Can a vane type water flow switch be located between the bottom of the DPV and the connection off of the wet system? See NFPA 13 section 3-10.2.4 and NFPA 72 section 3-8.3.2.4.1. I say it is a simple NO! No vane type flow switches are permitted on a dry system. But I'm getting the ever popular "we do this all the time in other jurisdictions". What do you think?
The argument I'm getting is that this is actually not on the dry pipe system, but on the wet system. That is where NFPA 72 comes into the picture. I believe it requires a separate pressure water flow switch to be installed on the DPV.
Section 6.6.2.2.2 of the 1996 "Where a dry pipe valve is located on the system side of the alarm valve, connection of the actuating device of the alarms for the dry pipe valve to the alarms on the wet pipe system shall be permitted."
