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Flexible Connections Between Above Ground Water Tank and Piping

Flexible Connections Between Above Ground Water Tank and Piping

Flexible Connections Between Above Ground Water Tank and Piping

(OP)
When connecting piping (above ground) between fire pump suction and and an above ground water storage tank, it is required to have a flexible connection. I have yet to find a flexible connection pipe that is listed for fire protection systems. The size would be 8" or 10". Does anyone know of a listed flexible connection for this situation?

RE: Flexible Connections Between Above Ground Water Tank and Piping

Sorry, I meant "required by", not "supplied by"

RE: Flexible Connections Between Above Ground Water Tank and Piping

In California, eq area, a flex connection is required. Don't quote me, but I believe metra flex is one supplier.

RE: Flexible Connections Between Above Ground Water Tank and Piping

"metra-Flex" is a listed flexible grooved connection that I have used in the past at bldg expansion joints, floating dock separation, etc.

spkreng, CET

RE: Flexible Connections Between Above Ground Water Tank and Piping

Good day!

As per NFPA-20 clasue 4.14.6.5 - strain relief (like flexible connector) is required only where the pump and its suction supply are on separate foundations with rigid interconnecting pipe. Therefore, it is not always required to have a flexible connector.

BTW, i also used metraflex before in my previous project.

Hope it helps,

RE: Flexible Connections Between Above Ground Water Tank and Piping

An easy listed solution for pump suction, is to use a pipe spool with several flexible grooved joints in series (as Victualic´s Fig 77 with small nipples like Fig 43).

RE: Flexible Connections Between Above Ground Water Tank and Piping

FM requires a flex connection between a tank, and fire pump in EQ areas. After searching through NFPA 13, 20 and 22, I am not finding this criteria. Anyone know where this tidbit of info may be hiding? Or, maybe it is not addressed by NFPA?

RE: Flexible Connections Between Above Ground Water Tank and Piping

(OP)
Thanks for all the responses. This tank would be on a separate foundation with a heated connector building between the tank and the main building. With two separate foundations, as you would expect, there could be movement from settling that would cause the tank foundation and the building foundation to be offset slightly. We have used the metraflex joint in the past but have been told it is not technically "listed" for fire protection use. We could use multiple flexible couplings as has been suggested but we woould prefer a cleaner installation. It appears that the AHJ will allow the metraflex connection as long as FM Global will sign off on its use. Working on that now. Thanks again for your help.

RE: Flexible Connections Between Above Ground Water Tank and Piping

Mikes54, did you look at my question as well?

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