ICC Subscriptions
 
1615.10.16 ASCE 7, Section 13.6.8. Replace ASCE 7, Section 13.6.8 by the following:

13.6.8 Piping systems.
Unless otherwise noted in this section, piping systems shall be designed for the seismic forces and seismic relative displacements of Section 13.3. ASME pressure piping systems shall satisfy the requirements of Section 13.6.8.1. Fire protection sprinkler piping shall satisfy the requirements of Section 13.6.8.2. Elevator system piping shall satisfy the requirements of Section 13.6.10.

Where other applicable material standards or recognized design bases are not used, piping design including consideration of service loads shall be based on the following allowable stresses:


a.
For piping constructed with ductile materials (e.g., steel, aluminum or copper), 90 percent of the minimum specified yield strength.

b.
For threaded connections in piping constructed with ductile materials, 70 percent of the minimum specified yield strength.

c.
For piping constructed with nonductile materials (e.g., cast iron or ceramics), 10 percent of the material minimum specified tensile strength.

d.
For threaded connections in piping constructed with nonductile materials, 8 percent of the material minimum specified tensile strength.

Piping not detailed to accommodate the seismic relative displacements at connections to other components shall be provided with connections having sufficient flexibility to avoid failure of the connection between the components.


13.6.8.1 ASME Pressure piping systems.
Pressure piping systems, including their supports, designed and constructed in accordance with ASME B 31 shall be deemed to meet the force, displacement and other requirements of this section. In lieu of specific force and displacement requirements provided in ASME B 31, the force and displacement requirements of Section 13.3 shall be used.

13.6.8.2 Fire protection sprinkler piping systems.
Fire protection sprinkler piping designed and constructed in accordance with NFPA 13 shall be deemed to meet the force and displacement requirements of this section. The exceptions of Section 13.6.8.3 shall not apply.

Exception:
Pipe hangers, bracing and anchor capacities shall be determined in accordance with material chapters of the California Building Code, in lieu of using those in NFPA 13. The force and displacement requirements of Section 13.3 or those in the NFPA 13 may be used for design.

13.6.8.3 Exceptions.
Design of piping systems and attachments for the seismic forces and relative displacements of Section 13.3 shall not be required where one of the following conditions apply:

1.
Trapeze assemblies are used to support piping whereby no single pipe exceeds the limits set forth in 3a. or b. below and the total weight of the piping supported by the trapeze assemblies is less than 10 lb/ft (146 N/m).

2.
The piping is supported by hangers and each hanger in the pipingrun is 12 in. (305 mm) or less in length from the top of the pipe to the supporting structure. Where pipes are supported on a trapeze, the trapeze shall be supported by hangers having a length of 12 in. (305 mm) or less. Where rod hangers are used, they shall be equipped with swivels, eye nuts or other devices to prevent bending in the rod.

3.
Piping having an Rp in Table 13.6-1 of 4.5 or greater is used and provisions are made to avoid impact with other structural or nonstructural components or to protect the piping in the event of such impact and where the following size requirements are satisfied:

a.
For Seismic Design Categories D, E or F and values of Ip greater than one, the nominal pipe size shall be 1 inch (25 mm) or less.

b.
For Seismic Design Categories D, E or F where Ip = 1.0 the nominal pipe size shall be 3 inches (80 mm) or less.

The exceptions above shall not apply to elevator piping.


13.6.8.4 Other piping systems.
Piping not designed and constructed in accordance with ASME B 31 or NFPA 13 shall comply with the requirements of Section 13.6.11.