Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Pressure Loss Characterization of Plumbing Fittings


In the past, when water and energy use was less of an issue, plumbing systems were often over-designed with little need for accurately characterizing the relationship between pressure and flow in fittings and other plumbing components. As a result, there is no standardized method of test to quantify pressure-flow curves in fittings, and the data that are available are not sufficiently accurate to support the more demanding design processes that will be required in the future. To establish standardized and precise means of establishing pressure-flow relationships of plumbing fittings, the NIST Plumbing Hydraulics Laboratory was built. This laboratory contains state-of-the-art instrumentation to accurately measure water flow and pressure drop for a range of fittings using approaches identified in collaboration with NIST’s Fluid Metrology Group in the Physical Measurement Laboratory. Using this laboratory, data is being acquired for a range of fittings and components, and a draft method of test will be submitted to an appropriate standards development organization for further development and approval as an industry consensus standard.

Team Lead:  Natascha Milesi Ferretti

Created July 23, 2021, Updated February 15, 2024