# Re: inrack sprinkler question

```I've seen in-racks that seem to be essentially a separate system as they
come off a common manifold and look like risers, and still calculate both
back to the manifold, adjust there and the calc out to the source.```
```

Ron Greenman

rongreen...@gmail.com

253.576.9700

The Universe is monstrously indifferent to the presence of man. -Werner
Herzog, screenwriter, film director, author, actor and opera
director (1942-)

On Fri, Feb 23, 2018 at 10:44 AM, Bob <b...@firebyknight.com> wrote:

> Timothy,
> The in-rack demand is added to the ceiling demand at the point of
> connection
> to the system.  Also, the pressure is to be balanced to within .5 psi.
>
> From the 2013 ed.:
> 23.8.2   Water demand of sprinklers installed in racks shall be added to
> ceiling sprinkler water demand over the same protected area at the point of
> connection.
> 23.8.3   The demand shall be balanced to the higher pressure.
> 23.8.4   Water demand of sprinklers installed in racks or water curtains
> shall be added to the ceiling sprinkler water demand
> at the point of connection. Demands shall be balanced to the higher
> pressure. (See Chapter 8.)
>
> 23.4.2.4  Hydraulic Junction Points.
> 23.4.2.4.1   Pressures at hydraulic junction points shall balance within
> 0.5
> psi (0.03 bar).
> 23.4.2.4.2   The highest pressure at the junction point, and the total
> flows
> as adjusted, shall be carried into the calculations.
>
>
> Thank you,
>
> Bob Knight, CET III
> 208-318-3057
>
> -----Original Message-----
> From: Sprinklerforum [mailto:sprinklerforum-bounces@lists.firesprinkler.
> org]
> On Behalf Of Easter, Timothy M CIV NAVFAC MIDLANT, CI
> Sent: Friday, February 23, 2018 11:30 AM
> To: sprinklerforum@lists.firesprinkler.org
> Subject: inrack sprinkler question
>
> Does the in-rack sprinkler system need to be combined with the ceiling
> sprinkler system, for hydraulic calcs? Can anyone cite reference that
> requires this?
>
> V/R,
> Timothy M. Easter, P.E.
> NAVFAC Mid-Atlantic
> Capital Improvements
> Fire Protection Engineer
> Comm: (757) 341 - 0130 / DSN 341 - 0130
> Office Hours: 0800 - 1730
> RDO: 2nd Friday
>
>
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