The nominal diameter is the size of all the pipe fittings in the piping system, and the nominal diameter is a convenient round integer for reference, which is not strictly related to the machining size. The nominal path is followed by a numeric symbol with the letter "DN".
The nominal path (nominal diameter), also known as the average outer diameter (mean outside diameter).
This is a thin tube with a metal tube, and the outer diameter of the tube is different from the inner diameter of the tube, so the average value of the outer diameter of the pipe and the inner diameter of the tube is called the pipe diameter.
DN is a nominal path, nominal diameter (or nominal diameter), which is the general caliber of various pipes and piping accessories. The same nominal diameter pipe and pipe accessories can be interconnected with each other, which is interchangeability. It is not the actual pipe diameter or inner diameter, though its value is close to or equal to the pipe inner diameter.
The nominal diameter (also known as nominal diameter and nominal diameter) is used in order to make the pipe and pipe fittings unify. For example, the thickness of welded pipe can be divided into thin wall steel tube, ordinary steel pipe and thickened steel tube. Its nominal diameter is not an outer diameter or an inner diameter, but a nominal size approximating the inner diameter of a common steel tube. The diameter of each nominal diameter corresponds to a diameter, and its inner diameter varies with the thickness. The nominal diameter can be expressed in the metric mm and can be expressed by the British in. With nominal diameter pipeline accessories, meaning with tube