What does the DN and PN represent on the flange?
Note 1: the number of the letter PN followed does not represent the measured value, not applied to the calculation purpose unless otherwise specified in the relevant standards. Note 2: the term PN is not meaningful except for the relevant piping component standards. Note 3: pipe element allows pressure depending on the PN number, material and design of components and allowed working temperature, etc., allow the pressure in the corresponding standard pressure temperature rating given in the table. Note 4: all piping elements with the same PN and DN values shall have the same size as the flanges corresponding to them.
Our company is specialized in producing flannel. I can tell you explicitly that DN is the specification, which is the specification. And PN is the pressure. These are not perfect. The most complete should have the execution standard, material and so on.
Nominal diameter, also called mean outside diameter. Nominal diameter is all pipeline fittings in the piping system with the size of the digital representation, nominal diameter is a convenient rounded number for reference, and machining dimension is not only strict relationship. The nominal size of the "DN" is followed by a digital marker. The DN is the nominal size, the nominal size (or the nominal diameter), which is the general diameter of various pipes and piping accessories. The same nominal diameter of the pipe and pipeline fittings can connect each other, interchangeable. It is not on the actual meaning of pipe diameter or inner diameter, although its value with pipe diameter is relatively close to or equal. PN, nominal pressure.
