903.2 Use of Copper Tubing. ~ 903.2.1 Copper tube for underground drainage and vent piping shall have a weight of not less than that of copper drainage tube type DWV. 903.2.2 Copper tube for above ground drainage and vent piping shall have a weight of not less than that of copper drainage tube·type DWV. 903.2.3 Copper tube shall not be used for chem- ical or industrial wastes as defined in Section 811.0. 903.2.4 Hard-drawn copper tubing, in addition to the required incised marking, shall be marked in accordance with either ASTM B306, Copper Drainage Tube (DWV), or ASTM B88 Seamless Copper Water Tube as listed in Table 14-1. The colors shall be: Type K, green; Type L, blue; Type M, red; Type DWV, yellow. 903.3 Changes in direction of vent piping shall be made by the appropriate use of approved fittings, and no such pipe shall be strained or bent. Burred ends shall be reamed to the full bore of the pipe. 904.0 Size of Vents. 904.1 The size of vent piping shall be determined from its length and the total number of fixture units connected thereto, as set forth in Table 7-5. The diameter of an individual vent shall be not less than one and one-fourth (1-1/4) inches (32 mm) nor less than one-half (1/2) the diameter of the drain to which it is connected. In addition, the drainage piping of each building and each connection to a public sewer or a private sewage disposal system shall be vented by means of one (1) or more vent pipes, the aggregate cross-sectional area of which shall be not less than that of the largest required building sewer, as determined from Table 7-5. Vent pipes from fixtures located upstream from pumps, ejectors, backwater valves, or other devices that in any way obstruct the free flow of air and other gases between the building sewer and the outside atmo- sphere shall not be used for meeting the cross- sectional area venting requirements of this section. Exception: When connected to a common building sewer, the drainage piping of two (2) or more buildings located on the same lot and under one (1) ownership shall be permitted to be vented by means of piping sized in accordance with Table 7-5, provided the aggregate cross-sectional area of vents is not less than that of the largest required common building sewer. 77
904.2- 908.1 904.2 No more than one-third (1 /3) of the total permitted length, per Table 7-5, of any minimum- sized vent shall be installed in a horizontal position. Exception: When a minimum-sized vent is increased one (1) pipe size for its entire length, the maximum length limitation does not apply. 905.0 Vent Pipe Grades and Connections. 905.1 Vent and branch vent pipes shall be free from drops or sags, and each such vent shall be level or shall be so graded and connected as to drip back by gravity to the drainage pipe it serves. 905.2 Where vents connect to a horizontal drainage pipe, each vent pipe shall have its invert taken off above the drainage centerline of such pipe down- stream of the trap being served.
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- Fall '15