# Circumferential

Published: October 31, 2018 | Last updated: July 5, 2023

## What Does Circumferential Mean?

Circumferential, in general, is an adjective that refers to the circumference, or distance around, the surface of something. In trenchless technology, it refers to the distance around the inner surface of the pipe. It represents an actual circumference, unlike the pipe diameter, which may be nominal – that is to say, it may be called an X-in pipe, when in fact it is X -0.25 inches in diameter: a nominal 9-inch pipe may be 8.75 inches in diameter.

## Trenchlesspedia Explains Circumferential

A pipe circumference is always the accurate, inside circumference. If the circumferential measurement of a pipe is known, its exact interior diameter can be determined by dividing the circumference by Pi and dividing the result by two. The formula to determine the exact inside diameter (“ID”) of gas pipe looks like this: Where the circumferential measurement of the pipe =C: (C/Pi)/2.

To determine the exterior diameter of the pipe – its outside diameter (“OD”) add twice the wall thickness to the pipe's ID.

Synonyms

circumference