How are pipe sizes classified?
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There are DN and CLASS; I can’t tell the difference, like what does 1” equal? DN=CLASS, and so on. . . . . . . . . . . . . . . . . .
Original poster, take a look at this to see if it’s helpful to you: Table of nominal pipe sizes and nominal diameters in the chemical industry http://bbs.hcbbs.com/viewthread.php?tid=386390
1 inch = DN25mm class is a pressure rating unit; it has nothing to do with inches. Enai Technical Support
1\" = 25.4 mm, where each 1/8 is what is commonly referred to as a fraction; for example, four fractions equal 1/2“
1 inch = 25.4 mm; where each 1/8 mm is what is commonly referred to as one fen, for example, two fen is 1/4"
1\"=25.4mm, which is equivalent to the nominal DN25； CLASS represents the pressure class, and its relationship with the nominal pressure is as follows: CLASS 150, 300, 400, 600, 800, 900, 1500, 2500, 3500, 4500; Nominal pressure in MPa: 2.0, 5.0, 6.4, 10.0, 13.0, 15.0, 25.0, 42.0, 56.0, 76.0. What does the author mean by DN=CLASS? Could it be a typo? :) This post was last edited by myzfs on 2009-3-10 13:36 ]
DN is the nominal diameter; in China it is expressed in mm, while in the United States it is expressed in inches. 1 inch = 25.4 mm. The PN nominal diameter: the correspondence between PN according to the petrochemical standard SH and the CLASS values in the American standard ASME B6.5 is as follows: PN/MPa CLASS/psi (pounds): 1.6 2.0 150; 2.5 4.0 5.0 300; 6.3 6.8 400; 11.0 (10) 600; 15.0 900; 26.0 (25.0) 1500; 42.0 2500
DN is the nominal diameter, in mm, while PN is the nominal pressure, in MPa. There are too many specific pipeline distinctions; you can buy books on this topic and read them carefully
What was said upstairs is great! For example, DN100 corresponds to 4 inches, and it has nothing to do with the weight class! Also, those who have the ASME B6.5 standard, please upload it! Thank you!
Seamless steel pipes are generally specified by the outer diameter multiplied by the wall thickness, with the inner diameter denoted by DN, whereas welded steel pipes are expressed in inches