Fluids Flow Design and Engineering Metric Pipe Sizes Dn "Diametre Nominel" per ISO vs NPS "Nominal Pipe Size" Equivalent for DN 6 to DN 2200, NPS Schedule 5 to 30 Welded and Seamless PIpe

NPS is often incorrectly called National Pipe Size, due to confusion with the American standard for pipe threads, "national pipe straight", which also abbreviates as "NPS". The European and international designation equivalent to NPS is DN (diamètre nominal /nominal diameter/Nennweite), in which sizes are measured in millimetres, see ISO 6708. [2]

In plumbing pipe size is referred to as nominal pipe size - NPS, or "Nominal Pipe Size". The metric equivalent is called DN or "diametre nominel". The metric designations conform to International Standards Organization (ISO) usage and apply to all plumbing, natural gas, heating oil, and miscellaneous piping used in buildings.

2022年5月23日 · NPS（Nominal Pipe Size）：公称直径（通径）的一种表示方法。 是北美管道尺寸标准体系，以英寸为单位。 1英寸约等于25.4mm。 在ASME、API体系的标准文献中，单位为英寸。 如NPS2"。 需要指出的是DN公称通径是供参考用的一个方便的圆整数，与加工尺寸仅呈不严格的对应关系。 DN (Diameter Nominal)：公称直径（通径）的另一种表示方法。 用于管道系统的字母和数字组合标识，由字母DN和后跟的无量纲的整数数字组成。 需要指出的是DN公称通径 …

2023年1月16日 · DN number is used to indicate the size of a pipe and it’s based on the internal diameter. PN number is used to indicate the maximum pressure rating of a pipe and it’s based on the material and wall thickness of the pipe. Together, DN and PN numbers are commonly used to identify and specify the size and pressure rating of pipes.

The DN value does not provide actual physical pipe dimensions but is used as a reference number that indicates the size of a pipe or fitting. The pipe sizes are designated by DN followed by a number to indicate standard pipe size. For example, DN50 indicates a 2″ NPS pipe; Similarly, DN80 indicates a 3″ NPS pipe.

NPS is American Standard of pipe size notation while NB is European and DN is standard from metric unit system. NPS gives information about related outer diameter of pipe, NB provides information related to internal diameter of pipe and In case of DN its niether Outer or Internal diameter but close to internal diameter of pipe.

2025年3月10日 · DN is the nominal true diameter in industrial fittings and piping systems and is an important size basis for pipe fittings. DN is often used in American standards to indicate the …

It is common to identify pipes by inches using NPS or " Nominal Pipe Size ". The metric equivalent is called DN or "diametre nominel". The metric designations conform to International Standards Organization ISO usage and apply to all plumbing, natural gas, heating oil, and miscellaneous piping used in buildings.

DN stands for diametre nominal, which denotes the size of a pipe (specifically, its inside diameter) in millimeters (mm). NPS, or nominal pipe size, is merely the non-metric equivalent in which the diameter is measured in inches (in.). In print, pipe size designations are not followed by an abbreviation of the unit of measurement.