Questions surriounding the use of Tyco's AP sprinklers

[SprinklerDesigner2]

Last time I had a project dealing with sprinklers in attics was before the AP sprinkler made it's appearance.

Application: The Use of Specific Application Sprinklers for Protecting Attics

Tyco did a pretty good job laying out the details except for a few areas where I am still a little confused and looking for confirmation.

Question #1: I'm 99% sure I understand what direction the measurement of "12 feet perpendicular to slope" is but not 100% sure. Do I have the 10' and 12' maximum dimensions correctly aligned with the slopes? Generally I am pretty good at visualizing things but on this one I've developed a mental block or something.

Question #2: I know what stagger is but is it defined? On FIG. 7J - CALCULATION 1 the AP sprinklers in the hip are supposed to be staggered but aren't.

Question #3: Is there a minimum distance between AP sprinklers when AP sprinklers are on different planes of the hip? I wish Tyco included samples with some actual dimensions.

Question #4: So many of their figures indicate AP sprinklers throughout the hip but then some indicate SD sprinklers on one side of the hip which which I feel is the only way to go with this type of cut down roof truss. Can you think of a construction where AP sprinklers would be called for on both sides of the ridge line in lieu of SD sprinklers on one side when utilizing cut down trusses?

On the patent Combustible concealed space sprinkler system and method

They seem to be indicating a line of sprinklers very close to the ridge on one side?

 

[cdafd]

1. Read the many pages of obstruction rules and make sure the installers know them

2. What you see on paper does not always happen in the field, as you know, there will be adjustments in the field.

3. I think the ap head allows baffles, would have to pull up the spec sheet

 

[SprinklerDesigner2]

cdafd,

Yeah, all 92 pages of them.

I didn't see anything about baffles and I am wondering if something similar to the 1/4" plywood baffles used on COIN sprinklers would be acceptable?

On the patent page they had circles... seems to me laying these heads out with overlapping circles wouldn't be more appropriate but that isn't my decision.

Also hearing your comment about field adjustments... it isn't a perfect world and we've all seen our installers do things that makes the hairs stand up on our backs which makes me wonder what I haven't caught.

 

[cdafd]

Make sure you have the most current sheet, date on yours is 07, may be a more current one.

 

[SprinklerDesigner2]

I saw that as well and looked but that is the one on Tyco's site.

I am looking at a two story project with real lousy water: 44 static, 11 residual @ 711 gpm. Now that is lousy!

Obviously I am going to need a fire pump to do anything at all but Georgia is strictly enforcing that 20 psi minimum suction pressure with the pump flowing 150% of it's rated capacity so I would like to use a 200 gpm pump.

With a 200 gpm pump I won't have any worries about suction pressure but if I use a 250 gpm pump my suction pressure drops to around 24 psi at the pump suction flange. This makes me nervous.

If I understand this right my total water required should be well under 300 gpm but I got to make sure.

 

[cdafd]

Also check page 7 of 28

Ap heads require 60 second trip no matter what

Assuming you are doing dry system for the attic heads

 

[cdafd]

Not sure if this answers one of your questions


BB, SD, HIP, or AP Minimum Dis- tance Between Sprinklers:
4 feet (1,2 m) as measured along branchline for BB and SD (Ref. Figure 3).
3 feet (0,9 m) as measured along branch line for HIP (Ref. Figure 12).
7 feet (2,1 m) between AP Sprinkler

 

[cdafd]

2013 version

http://www.tyco-fire.com/TD_TFP/TFP/TFP610_11_2013.pdf

 

[cdafd]

Question #2: I know what stagger is but is it defined? On FIG. 7J - CALCULATION 1 the AP sprinklers in the hip are supposed to be staggered but aren't.


you are looking at three different slopes.

For AP, the maximum spacing is 10 feet (3,1 m) perpendicular to slope and 12 feet (3,6 m) parallel to slope. When there is more than one row of AP Sprinklers, the sprinklers must be staggered per Figure 20-B-3.

 

[cdafd]

Question #3: Is there a minimum distance between AP sprinklers when AP sprinklers are on different planes of the hip? I wish Tyco included samples with some actual dimensions.


I would go with the seven feet


Question #2: I know what stagger is but is it defined? On FIG. 7J - CALCULATION 1 the AP sprinklers in the hip are supposed to be staggered but aren't.

maybe the aps are just shown for reference

 

[cdafd]

don't know if the spray patterns on page 3 help you much::::

http://tyco-fire.com/TFP_common/AtticSpecApp2.pdf

 

[SprinklerDesigner2]

Not sure if this answers one of your questions

BB, SD, HIP, or AP Minimum Dis- tance Between Sprinklers:
4 feet (1,2 m) as measured along branchline for BB and SD (Ref. Figure 3).
3 feet (0,9 m) as measured along branch line for HIP (Ref. Figure 12).
7 feet (2,1 m) between AP Sprinkler

That is relatively simple and straight forward but when we start mixing

to me it can get a little complex.

Using AP sprinklers the ridge on the hip is supposed to be treated as if it were a wall so do we keep heads a minimum of 3'-6" off the hip ridge?

As far as spacing and calculations go I find it pretty basic to understand but I can see a lot of issues around the seams of peaks and ridges especially when mixing different heads.

Am I making a mountain out of a mole hill?

 

[cdafd]

For ?-2

BB, SD, HIP, or AP Minimum Dis- tance Between Sprinklers
4 feet (1,2 m) as measured along branchline for BB and SD (Refer to Fig- ure 3).
3 feet (0,9 m) as measured along branch line for HIP (Refer to Figure 12)

 

[cdafd]

For ?-1



BB, SD, HIP, or AP Minimum Dis- tance To AP Sprinklers or Standard Spray Sprinklers
As measured along the peak/ridge di- rection (Refer to Figure 4), 6 feet (1,8 m) from BB, SD, and HIP to Standard Spray Sprinklers.

 

[cdafd]

Waiting for Stookey to jump in

Problem is looks good on paper, but due to const, and installation have never seen a perfect plan work out with these heads, normally have to field adjust when you get heads close

 

[cdafd]

Using AP sprinklers the ridge on the hip is supposed to be treated as if it were a wall so do we keep heads a minimum of 3'-6" off the hip ridge?


I want to say no, but nothing to back it up right now.

But to reduce amount of heads , might start at 3'6"

 

[cdafd]

have not seen this before::::

NOTE: Use of the 4.2 K sprinklers in dry pipe systems is permitted by section 8.3.4.3 of NFPA 13 (2007 edition) where piping is corrosion resistant or internally galvanized.