DS 2-8 Earthquake Protection for Water-Based Fire ... - FM Global

2-8 Earthquake Protection
Page 44 FM Global Property Loss Prevention Data Sheets
• Schedule of sway bracing type, size, and design criteria (length, angle from vertical, and load
capacities), and
• Details of attachment to the structure and to the piping, including verification of structural capacity
to withstand seismic load, details of sizing and load capacities of fasteners, and verification of load
capabilities of anchors not covered in this data sheet.
B. Location of flexible couplings and seismic separation assemblies.
C. Location of clearances around piping for seismic purposes.
D. Anchorage or seismic design details for storage racks that have in-rack sprinklers.
E. Anchorage or seismic design details for suspended ceilings beneath which sprinklers are installed.
F. For fire pump installations, all seismic design details as outlined in Section 2.2.5.
G. For water storage tanks or reservoirs, all seismic design details as outlined in Section 2.2.6.
2.3 Using Other Codes and Standards
Other codes and standards listed below, when used with the noted limitations, exceptions, and additions,
provide earthquake protection of fire protection systems similar to that recommended in this data sheet.
2.3.1 National Fire Protection Association (NFPA) Standards
2.3.1.1 NFPA 13, 2007 Edition
NFPA 13, Standard for the Installation of Sprinkler Systems, 2007 Edition, Section 9.3, “Protection of Piping
Against Damage Where Subject to Earthquakes” (and its associated appendix), is similar in most respects
to this data sheet’s recommendations for the sprinkler system itself. However, NFPA 13 does not address
some items (such as earthquake protection of water supplies and pumps, or anchorage of equipment) that
can impact sprinkler systems.
NFPA 13 (2007), Section 9.3, can be used with the changes noted below to provide earthquake protection
similar to that recommended in this data sheet.
2.3.1.1.1 Bracing of Piping: In addition to the NFPA 13 (2007) requirements, adhere to the recommendations
from Section 2.2 of this data sheet for the following items related to bracing of piping.
A. In multistory buildings, lay out intermediate 4-way bracing on risers so that bracing is provided at each
floor having a supply main.
B. Brace horizontal manifolds at the base of risers per Section 2.2.1.1.2(C) of this data sheet.
C. Provide 4-way bracing at both the top and bottom of vertical feedmains and crossmains 6 ft (1.8 m)
or longer per Section 2.2.1.1.3(A) of this data sheet.
D. Do not omit lateral bracing on feedmains and crossmains (regardless of size) nor on branch lines 4
in. (100 mm) and larger where the pipe is supported by short rod hangers (i.e., do not apply NFPA 13
Section 9.3.5.3.8 to these pipes).
E. Do not use wraparound U-hangers and U-hangers that hold the pipe tight against the underside of a
structural member as lateral braces on feedmains and crossmains, regardless of size (i.e., do not apply
NFPA 13 Section 9.3.5.3.9 to feedmains and crossmains). U-bolts, however, may be used as lateral
braces per Section 2.2.1.3.2 of this data sheet.
F. Provide lateral and longitudinal braces at changes of direction for horizontal feedmains and crossmains
per Section 2.2.1.1.4(A) of this data sheet.
G. Provide longitudinal bracing on branch lines 2- 1 ⁄ 2 in. (65 mm) and larger per Section 2.2.1.1.5(B) of
this data sheet. Branch line longitudinal bracing should not be used to brace the crossmain.
H. Limit the l/r ratio for braces used in compression to 200 or less (modification of NFPA 13 Section
9.3.5.8.2). Limit the l/r ratio for braces used in tension to 300 or less. Do not use cable or wire bracing
(i.e., do not apply NFPA 13 Section 9.3.5.2.2).
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