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New piping for 4 new heads on an existing system, hydrostatic test or system pressure?

Question asked by mfarmer on Dec 11, 2019
Latest reply on Dec 12, 2019 by nocivus

Question on NFPA 13 25.2.1 Hydrostatic Tests section.  

Section states that "Modifications to existing piping systems shall require testing at system working pressure. 

Section states "Where modification is made to an existing system affecting more than 20 sprinklers, the new portion shall be isolated and tested at not less than 200 psi for 2 hours.  


If you are adding a minimum number of heads (lets say 4) to an existing piping system, would you have to hydro statically test the new pipe being installed for the new heads before tying into the existing system?  Or should this be tested at system pressure?  Would the new pipe installed not be considered a modification to an existing system?