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FIRE SERVICE AND GENERAL FIRE SAFETY TOPICS => Technical Advice => Topic started by: clio222 on January 25, 2011, 01:06:45 PM

Title: Sprinkler Clearance
Post by: clio222 on January 25, 2011, 01:06:45 PM
Hi I realise this is a very big subject however my question is this:

Within my workplace we have a number of small storage rooms of various sizes in order to ensure correct function of the installed sprinkler system ( ceiling heads ) we would like to enforce a minimum clearance distance between the stock within the rooms and the sprinkler heads. I have came across all different figures depending on what the stock is.

Can any one provide some advice/guidance I have trolled through BSEN12845 although it is quite a comprehensive document

Much appreciated
Title: Re: Sprinkler Clearance
Post by: kurnal on January 25, 2011, 02:28:50 PM
Take a look at section 12.1.2. page 75.
Generally its 500mm for OH and 1000mm for High Hazard and ESFR.
Title: Re: Sprinkler Clearance
Post by: clio222 on January 25, 2011, 03:10:16 PM
Hi Kurnal Thanks for the reply

12.1.2 A clear space shall be maintained below the deflector of roof and ceiling sprinklers of at least:
a) for LH and OH:
0,3 m for flat spray sprinklers;
0,5 m in all other cases.

I did come across this however the wording  below the " deflector " left me rather confussed ??

excuse my ignorance and I to assume that the deflector & sprinkler head are the same

Much appreciated
Title: Re: Sprinkler Clearance
Post by: AnthonyB on January 25, 2011, 03:30:39 PM
I would say that the deflector is the plate that spreads the water stream after it leaves the head

|______|  - where the head screws into the pipe
   /    \
  |      |    - arms with bulb/fusible link in
   \     /
     \ /
   |___|     - deflector plate

so that you measure clearance from the appropriate point.

Title: Re: Sprinkler Clearance
Post by: John Webb on January 25, 2011, 05:16:59 PM
Sprinklers can be pointing up (Upright) or down (Pendent) so there can a significant difference in the position to measure distance from. As it is the deflector plate that spreads the spray that's why measurements have to be made to it. The clearances are to ensure the spreading water from a head is not intercepted by the stored goods before it has finished spreading, if you follow me!
Title: Re: Sprinkler Clearance
Post by: clio222 on January 26, 2011, 03:18:58 PM
Thanks for the advice/guidance

Much appreciated