Up to and including DN 300 mm pipe, what does "nominal pipe size" refer to?

Nominal pipe size refers to a standardized system used in the plumbing and piping industries to classify pipe dimensions. For pipes up to and including DN 300 mm, the term "nominal pipe size" specifically refers to the nominal inside diameter. This sizing system allows for the categorization of pipes by their internal diameter, which is a critical factor in determining the flow capacity and compatibility with fittings and fixtures.

In practical applications, knowing the nominal inside diameter helps engineers and technicians ensure that piping systems function efficiently and effectively. While nominal pipe sizes encompass nominal outside diameter and wall thickness in larger or more specialized contexts, within the range specified, the internal diameter is directly linked to the pipe’s ability to carry fluids. This understanding is essential for anyone working with refrigeration and HVAC systems, as it affects performance and system design.