What is the nominal size (DN) of a valve?

DN：

A dimensional designation consisting of a combination of letters and numbers used for components in piping systems. It consists of the letters “DN” followed by a dimensionless integer. This number is directly related to characteristic dimensions such as the bore diameter or outer diameter (expressed in mm) of the end fitting.

Note:

1. Unless otherwise specified in the relevant standards, the number following the letters “DN” does not represent a measured value and should not be used for calculation purposes.
2. Unless otherwise specified in the relevant standards, the number following the letters “DN” does not represent a measured value and should not be used for calculation purposes.