There is a huge differnec between deluge valve and the on-off (wet type) valve. The wet type valve is normally used for buiding protection, and deluge valve is used for large area/equipment protection with open nozzles
Slowzuki
You 'r right. I means process type on-off valves which are not in UL or FM list. However, in term of realiability, they can do the same or better then a deluge valve.
I understand that NFPA does not state that deluge valve have to be hydraulic actuated valve. Therefore, we could use process on off valve instead.
I wonder if "9180" original question was about the need of deluge type valves, and why another type of valve (which may be listed) is not used. So I will add a new question (hope 9180 don´t mind)to complement the thread:
Is it permited to have a deluge system (open nozzles) with an on-off valve (a buterfly ULFM, hydralically and manually actuated, or an OS&Y gate valve for example) to supply the water?.
I have a case with open nozzles over an AST (tank) and we propose to control it with a UL-FM gate valve(OS&Y), we think the gate valve is simpler and the maintenance needs are less. The manual actuation is OK for the brigade. The system is NFPA 15 based, but we are not required for code compliance.