must be friday

[cdafd]

From some of the questions must be friday.

Thought in NFPA 13 or 24, that it stated underground cannot extend more than five feet into a building??

I know it says shall not run under foundation.

any help/ section reference, or is this just past prcatice that I have gotten use to???

 

[SprinklerDesigner2]

I really am beginning to hate Friday.

I never heard of the 5' restriction.

 

[cdafd]

SprinklerDesigner2

So how far would you allow an underground main to run under a building????????????

5ft

15ft

50ft

200ft
?ft

 

[SprinklerDesigner2]

cdafd,

If I had my way they underground would never be run under a building.

It might have been the Indiustrial Risk Insurers but I seem to remember reading an article where one of the largest losses they ever suffered in a sprinklered building is where an underground main came apart under the floor of a foundry.

Then again if I had my fire pumps would always be installed above grade on an outside wall and not in some back corner of a basement.

NFPA 24 "Standard for the Installation of Private Fire Service Mains and Their Appurtenances" - 2002 Edition

6.5 Sectional Valves.

6.5.1 Large, private, fire service main systems shall have sectional controlling valves at appropriate points to permit sectionalizing the system in the event of a break or to make repairs or extensions.

6.5.2 A sectional valve shall be provided at the following locations:

(1) On each bank where a main crosses water

(2) Outside the building foundation(s) where a main or a section of a main runs under a building.

10.6 Protection Against Damage.
10.6.1 Pipe shall not be run under buildings.
10.6.2 Where pipe must be run under buildings, special precautions shall be taken, including the following:
(1) Arching the foundation walls over the pipe
(2) Running pipe in covered trenches
(3) Providing valves to isolate sections of pipe under buildings

10.6.3 Fire service mains shall be permitted to enter the building adjacent to the foundation.

10.6.4 Where adjacent structures or physical conditions make it impractical to locate risers immediately inside an exterior wall, such risers shall be permitted to be located as close as practical to exterior walls to minimize underground piping under the building.

10.6.5 Where a riser is located close to building foundations, underground fittings of proper design and type shall be used to avoid locating pipe joints in or under the foundations.

A.4.1 Underground mains should be designed so that the system can be extended with a minimum of expense. Possible future plant expansion should also be considered and the piping designed so that it is not covered by buildings.

=============

So about as clear as mud. You can not but you can run pipe under buildings. I would jump up and down until I got an outside wall somewhere.

 

[TravisMack]

cdafd:

In cases where I can't get within 3' of the exterior wall, I have not had much heartburn as long as I don't exceed a length of pipe. I haven't often heard of ductile iron pipe splitting. But, it has been known to leak and come apart at the joints. So, I figure that if a length of pipe is about 20', if you put a joint at say 1' outside of the building wall, you could get about 19' into the building with a single stick of pipe.

If I have to put any more joints than the elbow up for the spigot, that is when I get concerned. Otherwise, if you are using a single stick of pipe, is there a real difference if you are 3' or 8' into the room?

Good luck!!

T