Flexible couplings on CPVC passing through fire walls

[jkampana]

I have an AHJ that has stated the following in his review letter: "Since fire stopping is required when the pipe passes through the fire rated wall assembly. The piping passing through a fire rated assembly shall be provided with flexible couplings within 1 ft of each side of the wall." I asked for clarification and he said this provision is necessary even with cpvc branch lines that feed apartments units from the main corridor. I am aware that this is necessary as you pass through concrete walls but have never ran across this in Type V-A construction Apartments.

Is there any justification for this provision that I am not aware of?

 

[TravisMack]

Is your project a Seismic design category C or greater? If not, then seismic issues don't apply. Off hand, I believe the flex coupling within 1' stems from 9.3 which does not apply if you are are SDC A or B.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

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[jkampana]

It is a seismic design Category D. Seismic does apply. I am just not aware of a place even in 9.3 that requires flexible couplings on either side of a fire rated wall in type V-A construction. It has a requirement for concrete or masonry walls. I feel like this is just something the AHJ is making up. It will cost enough that it is worth fighting if he has no basis for his requirement.

 

[cdafd]

Have not read it::::

https://www.lubrizol.com/CPVC/Documents/White-Papers/Dispelling-Seismic-Myths.pdf

You can ask the ahi to show it to you have it and review it.

Plus you see if it is an adopted item

 

[TravisMack]

I would argue it in this manner:

9.3.2.3.1 The flexible couplings shall be installed as follows:
(1)*Within 24 in. (610 mm) of the top and bottom of all risers, unless the following provisions are met:
(a) In risers less than 3 ft (0.9 m) in length, flexible couplings are permitted to be omitted.
(b) In risers 3 ft to 7 ft (0.9 m to 2.1 m) in length, one flexible coupling is adequate.
(2) Within 12 in. (305 mm) above and within 24 in. (610 mm) below the floor in multistory buildings
(3) On both sides of concrete or masonry walls within 1 ft (305 mm) of the wall surface, unless clearance is provided in accordance with 9.3.4
(4)*Within 24 in. (610 mm) of building expansion joints
(5) Within 24 in. (610 mm) of the top of drops exceeding 15 ft (4.6 m) in length to portions of systems supplying more than one sprinkler, regardless of pipe size
(6) Within 24 in. (610 mm) above and 24 in. (610 mm) below any intermediate points of support for a riser or other vertical pipe

Then I would go back one entry in the standard and argue:
9.3.2.3 Systems having more flexible couplings than required by this section shall be provided with additional sway bracing as required in 9.3.5.5.9.

If you install this flexible coupling, which is clearly not required by NFPA 13, then you will be required to install a lateral brace within 24" of the piping as that is an additional flexible coupling above the what the standard requires. I would hope this shows him that he is not correct in requiring this additional coupling.

However, if you are dealing with a badge heavy AHJ, you may not want to show that section, because he could then argue for the flex coupling AND the lateral brace. At that point, you would have to go to the higher ups and try to get some one to see reason.

Some AHJs are completely unable to see reason. We have one in this area that requires 6" piping minimum for all combination standpipes. We have provided answers from NFPA, NFSA and AFSA all stating it is not required and can be 4" if calcs support it. Yet, they still hold to it because they rule in the kingdom. So, just be careful that if you are dealing with some one who can't reason, that argument could cost you even more.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

"Follow" us at

https://www.facebook.com/pages/MFP-Design-LLC/92218417692