Does a trcuk rack system have to have an automatic deluge valve?

[rburrough]

We are designing a fire protection system for a new petroleum products terminal (gasoline, diesel, jet, #2 FO, MDO). We have a fire pump supplying water to a balanced pressure proportioning skid using 3% AFFF. The foam concentrate/water solution then runs to a buried manifold system where it can be directed to any of the tanks in the field, plus the truck rack loading area. The tanks have foam chambers. The truck rack has a sprinkler system and under carriage foam sprinklers.

My main question refers to the truck rack system. Does the system require a deluge valve? Can a sprinkler system be "dry" and have a normally open gate or butterfly valve on the manifold? The system will be automatic in that the fire detection system will start the fire pump and foam will be directed to the truck rack sprinklers automatically.

I haven't found a definitive answer in the NFPA codes regarding this particular foam sprinkler setup. Thanks for your help

 

[cdafd]

What if someone shuts the valve one day and no one knows about it??


someo reason besides money you cannot run a seperate supply line?? also if you have accidental activation may be easier to shut down if seperate system.

And if you have to foam a tank you have to remember to shut off the rack system or you will dump on it also.

Also not a foam person and have not seen a foam system in awhile, but concentraion is it the same needed for the tanks as for the loading rack???

 

[LCREP]

"The system will be automatic in that the fire detection system will start the fire pump and foam will be directed to the truck rack sprinklers automatically."

What happens if the fire pump starts for what ever reason, how many $$ of foam concentrate will be wasted not to mention down time( loss of business) of the rack while it is cleaned up.

Depending on a control valve to be open to permit the system to work properly when a flammable liquid is involved seems to me is a waste of a lot $$ should you get an event on the rack. I think you have significantly reduced the reliability of the foam rack system.

How much can a deluge valve compared to a OS&Y valve be in the budget of a large operation such as yours??


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Fire Sprinklers Save Firefighters’ Lives Too!

 

[rburrough]

Can a deluge valve operate properly without water pressure behind it? The system as designed is dry until the fire pump starts. I'm concerned about how the deluge would react to getting hit with a slug of water in both the case of the truck rack needing foam and in the case of a tank fire.

 

[cdafd]

stick it in the pump room???

stick it in a heated dog house

cannot answer if you say had a two hundred feet run of dry pipe before you hit the deluge and the pump kicks on.

check the pressure rating on the valve and call maker for advice.

 

[cdafd]

Just though normnally you have water to the bottm of the valve. You would have to check with the maker to see if it can be used/ set up dry below the valve.

 

[ryano669]

Most deluge valves are kept closed by a hydraulic priming line putting pressure on a differential clapper, or a mechanical lever. I have seen many systems trip after having pressure relieved under the seat, then re-pressurized before the prime line had a chance to fill.