed by a numeric sign followed by the letter "DN". Such as the nominal diameter of 250mm should be marked as DN250. Second, the nominal pressure Nominal pressure PN is a number with the pressure-related designation code is for reference with a convenient round integer. All pipeline attachments of the same nominal diameter indicated by PN value of the same nominal pressure have the same connection size that is suitable for the end connection type.When the nominal pressure is involved in our country, the unit of measurement is usually given for the sake of clarity, "MPA" .In Britain, the United States and other countries, although the concept has been included in the relevant standard nominal pressure, but in actual use is still used in English units Class .Because of the nominal pressure and pressure level temperature benchmark, So there is no strict correspondence between the two.The general correspondence between the two see table.Japanese standards there is a "K" level system, such as 10K, 20K, 40K, etc .. This pressure level concept and the British unit of pressure The same level, but the unit of measurement using metric Third, the pressure - temperature rating Valve pressure - temperature rating is the maximum allowable working pressure expressed in gauge pressure at the specified temperature. When the temperature increases, the maximum allowable working pressure The pressure - temperature rating data is the correct choice of flange, valve and fittings at different operating temperatures and working pressures Basis, is also a basic parameter in engineering design and manufacturing. Pressure-temperature ratings for various materials, see Chapter 4 for data, and many countries have established pressure-temperature ratings for valves, fittings and flanges. American Standard The pressure-temperature ratings for steel valves are as specified in ASME / ANSI B16.5a-1992 and ASME B16.34-1996 for the American Standard; the pressure-temperature ratings for cast iron valves are per ANSI B16.1- 1989 ~ B16.4-1989, ANSI B16.42-1985: The pressure-temperature ratings of bronze valves are as per ASME / ANSI B16.15a-1992, ASME B16.24-1991 1) US ASME / ANSI B16.5a-1992 provides the British units and metric units of two Flange size series, respectively, are applicable to the two units of the flange pressure and temperature ratings. In the standard Appendix D is given to determine the imperial Unit pressure - temperature rating method 2) The United States ANSI B16.42-1985 "ductile iron pipe flange and flange fittings" standard provides CL150 and CL300 ductile iron flange pressure - temperature rating in the standard appendix Prescribed pressure - temperature level The basic principles, scope of application, limitations and formulation procedures are basically the same with those of ASME / ANSI B16.5a-1992. 3) The American ASME B16.34-1966 incorporates the ASME / ANSI B16.5a-1992 flange connection Valve Temperature-Pressure Ratings Data The pressure-temperature ratings of flanged valves in this standard are based on the method of ASME / ANSI B16.5a-1992. This standard lists standards for flanged and butt-welded connections Pressure-Temperature Ratings Data Sheet for Class Valves and Butt Weld Couplings. There are more than 100 valve materials listed in the standard, divided into 27 groups. 2, the German standard German standard DIN2401-1977 second volume "pipe pressure level, steel and cast iron pipe parts allowable working pressure" is a more comprehensive pressure - temperature rating standards. Among them, lists the seamless pipe, welded pipe, flanges, valves, fittings and bolts in different materials, different temperature conditions allowable working pressure. The standard includes 6 flange materials, flange connection cast iron valve material 4, 5 cast steel, forged steel 5, these are the original material. Steel is carbon steel and low alloy steel, stainless steel is not included. The standard clearly states that when other materials different from the original material are selected, the allowable working pressure is calculated based on the ratio between the strength property value of the used material and the strength value of the raw material specified in the standard at 20 ° C. For stainless steel pressure-temperature ratings, ISO / DIS70651 "Steel Flanges" are supplemented. 3, the former Soviet Union standard The former Soviet Union standard TOCT356-1980 "nominal pressure of valves and piping accessories, test pressure and working pressure series," all in accordance with the standards of the Commission. In the former Soviet Union standard, the materials were grouped. In the standard will be below 200 ℃ maximum allowable working pressure values ​​are considered as working pressure at room temperature, and is equal to the nominal pressure. 4, the international standard international standard ISO / DIS7005-1-1992 "ordinary pipe flange" is the United States standard ASME / ANSI B 16.5a-1992 and the German standard nominal pressure level flange standard merged together. Therefore, the pressure - temperature rating standards were also used in the United States and Germany, two countries flange pressure - temperature rating standards for the development of methods and the corresponding data. Nominal pressure rating in ISO / DIS7005-1-1992 PN0.25,0.6,1.0,1.6,2.5,4.0 MPA is a German flange system; PN2.5,10,15,25,42 MPA belongs to the United States flange system. The pressure-temperature rating of each system applies only to the flange standard of the respective system. 5, the national standard of our country GB / T9124-2000 (appendix A) "steel pipe flange technical conditions" with reference to the German DIN2401-1977 and the United States ASME / ANSI B 16.5a-1992 standard pressure temperature rating principle And methods, using the flange materials commonly used in our country, with reference to international standards ISO / DIS7005-1-1992 were developed for the two nominal pressure series (PN0.25-4.0MPA, PN2.0-42.0MPA) flange pressure - Temperature rating. Standard specifies the 13 kinds of flange materials at 12 nominal pressure levels, the working temperature is 20-530 ℃ maximum allowable working pressure.