Question: Can an (Existing) underground storage/pressure tank be used for both Sprinkler and domestic water supply for a newly rehabilitated building that is to comply with all new Codes and Standards?
NFPA 13R Section 9.3 indicates that the water supply source, if a pressure tank, shall be installed in accordance with NFPA 13, and NFPA 22. A project that I am working on has an existing 7400 gal. underground domestic hydro-pneumatic storage tank (with two underground well supplying make up). The building it is under a total rehabilitation Project (R2 Occupancy) and the tank is now to be used/designed for both domestic, and fire protection use. My concern is that 13R indicates to comply with NFPA 13, and NFPA 22. Section 18.104.22.168.4 of NFPA 13 clearly states that pressure tanks shall not be used to supply other than sprinklers and hand hose attached to sprinkler piping. NFPA 22, section 7.1.2 indicates pressure tanks shall not be used for any other purpose.
Please advise / clarify as the Design Engineer is indicating that because the system was Designed as an NFPA 13R system, that NFPA 13 is not applicable and they can use the tank for both domestic water and sprinkler supply. As the AHJ, I am not seeing that. I would think that you would have to comply with NFPA 13 as stated in 13R section 9.3 seeing that the tank as well as the building is considered a "Change of Use".
J. Adams - DASNY Code Administrator