Is Pipe An Obstruction to In-Rack Sprinklers?

1/21/2020

Does anyone have any literature on the installation of face sprinklers (the sprinkler along the first row of a rack on the "face" of the rack)?

I have an AHJ who is saying that the height of the pipes serving the face sprinklers must not meet the definition of "hindrance" or "obstruction" in the building code.

The face sprinklers in my situation are placed on first row of a rack system with the face sprinklers of the upright type. (2015 NFPA-30 16.5.1.10 (6)). The sprinkler line is located parallel with the face of the rack. The bottom of the pipe is 4"-6" below the bottom of the rack.

I have checked for the definition of what he mentioned and I can't find anything in the building codes. Building code is 2015 IBC/IFC. Also checked the NFPA-13 handbooks but the installation requirements are concerned with sprinkler deflector versus the piping itself. Thanks in advance!

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James Phifer

1/21/2020 11:16:14 am

If the piping is 3" or larger, then I think your deflector will need to be on a minimum 12" sprig.

NFPA13: 2016 edition
8.6.5.2.1.8 The requirements of 8.6.5.2.1.3 shall not apply to
sprinkler system piping less than 3 in. (80 mm) in diameter

sean

1/21/2020 11:52:02 am

agreed. being in a rack or not the pipe would be a potential obstruction.

John M

1/21/2020 02:55:44 pm

The sprinkler piping in question is 1.5" in size and along the face of the rack placed within the rack itself. In order to get the upright heads the 1.5"SP line is a bit lower to allow for the nipple and the upright head. Now the inspector is coming back and stating that the sprinklers are obstructed by the rack itself. My understanding is that these sprinklers should not follow the same obstruction rules as ceiling sprinklers. The in-rack sprinklers serve to protect the racking system and to oppose the vertical spread of fire.

Franck

1/21/2020 03:56:48 pm

You’re right, you don’t need to consider the obstruction from the pallets (otherwise you need a minimum distance of 18 in. between deflector and top of storage and does not make any sense)

The purpose of the face sprinklers is to avoid the aisle jump (which happens with height of storage above 25 ft) and the water is sprayed between the rack and on one face of it (thus the name « face sprinklers »)

But there is still an obstruction to consider : the rack structure (horizontal and vertical). If the sprinkler is located too close to the rack metallic structure, it can create an obstruction. Be particularly attentive to the vertical metallic « beams »
To avoid the problem with the horizontal ones, heads are located a little bit inside the racks.

This is why you need your face sprinklers at least 3 in. from rack upright and 18 in. maximum from the aisles.

John

1/23/2020 09:14:19 am

Thank you Franck!

Is Pipe An Obstruction to In-Rack Sprinklers?

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