Interpretation #7199

Published June 23, 2013

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Original Request

Code Version
2010
Code
BUILDING
Code Description
Building
Chapter
4
Section
403.3.2
Topic
Fire Sprinkler system pump

Question

Is it the intent of Section 403.3.2 to require separate mains for a one pump fire sprinkler system?

Answer Published 06/23/2013 at 8:30 PM

NO. 403.3.2 States that "Required fire pumps
shall be supplied by connections to a
minimum of two water mains." That statement, however, is
subordinate to 403.3 where it states, "Buildings and
structures shall be equipped throughout with an automatic
sprinkler system in accordance with Section 903.3.1.1 and a
secondary water supply where required by
Section 903.3.5.2." This is all new ICC verbiage for 2009.
In turn, IBC 903.3.5.2 has been revised (in Florida) to
read, "Reserved." In FBC Building 2010 903.3.5.2 there
is clearly no Florida intent to require dual water supplies.
Since the mandate for dual water supplies in 403.3 is
contingent on such a requirement existing in 903.3.5.2,
403.3 does not mandate dual supplies either. Since 403.3.2
is subordinate to 403.3, no such
requirement exists or is intended in 403.3.2.

Commentary

The answer to the comment is also NO. 403.3.1 talks about two risers (most likely AKA standpipes) but says nothing about two pumps. 903.3.5.2 requires the secondary water supply for seismic concerns. [F] 903.3.5.2 Secondary water supply. A secondary on-site water supply equal to the hydraulically calculated sprinkler demand, including the hose stream requirement,shall be provided for high-rise buildings assigned to Seismic Design Category C, D, E or F as determined by this code. The secondary water supply shall have a duration of not less than 30 minutes as determined by the occupancy hazard classification in accordance with NFPA 13. Exception: Existing buildings.