Standpipes in other then high rise - Georgia

[SprinklerDesigner2]

I've got a four story building motel that requires a standpipe (the top floor is 34' above lowest level of fire department access) but I don't want to use a fire pump.

5-7* Minimum Pressure for System Design and Sizing of Pipe.
Standpipe systems shall be designed so that the system demand can be supplied by both the attached water supply, where required, and fire department connections. The authority having jurisdiction shall be consulted regarding the water supply available from a fire department pumper.
Standpipe systems shall be one of the following:
(1) Hydraulically designed to provide the required waterflow rate at a minimum residual pressure of 100 psi (6.9 bar) at the outlet of the hydraulically most remote 21/2-in. (63.5-mm) hose connection and 65 psi (4.5 bar) at the outlet of the hydraulically most remote 11/2-in. (38.1-mm) hose station.
Exception No. 1: Where the authority having jurisdiction permits pressures lower than 100 psi (6.9 bar) for 21/2-in. (63.5-mm) hose connections, based on suppression tactics, the pressure shall be permitted to be reduced to not less than 65 psi (4.5 bar).
Exception No. 2: In other than high-rise buildings, the authority having jurisdiction shall be allowed to reduce the minimum pressure requirements of this section if the building is protected throughout by an approved automatic sprinkler system.

For exception #2 who would be the authoriity having jurisdiction? Is it the building code or local fireman?

 

[TravisMack]

SD2:

Think MANUAL WET standpipes. You will have a pump. It is the responding pumper truck. Check with your AHJ, but they will likely be able to provide 150 psi at 1000 gpm from the pumper truck. Calc your sprinkler systems to the city supply. Calc your standpipes to the FDC.

I do some work with a contractor in GA and they had never considered a manual wet standpipe. I educated them on it. They went to the fire dept all is well. Again, you still have to calculate it to provide 100 psi per NFPA 14, but the supply is the pumper truck.

 

[PEDARRIN2]

The building code official is typically the authority having jurisdiction with a caveat.

A lot of the designs I have seen, the building code official requires the fire chief of the answering fire department to make this call for him because the fire department are the most familiar with what equipment they have and what will happen on the site.

In some of the designs I have seen, the fire department doesn't want to depend on the water supply to provide 100 psi at the top. They only want to know that the pressure and flow will be enough to supply the sprinklers. When they get to the scene, they hook up their truck to supply the standpipes (if their trucks can supply the pressure - otherwise it is up to the water supply pressure or pump.)

We have gotten away with not having a fire pump in these situations since we did not have enough pressure to have 100 psi at the top. When this happens, you have a manual wet system instead of an automatic wet system.

Hope that helps.

 

[stookeyfpe]

Pedarrin 2

I disagree with this being a building offical decision. It is not in jurisdictions that adopt the International Building Code and the International Fire Code. The requirement for construction permits (and approval) rests with the Fire Code Official.

SD2, talk to the FD. It is there decision. The other item to bring up when discussing this with the FD is reduced reliability of the system by requiring a NFPA 20 fire pump. One can argue that the reliability of a pump on a engine is more reliable than one in a building is maintained to a higher degree because of all the nonsprinklered buildings and exterior fires the FD responds to. A fire pump in a building is required to be maintained in accordance with IFC Chapter 9 and NFPA 25, but we all know this is dependant on the owner's understanding of these systems and there committment to regulatory compliance.

 

[SprinklerDesigner2]

Travis,

We learn something new every day. Check this out!

http://www.inscomm.state.ga.us/About/Rules.aspx?T=Div1

http://www.inscomm.state.ga.us/ANNOUNCEMENTS/1056AR-1302007151339.pdf

Special to Georgia 120-3-3: State Minimum Fire Safety Standards - effective 02/01/2007

Found at the top of page 25.

http://img514.imageshack.us/img514/6848/georgiastandpipekl5.jpg

 

[TravisMack]

That is crazy that they don't make you calc the pressures if you use 8" pipe. I guess that by making everything 8" pipe, you are pretty much guaranteed to get 100 psi at the top outlet when using 150 psi at the pumper connection. However, I would hope you don't use just a standard 2 way FDC when doing the "manual" standpipe. I always use at least a 3-way FDC, and almost always have 6" connected to it.

T

 

[PEDARRIN2]

Stookeyfpe,

I would agree that this decision should not be made by the building code official unless he has the necessary knowledge/experience/authority to make this decision. Most would and should defer to the fire code official.

But sometimes the building code official is who signs the paperwork - if the powers that be determine that the fire code official reports to him. He may not know what he is authorizing, but he has the experinced person whom he relies upon to make the right decision.

 

[SprinklerDesigner2]

"I would agree that this decision should not be made by the building code official unless he has the necessary knowledge/experience/authority to make this decision. Most would and should defer to the fire code official."

I liked the way it was accomplished under the old Ohio fire code.

In Ohio the plan reviwer had to be a professional engineer but the wording was "The plan reviewer shall confer with the fire official in the placement of hydrants, standpipes and fire department connections."

Four sets of drawings were submitted to the plan reviewer who would forward one set to the local fire department asking them to review the locations of fire hydrants, fire department connection and standpipes if one was involved. After the review the fire official would approve his set or voice his objections not to me but the plan reviewer.

This worked well allowing the local fire department to have input while keeping them out of the layout and design side of things which most know just a little about.

Ah, to live in a perfect world.

 

[PEDARRIN2]

SD2

You are right that it was a lot easier under the old Ohio Codes.

I have found it is wise to be in contact with the local fire department during the design phase.

They have the knowledge of what type of fire department connection (wall or free standing, connection size and type, etc.) should be used.

They also have knowledge of what pumper capacity they have so you know whether you are going to be required to have 100 psi at the top of the standpipe. This often will tell you if you need a pump or not.

They also will tell you whether you have to follow the code and place the fire department valve at the intermediate landing or at the floor level.

If I waited until plan review for these questions to be answered, I would be gambling with a lot of potential change orders.

The local fire department may or may not have the "authority" to approve plans but the guys in Columbus or the local AHJ usually let them have what they ask for because the local fire department, not the AHJ nor code official in Columbus, are the ones who will be answering the fire alarm.