Gridded dry pipe systems 2

[ContractorDave]

13 sect 7.2.3.10 Gridded dry pipe systems shall not be installed. I assume this is because there are too many paths to a sprinkler, which would delay response time?

Have a great christmas all

 

[LCREP]

U would be correct, I think grids were OK up to the early 1980's. I still sometimes see old grid dry systems, and each time the trip times are in the 5-10 minute ++ range.

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Fire Sprinklers Save Firefighters’ Lives Too!

 

[stookeyfpe]

Ditto. I inspected a old gridded dry system in a refrigerated warehouse and it clocked 8:35 to get water to the inspector test connection.

Merry Christmas Tom and Dave.

 

[LCREP]

Scott,

Happy HO HO to you too,have a GREAT New Year, where did 2008 go to????

Tom

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Fire Sprinklers Save Firefighters’ Lives Too!

 

[SprinklerDesigner2]

2008 went where 2009 is sure to go.

I started designing sprinklers in 1976, all schedule 40 pipe having threaded fittings with 90% of the systems designed per pipe schedule, and sometimes I feel old looking at my first systems thinking "man, this pipe is old...."

I am going to hit the big six zero next week. Wife is already planning the party and I wish she wouldn't.

The NFPA book I used, I think it was 1974, was a little "red book" of about 120 pages.

I did a number of gridded dry systems in the 80's and the Ohio Fire Code at the time required all dry systems to get water in 60 seconds and doing this I learned some "tricks".

Keep the system small. No more then 200 to 250 gallons.

Use grids only on systems with high water pressures. You were asking for trouble where the water supply was 50/40 @ 800 gpm.

Accelerators on everything.

Connect the near and far mains with a cross main keeping all the mains at a lower elevation than branch lines. The idea was to fill the mains while trapping the air in the overhead branch lines.

Some people got crazy and had side feed grids with 600 gallons which is where you had problems.

Merry Christmas and happy new year to all!

 

[stookeyfpe]

SD2

I'm going to be in Atlanta next March doing a presentation at the SFPE educational seminar. I'm not sure where you are in relation to Atlanta. However, in the spirit of comradre, I would sure enjoy meeting you and enjoying some cornbread, sweet tea, and some form of dead cow or fish.

Stookeyfpe

 

[SprinklerDesigner2]

Stookey,

Between March 16th and 20th I'll be in Florida perparing for NICET test in inspections of water based systems.

As long as it doesn't conflict I would like to be there.