Examples for
Pipes
Nominal pipe size (NPS) is a North American set of standard pipe sizes that defines the outer diameter with a nondimensional number. Besides the outer diameter, an additional pipe dimension called the pipe schedule can be used to specify the wall thickness of the pipe in question. Additional properties of a pipe can be constrained by specifying the material such as a steel pipe or a PVC pipe.
Pipe Sizes
Properties of a pipe can be computed based on a diameter specification that can also include length.