Is the statement "An 8 inch tube will have an outside diameter equal to an 8 inch pipe" true or false?

The statement is false because an 8-inch tube does not have the same outside diameter as an 8-inch pipe. Instead, the term "8-inch" for pipes generally refers to the nominal pipe size (NPS), which is a standardized ID (inner diameter). The actual outer diameter (OD) of a pipe is typically larger than the nominal size due to the thickness of the pipe wall, which varies based on the pipe schedule or type.

For example, an 8-inch schedule 40 steel pipe has an OD of 8.625 inches, while an 8-inch tube, designed under different standards (like those for structural applications), can have a different OD based on its specifications. This discrepancy in dimensions reflects the varied engineering standards and utility purposes for pipes and tubes. Consequently, knowing the specific standards and measurements applicable to the materials in use is crucial for accurate fittings and connections in pipefitting.