What is the hydraulically most demanding area and why?

[SprinklerDesigner2]

System has two different areas.

Area #1 requires 345.5 gpm @ 71.2 psi at base of riser
Area #2 requires 341.1 gpm @ 72.1 psi at base of riser
Hose stream are 250 gpm for each area.

 

[SprinklerDesigner2]

In other words what one should be used on the hydraulic placard?

 

[stookeyfpe]

SD2

Oh the humanity. Can't you just put SYSTEM 1 & 2 on the hydraulic nameplate and call it good? Realistically, the difference is so small that its futile.

Are you going to tell use that the fire code official is requiring both? Please, no AHJ bashing....

 

[LCREP]

WOW so the person taking the water test had calibrated gauges AND it was done at the highest possible demand for the past 365 days??

My point, does it really matter which one you use? I would be happy that u plan for a hydraulic placard on the riser! In NJ most times we never find them. When I teach classes to AHJ's I always tell them if they do nothing to enforce the code AT LEAST make sure they hang the placard!

 

[gouveia]

We are missing the information on water supply to answer the question. Which calc is most demanding could vary depending up on if the water supply curve was extremely STEEP or extremely FLAT. I think the most demanding calculation is the one with the least pressure cushion.

PS - I agree with everyone else in that it is a non-issue

 

[SprinklerDesigner2]

No, no, noo... Stookey whatever gave you the idea I was the sort to beat up on local officials?

Sure, I agree it is a non-issue but here's the point.

I have a grid that isn't uniform and HASS will only peak uniform grids. So I peaked it by hand, built the sytem myself, assigned nodes, input pipe and "stepped" open heads across the grid to find my most remote area.

14.4.4.2* Gridded Systems.
14.4.4.2.1 For gridded systems, the designer shall verify that the hydraulically most demanding area is being used.
14.4.4.2.2 A minimum of two additional sets of calculations shall be submitted to demonstrate peaking of demand area friction loss when compared to areas immediately adjacent on either side along the same branch lines, unless the requirements of 14.4.4.2.3 are met.
14.4.4.2.3 Computer programs that show the peaking of the demand area friction loss shall be acceptable based on a single set of calculations.

When the grid is non-standard HASS will not automatically peak correctly.

Since I have to submit a minimum of 3 sets what area is the most remote?