February 26, 2026
From the 2024 UPC Illustrated Training Manual, Chapter 6, WATER SUPPLY AND DISTRIBUTION
610.12.2 Tubing Systems Using Copper Fittings. Maximum velocities through copper fittings in tubing other than copper shall not exceed 8 ft/s (2.4 m/s) in cold water and 5 ft/s (1.5 m/s) in hot water.
Previous sections discussed velocities and the affect that high velocities have on the piping system. These sections reiterate the importance of staying within the velocity ratings of the materials used. Under normal conditions using Tables 610.3, 610.4 and 610.10 will keep velocities within those limits. Water distribution systems using copper alloy fittings can be either copper pipe systems or plastic pipe or tubing systems utilizing copper alloy fittings. The same velocities apply to the copper alloy fitting as it does to the copper pipe. There have been reports of copper alloy fittings failing due to high velocities in plastic tubing systems. When installing and sizing these systems be sure to follow the manufacturer’s installation instructions and/or Appendix A.
From the 2024 UMC Illustrated Training Manual, Chapter 5, EXHAUST SYSTEMS
507.4.4 Factory Built. Factory-built grease duct enclosures shall be protected with a through-penetration firestop system classified in accordance with ASTM E814 or UL 1479 having an “F” and a “T” rating equal to the fire resistance rating of the assembly being penetrated from the point at which the duct penetrates a ceiling, wall, or floor to the outlet terminal. [NFPA 96:4.3.4]
Listed factory-built and field-applied grease duct enclosures still need to maintain the integrity of the fire resistiveness of the building. Where penetrations of the building assemblies are allowed, the “F” (flame transmission) and “T” (temperature transmission) ratings of these listed grease duct enclosures shall not reduce the time-resistance rating of the wall or floor/ceiling assembly required by the building code of the jurisdiction. The prescriptive method of penetration shown in the listed installation instructions should be followed exactly. These instructions should be left on the job site for inspection purposes.
(This is not to be considered the official position of IAPMO, nor is it an official interpretation of the Codes.
IAPMO
IAPMO develops and publishes the Uniform Plumbing Code®,the most widely recognized code of practice used by the plumbing industry worldwide; Uniform Mechanical Code®; Uniform Swimming Pool, Spa and Hot Tub Code®; and Uniform Solar Energy, Hydronics and Geothermal Code™ — the only plumbing, mechanical, solar energy and swimming pool codes designated by ANSI as American National Standards — and the Water Efficiency Standard (WE-Stand)™. IAPMO works with government, contractors, labor force, and manufacturers to produce product standards, technical manuals, personnel certification/educational programs and additional resources in order to meet the ever-evolving demands of the industry in protecting public health and safety.
Last modified: February 26, 2026