- "Ονομαστική πίεση" κοινώς χρησιμοποιείται σύστημα - PN vs κλάση
Για το βαλβίδα "ονομαστική πίεση" κοινώς χρησιμοποιείται σήμανση σύστημα, το ευρωπαϊκό πρότυπο σύστημα (PN) αντιπροσωπεύεται από Γερμανία at δωμάτιο θερμοκρασία (120 βαθμός ) του του επιτρεπτό εργασίας πίεση ως η βάση για το "ονομαστική πίεση" σύστημα, κυρίως χρησιμοποιείται σε ISO, DIN, EN, BS πρότυπα. Class American Standard system (Class) is αντιπροσωπεύεται από the United States to a certain temperature under the permissible working pressure as a representative of the "temperature-pressure" system, mostly used in AMSE and other standards.
American Standard valves in the Class series (i.e., pounds), are a combination of temperature and pressure for a particular metal, according to ASME B16.34 calculation results. Due to the poundage and the nominal pressure of the temperature benchmark being different, the poundage and the nominal pressure are not a one-to-one correspondence, so in engineering, conversion can not simply be pressure conversion. For example, Class300 simply with the pressure conversion should be 2.1MPa, but if you take into account the use of temperature, the corresponding pressure will rise, according to the material temperature and pressure test to determine the equivalent of 5.0MPa. At the same time, in the U.S. "Temperature - Pressure" system, the other levels of 454 degree C as a benchmark, while the Class150 is 260 degree C as a benchmark. Class150 is based on 260 degree . Class150 of 25 carbon steel valves at 260 degree , the permissible stress of 1MPa, while the permissible stress at room temperature is much larger than 1MPa, about 2.0MPa. Therefore, you can not just follow the pressure change formula to change the nominal pressure temperature and pressure levels.
Αυτό που πρέπει να περισσότερο ενδιαφερόμενος είναι αυτό υπάρχουν δύο διαφορετικές τιμές in Class600 and Class1500 αντιστοιχούν στο ευρωπαϊκό Standard and American Standard. Take Class600 as an example, in the European standard system, the 10MPa stipulated in ISO 7005-1:2011 corresponds to Class600; in the American standard system, the 11MPa stipulated in ASME B16. 5 αντιστοιχεί σε Class600, so we can't say that Class600 corresponds to 11MPa or 10MPa, and the stipulations of different systems are different. different systems are different.
- Η κοινή μονάδα του αερίου πίεση και μετατροπή σχέση
Για την πίεση του το αέριο, Κίνα γενικά περισσότερο κοινώς χρησιμοποιείται της μάζα μονάδα "kgkg" to περιγράφω (μάλλον από "jin"), the unit kg. Its αντιστοιχία πίεση μονάδα is "kg/cm2 ", a kgkg of pressure is a kilogram of force acting on a square centimeter, converted to 1kg/cm2=0.98 bar ≈ 0.1MPa. Ομοίως, in foreign countries, for the pressure of the gas, the commonly used unit of pressure is "psi", the units are "1pound/inch2", that is, "pounds/square inch", the full name of the English Pounds per square inch. but more commonly used is to direct call the unit of mass, that is, pounds (LB.). All units into metric units can be derived: 1psi=1pound/inch2 ≈ 0.068bar, 1bar ≈ 14.5psi ≈ 0.1MPa.
