What is the O.D (outside diameter) of an 8" nominal pipe size?

The outside diameter (O.D.) of an 8" nominal pipe size is 8 5/8 inches. The nominal size of a pipe refers to a standardized designation that approximates the pipe's diameter. However, the actual measurements can differ due to manufacturing standards and material specifications.

In the case of steel pipes, the O.D. is often slightly larger than the nominal size. For an 8" nominal pipe, the industry standard defines the O.D. to be 8 5/8 inches. This means that when selecting fittings or valves, it's crucial to know the actual O.D. to ensure compatibility with the piping system.

This knowledge is critical for pipefitters and plumbers, as using the precise dimensions will affect welding, joining, and overall system integrity. Understanding these specifications is essential in ensuring that installations adhere to building codes and operational efficiency.