IPS, or Iron Pipe Size, is a standard system used to define pipe dimensions. Contrary to a direct physical measurement of the pipe's outside diameter (OD), the sizing in the IPS standard is defined differently.
Defining IPS Dimensions
According to the reference, IPS pipe dimensions are defined by two main characteristics:
- A nominal OD (Outside Diameter): This is a standard size designation, not the actual, measured OD of the pipe. The true outside diameter of the pipe may differ slightly from the nominal size.
- A "schedule": This number relates directly to the pipe's wall thickness. Different schedules correspond to different wall thicknesses for a given nominal pipe size.
Together, the nominal OD and the schedule determine the specific dimensions of the IPS pipe, including its internal diameter (ID), which affects flow.
This method contrasts with systems like Copper Tube Size (CTS), which the reference notes is OD-controlled. In CTS, changes in wall thickness directly alter the internal diameter because the outside diameter is controlled. In IPS, the sizing system relies on the nominal OD and schedule to standardize dimensions.
