Did someone ask for a fire fighter / AHJ opinion ???? ........ Thoughts on the FDC thread in no particular order: - Yes, the code does create the concept of supplemental and I dont dispute how it is generally read or applied in the field but when was the last time any job went perfectly according to code & Hoyle ??? The same can be said for a fire scene .... no cookbook operations and very few cookie cutter solutions. - In the real world the variables are aplenty with what can go wrong in an emergency. There is a legacy of large loss / closed valve fires and no point in naming them, albeit a reality no matter how much we try to achieve with locks, chains, cable, and supervisory switches. In a perfect world I'd be quite the happy fireman if an FDC had to connect to the back end of a cross main. No valves could ever be in my way to pump that system up, up, and away and interruption of primary supply, fire pumps, and most other contingencies would not preclude full blown FD support at and above system demand designs. - In that same real world however we must consider muti-riser systems .... They are the way of design for large buildings, big box retail, and mixing wet pipe and dry piped systems in one building with one city main. As a rookie in fire school we are taught about how to operate in a sprinkler protected occupancy ..... for exactly 30 minutes in the classroom and an hour on the drill ground where we all get drenched and enjoy chocking a flowing 1/2" head. Did someone say this was a good idea ??? Somewhere in that process I remember being told that the FDC is always after the valve so you can always support the system even if it was turned off. Hey great idea ..... except the instructors probably never heard of a multi-riser system. It's a very real possibility that a closed valve at the base of a riser can prevent FD support via FDC to a system. - Speaking only from my state there are specific cases where the FDC is intended to be the primary support to a system in both sprinkler and standpipe occupancies. This is often done in retro-fit applications and was part of the legislative incentive to push through retro-fits while keeping costs manageable. Hence in more advanced FF training programs and in my little fire company a building with an FDC is handled differently and without fail the first arriving pump apparatus goes to the FDC with a supply line from a city hydrant. In reality the fire department doesnt know or remember which systems are designed which way ... they still rely on being able to deliver the water regardless of all other possibilities. - I have also been to the universal training class where FF are told to supply an FDC at 150 PSI, push to 175 if there is confirmed extending fire and you arent seeing any control of the fire. Sounds easy enough .... but I dont really know if thats gonna prove out in the real world. I'm a little up in the air on the check valve may or may not close theory and havent found a training site yet where I can actually test the theory. I also havent found a training site with a fire pump to test the same kind of theory and will the pump preclude 'FDC supplement' or will it actually comingle the two sources. Anyone have a building owner willing to let us try ?? Have fire truck ... will travel ...... - I think one of my reputations includes the 'anti-siamese inspector' label. I often times request a triamese or quadramese on projects where the system designs exceed 500 GPM. I also pushed water up a hill on a high-rise project to get a quadramese for the standpipe system under the theory that if the building fire pump fails then my engine becomes the source .... can your fire pump supply a 750 GPM standpipe requirement through two 2 1/2" hoses ??? If yours cant then how can mine ... especially when the pump is at the base of the riser and m engine is 300 feet away in the street out front. I have been successful but I also know somebody somewhere in the project is thinking money going down the main drain. All in all I guess its possible to say I am over-applying the intent of the FDC when I review a system. Under the same logic most fire departments are over-applying the concept of contingency on a non-sprinklered building fire when they commit additional engines to other water sources and hydrants in case the main engine pump fails or is somehow interrupted. The designers put plans on paper .....The installers put systems in buildings....The fire department puts people in the buildings ---- Somewhere in that equation belongs some consideration to getting the most into a system when the worst can be happening. As always I appreciate the forum for bringing the ideas and discussions together .... and I also appreciate the use of the soapbox. Dave P. AHJ most days .... FF every night _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum
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