Calculating ESFRs with less than 3 branchlines 1

[Cidona]

Dear Forum.

I'm looking at a storage occupancy which is protected with ESFR sprinklers. The room is a long narrow room and the branchlines are running the length of the room. Due to this configuration there is only 2 branchlines with ESFRs. The adjacent room is a Ordinary Hazard occupancy.

Since the 4 ESFR sprinklers on 3 branchlines cannot be calculated (as there are only 2 ESFR branchlines), should this (a) be calculated with 6 sprinklers on each of the 2 ESFR branchlines (b) just calculate 4 ESFR sprinklers on the 2 branchlines (so only calculating 8 sprinklers) or (c) do I have to calculate the 4 ESFR sprinklers on each of the 2 ESFR branchlines and then also include some of the Ordinary Hazard area sprinklers (if so what parameters should be used for the adjacent sprinklers...)?

There is another room that is protected with a single branchlines of ESFRs.

Your insight would be greatly appreciated.

Damien Shannon

 

[SprinklerDesigner2]

My gut tells me to go with 12 sprinklers 6 on a branch line. Fact is the more I think about it I think that is the only answer.

 

[Cidona]

Thanks very much for the response SprinklerDesigner2!

I think the 2 x 6 would have been my approach also, however I'm looking at these drawings for others and would have liked to be able to point to something in the book stating such. What would your thoughts be on the room with a single branchline?

Thanks again and have a Happy New Year!

 

[SprinklerDesigner2]

What would your thoughts be on the room with a single branchline?

Happy New Year everyone!

To always play safe. With a single line of 15 years I'd calculate 12 and with a total of 11 sprinklers on a line I'd calculate them all.

I am proud to say I have been a layout technician for over 40 years now and I think the biggest thing I've learned is to always play safe and never cut corners.

I'll give you an example of how I operate.

90% of the pipe we purchase is 2" and 4", we purchase by the multiple truckload with terms paid in cash at the time of order placement. Before the trucks roll in it's our pipe and it's all been fully paid for in cash. Oh my, how we can beat up suppliers would amaze you... I want 100,000 feet of 2" sch. 10 pipe and I'll write you a check today if you get me a good price. It really is amazing; I've purchased 2" sch. 10 cheaper than I would 1 1/4" Sch. 10 on the common market buying one or two bundles.

I just did a 54,000 sq ft store all of it with 2" lines and 4" mains. I know I could have made a 1 1/4" grid with 3" mains work but 2" and 4" is what we had so that is what the owner got. The owner also got himself a 35 psi safety factor but oh well... I sleep better at night and when you're approaching 70 (sob) that's worth something. The fight is gone from me so fights is something I go out of my way to avoid.

 

[Cidona]

Thanks again for your input SprinklerDesigner2.

Would seem the correct way to go to me also - allowing for the same size fire as the 'default calculation' and since that can''t be achieved in the regular shape that the fire would spread length ways. Just wish there was wording in the book to instruct all to follow also.

Thanks again and all the best in 2016!