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Fire Flow Requirement

Question asked by ishrestha on Oct 18, 2018
Latest reply on Mar 8, 2019 by r_s_ryan

My question is regarding NFPA Fire Code “Building Other Than One and Two-Family Dwellings” and Code 18.5.4 “Minimum Number of Fire Hydrants for Fire Flow.

 Proposed scenario:

80,000 Square Foot Class II building is proposed for the future development. Per NFPA Table, minimum required fire flow is 6000 gpm for 4 hour.

Fire flow test was conducted near the project site. Per Fire flow test; two (2) hydrant was used, flowing hydrant had two 2.5” outlet open. The static pressure was 90 psi, residual pressure was 79 psi, and pitot reading was 38 psi. Based on this data, the available fire flow at 20 psi is 5625 gpm.

Does this mean that it does not meet the fire flow requirement per NFPA Table (6000 gpm)? What if we are planning to provide the fire loop around the building and fire hydrant at every 350 feet? Will this satisfy the NFPA requirement?

I am little confused, Per NFPA Code, aggregate fire flow capacity of all fire hydrant within 1000 ft of the building, measured in accordance with and shall be not less than the required fire flow determined in accordance with Section 18.4.

If I plan to propose a fire loop around the building with fire hydrant at every 350 feet and fire flow test near project verified that fire flow capacity of existing hydrant is 5625 gpm, will this not satisfy the fire flow requirement per NFPA. (almost 2X5625 gpm = 11250 gpm (NFPA code

Please advise! I look forward for your reply and suggestion.

To summarize my question:

  1. fire flow requirement per table is from one hydrant or combination of hydrant?
  2. Can I multiply the fire flow test results from project vicinity, if I plan to add fire loop with at minimum 2 hydrant at every thousand feet?