Flexible coupling for fire pump suction pipe

[DavidCR]

Does anyone know what are the requirements for flexible couplings used to protect the suction pipe of fire pumps.?

A vendor is supplying one (10")of the type that consists of a flexible hose covered with a stainless steel wire mesh, I don´t have the technical data of the coupling, but I wanted to know if somebody can comment what are the permitted types of flexible couplings or its requirements, on NFPA 20 it only says that it must be used, but I haven´t seen about it specific requirements.

Thanks a lot.

 

[gouveia]

I would argue that the flexible coupling is not required per NFPA 20. The only section that I am aware of in NFPA 20 that references flexible couplings on the suction/discharge piping (not the drive shaft/exhaust/fuel etc) is section:

5.27 Earthquake Protection.
5.27.4 Where the system riser is also a part of the fire pump discharge piping, a flexible pipe coupling shall be installed at the base of the system riser.

I would also make the arguement against even installing the "wire mesh" hoses per NFPA 13 paragraph:

6.1.1.2 "Unless the requirements of 6.1.1.3, 6.1.1.4, or 6.1.1.5 are met, all materials and devices essential to successful system operation shall be listed."

I am not aware of ANY wire mesh hoses, other than Metrafelx which is for a different application, that are LISTED for use on a sprinkler system. But I am interested to learn if someone has finally had their product listed. That being said I have seen lots of government specs that require these devices and have just put them in to make the client happy. Let us know what you learn.

 

[TravisMack]

I have seen these used a lot when you have a water storage tank that is on a different foundation than the pump room. I don't believe it is UL listed for fire protection use, but it is frequently done.

 

[cdafd]

DavidCR what section are you referencing and what year book????????

 

[alpo0]

DavidCR,
If the installation is in earthquake zone you need a flexible coupling at the top and at the bottom of any riser (NFPA 13 1999 6-4.2). The fexible coupling is a flexible coupling not a flexible hose! See Victaulic Style 77 Standard Flexible Coupling

http://www.victaulic.com/inCommerce/detail.asp?prod_id=144&site_id=1&page_id=77