This document presents a recommended practice for fabrication and installation of copper tubing used in the distribution of medical gas and vacuum lines in health care facilities.? It provides guidance for implementation of the requirements of NFPA 99C@ Gas and Vacuum Systems.? Brazing procedures and brazers should be qualified in accordance with the latest edition of AWS B2.2@ Standard for Brazing Procedure and Performance Qualification or the ASME Boiler and Pressure Vessel Code@ Section IX@ Welding and Brazing Qualifications modified as required by NFPA 99C.This standard makes use of both U.S. Customary Units and the International System of Units (SI).? The measurements are not exact equivalents; therefore@ each system must be used independently of the other without combining values in any way.? The standard with the designation D10.13:2001 uses U.S. Customary Units.? The standard with the designation D10.13M:2001 uses SI Units.? The latter are shown in appropriate column in table and figures@ and within brackets?[ ] when used in the text.?