610.6 Friction and Pressure Loss — 2025 California Plumbing Code

California Plumbing Code (Title 24, Part 5) · 2025 edition · updated 2026-10-19 · California

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Italicized text is a California amendment to the model code, as printed in the official publication.

Cite as: 2025 California Plumbing Code (Title 24, Part 5) § 610.6 · Effective January 1, 2026 · Official source: Building Standards Commission

Except where the type of pipe used and the water characteristics are such that no decrease in capacity due to the length of service (age of system) is expected, friction-loss data shall be obtained from the “Fairly Rough” or “Rough” charts in Appendix A of this code. Friction or pressure losses in a water meter, valve, and fittings shall be obtained from the same sources. Pressure losses through water-treating equipment, backflow prevention devices, or other flow-restricting devices shall be computed in accordance with Section 610.2.

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▸Contents — California Plumbing Code (Title 24, Part 5)

California Plumbing Code (Title 24, Part 5)

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