I’m confused between the PN series and the CLASS series; please help me, friends
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What is the PN series, and what is the CLASS series? What are the criteria used? What value in MPa corresponds to each pressure level there? I just can’t figure it out
PN is the European standard, while class is the American standard
PN is the European standard, while CLASS is the American standard. The pressure value corresponding to the European standard is expressed in MPa, whereas that corresponding to the American standard is in LB. For example, the 150LB standard specified in HG20613—2009 corresponds to a pressure of 150 pounds, which is equivalent to PN20 under the European standard as defined in HG20592—2009, or 2.0 MPa. However, this pressure level is not specified in this standard
Refer to GB/T 1048 Pipe Fittings – Nominal Pressure and ASME B16.34
1. The biggest difference between European and American standards is the pressure rating. HG20592 specifies 9 pressure grades: PN2.5/6/10/16/25/40/63/100/160, with the unit being bar; HG20615 specifies 6 grades: Class150, Class300, Class600, Class900, Class1500, Class2500, which correspond to nominal pressures of PN20, PN50, PN110, PN150, PN260, PN420. The second difference is that the flange types according to European standards differ from those per American standards – European standards include plate-type butt-welded flanges, and there are more pressure grades available for European flanges. When designing equipment and choosing steel pipe flanges, European flanges are often preferred due to their lower weight and a wider range of pressure grades ； Flanges for pipe ends are often American standard flanges
The PN series meets national and European standards; it is also known as the German standard, and it is widely used. The pressure unit used is MPA. The CLASS series is intended for use with American-standard valves, and the pressure unit here is LB. Common pressure ratings include 150LB, 300LB, 400LB, 600LB, 900LB. 150LB corresponds to 2.0 MPa, 300LB corresponds to 5.0 MPa, 400LB corresponds to 6.8 MPa, 600LB corresponds to 11.0 MPa, 900LB corresponds to 15.0 MPa, and 1500LB corresponds to 26.0 MPa
Both PN and CLASS are dimensionless values that represent the temperature-pressure range that the flange can withstand. When using it, check the material and the corresponding temperature and pressure range. You can take a look at sections on temperature-pressure in HG20592 and HG20615. . . The maximum pressure values that the flange material inside can withstand within different temperature ranges
One is the European standard, and the other is the American standard
Excuse me, do PN20 and PN2.0 refer to the same thing? PN20 is common, but PN2.0 is seen occasionally as well, which is quite confusing. .
PN20 is 2.0 MPa, while PN2.0 is 0.2 MPa; the two are not the same