Fire Tank Vent Size

[Jeremiah187]

Gents,

NFPA 22 says fire water tank vent needs to be minimum of 2".

Somewhere (long ago) i've heard that the tank vent needs to be at least 1 pipe size larger then suction line to fire pump.

Does anyone have any additional information? Or heard of the same requirement.

This job in particular is northern canada.

 

[cdafd]

4.14.2 A vent pipe shall have a cross-sectional area equal to a minimum of one-half the area of the discharge pipe(s) or fill pipe, whichever is the larger.?????

 

[psafety]

Vacuum is a killer of tanks, tread carefully!

I first determine the MAV (maximum allowable vacuum), then I size a vent to admit air at the rate liquid can leave. Based on atmospheric pressure to the MAV pressure. I use the pumpout on the performance curves at the installed bhp -and- drain valves open. Many will think this is too conserative, but the cost of gooseneck vent is pennies. A collapsed tank is hundreds of thousands.

 

[ContractorDave]

Just curious but Northern Canada where?

Regards
Dave

 

[Jeremiah187]

Main Office is Yellowknife, but work includes everywhere from Alert to Iqualuit to Edmonton, Inuvik to Whitehorse....

 

[ContractorDave]

I just may be your next door neighbour!
Drive down into Kam Lake,right on Deh Cho Blvd, and first left is us. Small world.

Regards
Dave