313.3 Suspended Piping — 2025 California Mechanical Code

Suspended piping or tubing shall be supported at intervals not to exceed those shown in Table 313.3.

TABLE 313.3

HANGERS AND SUPPORTS

MATERIALS	TYPES OF JOINTS	HORIZONTAL			VERTICAL
Cast	Lead and Oakum	5 feet, except 10 feet where 10 foot lengths are installed1, 2, 3	5 feet, except 10 feet where 10 foot lengths are installed1, 2, 3	5 feet, except 10 feet where 10 foot lengths are installed1, 2, 3	Base and each floor, not to exceed 15 feet
Cast	Compression Gasket	Every other joint, unless over 4 feet then support each joint1, 2, 3	Every other joint, unless over 4 feet then support each joint1, 2, 3	Every other joint, unless over 4 feet then support each joint1, 2, 3	Base and each floor, not to exceed 15 feet
Cast-Iron Hubless	Shielded Coupling	Every other joint, unless over 4 feet then support each joint1, 2, 3, 4	Every other joint, unless over 4 feet then support each joint1, 2, 3, 4	Every other joint, unless over 4 feet then support each joint1, 2, 3, 4	Base and each floor, not to exceed 15 feet
Copper & Copper Alloys	Soldered, Brazed, Threaded, or Mechanical	11⁄2 inches and smaller, 6 feet; 2 inches and larger, 10 feet	11⁄2 inches and smaller, 6 feet; 2 inches and larger, 10 feet	11⁄2 inches and smaller, 6 feet; 2 inches and larger, 10 feet	Each floor, not to exceed 10 feet5
Steel Pipe for Water DWV	Threaded or Welded	3⁄4 inch and smaller, 10 feet; 1 inch and larger, 12 feet	3⁄4 inch and smaller, 10 feet; 1 inch and larger, 12 feet	3⁄4 inch and smaller, 10 feet; 1 inch and larger, 12 feet	Every other floor, not to exceed 25 feet5
Steel Pipe for Gas	Threaded or Welded	1⁄2 inch, 6 feet;3⁄4 inch and 1 inch, 8 feet; 11⁄4 inches and larger, 10 feet	1⁄2 inch, 6 feet;3⁄4 inch and 1 inch, 8 feet; 11⁄4 inches and larger, 10 feet	1⁄2 inch, 6 feet;3⁄4 inch and 1 inch, 8 feet; 11⁄4 inches and larger, 10 feet	1⁄2 inch, 6 feet;3⁄4 inch and 1 inch, 8 feet; 11⁄4 inches every floor level
Schedule 40 PVC and ABS	Solvent Cemented	All sizes, 4 feet; allow for expansion every 30 feet3	All sizes, 4 feet; allow for expansion every 30 feet3	All sizes, 4 feet; allow for expansion every 30 feet3	Base and each floor; provide mid-story guides; provide for expansion every 30 feet
CPVC	Solvent Cemented	1 inch and smaller, 3 feet; 11⁄4 inches and larger, 4 feet	1 inch and smaller, 3 feet; 11⁄4 inches and larger, 4 feet	1 inch and smaller, 3 feet; 11⁄4 inches and larger, 4 feet	Base and each floor; provide mid-story guides
CPVC-AL-CPVC	Solvent Cemented	1⁄2 inch, 5 feet; ¾ inch, 65 inches; 1 inch, 6 feet	1⁄2 inch, 5 feet; ¾ inch, 65 inches; 1 inch, 6 feet	1⁄2 inch, 5 feet; ¾ inch, 65 inches; 1 inch, 6 feet	Base and each floor; provide mid-story guides
Lead	Wiped or Burned	Continuous Support	Continuous Support	Continuous Support	Not to exceed 4 feet
Steel	Mechanical	In accordance with standards acceptable to the Authority Having Jurisdiction	In accordance with standards acceptable to the Authority Having Jurisdiction	In accordance with standards acceptable to the Authority Having Jurisdiction	In accordance with standards acceptable to the Authority Having Jurisdiction
PEX	Cold Expansion, Insert and Compression	1 inch and smaller, 32 inches; 11⁄4 inches and larger, 4 feet	1 inch and smaller, 32 inches; 11⁄4 inches and larger, 4 feet	1 inch and smaller, 32 inches; 11⁄4 inches and larger, 4 feet	Base and each floor; provide mid-story guides
PEX-AL-PEX	Metal insert and metal compression	1⁄2 inch 3⁄4 inch 1 inch	}	All sizes 98 inches	Base and each floor; provide mid-story guides
PE-AL-PE	Metal insert and metal compression	1⁄2 inch 3⁄4 inch 1 inch	}	All sizes 98 inches	Base and each floor; provide mid-story guides
PE-RT	Insert and Compression	1 inch and smaller, 32 inches; 11⁄4 inches and larger, 4 feet	1 inch and smaller, 32 inches; 11⁄4 inches and larger, 4 feet	1 inch and smaller, 32 inches; 11⁄4 inches and larger, 4 feet	Base and each floor; provide mid-story guides
Polypropylene (PP)	Fusion weld (socket, butt, saddle, electrofusion), threaded (metal threads only), or mechanical	1 inch and smaller, 32 inches; 11⁄4 inches and larger, 4 feet	1 inch and smaller, 32 inches; 11⁄4 inches and larger, 4 feet	1 inch and smaller, 32 inches; 11⁄4 inches and larger, 4 feet	Base and each floor; provide mid-story guides

For SI unit: 1 inch = 25.4 mm, 1 foot = 304.8 mm

Notes: 1 Support adjacent to joint, not to exceed 18 inches (457 mm). 2 Brace not to exceed 40 feet (12 192 mm) intervals to prevent horizontal movement. 3 Support at each horizontal branch connection. 4 Hangers shall not be placed on the coupling. 5 Vertical water lines shall be permitted to be supported in accordance with recognized engineering principles with regard to expansion and contraction, where first approved by the Authority Having Jurisdiction.

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