Pumps and Stored Water Supplies 1

[AdamMurray]

Currently have a client who requires a stored water supply. Typically would recommend vertical turbine fire pump and cistern. However, the architect would like to have the stored water supply installed adjacent to the basement (burried underground), and have the fire pump installed in the basement.

I have seen this type of installation in some older buildings, using a horizontal split case pump. Is anyone familiar with this type of set up.....would you be concerned with zero suction or priming of the pump?

Any information would be apreciated.

Regards
Adam

 

[dangnm]

Per NFPA 20, you can go to -3 PSI on the suction of a fire pump when taken from a tank. Depending on the structural conditions, could you consider a tank by Xerxes. They are fiberglass tanks that can be buried underground. If you work with the Structural engineer and Xerxes, they can make the tank to work with the building foundation. You put the tank so that part of it is under a corner of the basement. You then install a vertical turbine pump taking suction from the fiberglass tank.

Your other option is to have the "standard" underground tank stored close to the basement wall and then have a line from the tank go directly to the suction line of the fire pump.

Either option will meet all of the requirements of NFPA 20.

Please email or post if you need any further clarification.

T-Mack

 

[jonelv]

If the pump is below the water level in the tank then you can use a split case so if the pump room floor is at the same level as the tank base you should be OK as BWL should be about the impeller level. If there is a static lift involved then you can't use split case (NFPA 20 3.1-2). Vertical turbine pumps are normally used with below ground tanks but this requires prime mover / gearbox directly above ie sitting on roof of tank.

Some insurers eg FM Global also have particular requirements concerning what is acceptable or not and you should check out the specific data sheets as well as NFPA 20.

jonelv

 

[Slowzuki]

Adam Murray, there are some good resources on this site.

Ken Macfarlane