AnsweredAssumed Answered

In NFPA 13 subsection it limits restoring normal air pressure in the system to 30 minutes. What is the significance of this and if a system takes 1.75 hrs to restore normal air pressure is this system at risk?

Question asked by mbeck on Jun 13, 2016
Latest reply on Sep 12, 2018 by fireman

I just witnessed a full hydro test of a dry system and observed two details that I believe are out of compliance with the code NFPA 13. The first is the time it takes for water to reach the inspection test connection. says for systems protecting dwelling units the system shall be sized such that an initial water is discharged from system test connection in not more than 15 seconds. the system I was looking at this took 54 seconds. There is one other section of the code NFPA that talks about calculations for a dry system and has longer times for various hazards. Subsection states A system meeting the requirements of this section shall not be required to also meet the requirements of  Does a system in a residential condominium need to have a 15 second limit for water to reach the test connection of as stated in or could it have longer times like are shown in table


My second observed detail is that it took 1.75 hrs to restore the system to normal air pressure 50PSI in this case. states restoring normal air pressure in the system is limited to 30 minutes. My take is that this system is not compliant with the code for restoring air pressure and I think it is non compliant with the time it takes water to reach test connection.

Have I interpreted this correctly


Matthew Beck, PE