Architectural Designs

How do I choose the flow rate for a pump in sprinkler system? For example 400 GPM @7 bar.kzaman07@hotmail.com?

I am new in this field of sprinkler system installation in UAE. I am looking for several answers which are not clear in my mind. Finally I am knocking at your door for help. Could you please answer me the following questions: 1. How do we choose the flow rate for a pump in sprinkler system? For example 400 GPM @7 bar. From where I will get this GPM? 2. For designing a sprinkler system what area we must consider. For example in a commercial building of 3 floors we have 500 sprinklers from which about 160 sprinkler per floor. Should we take all 500 under considerations? Or how I will have to proceed for designing? Should I take the areas of all floors under consideration? Looking forward for your reply. Kind Regards Kamrujjaman

Public Comments

1. 1) GPM = gallons per minute Basically I think you need to size the pump on the number of sprinklers you expect to use at a certain time. I presume there'll be a building standard somewhere that specifies what flow rate you need from a sprinkler. From the link...... A standard quick response sprinkler head usually discharges about 13 -18 gallons of water per minute. Studies have shown that a single sprinkler head can extinguish many common residential fires in about four minutes. A wide majority of residential fires only activate one or two sprinkler heads. Early extinguishment of fires also limits smoke and heat damage as well. So if we take a mid range value of 15 gallons per minute (GPM), a 400 GPM pump will be able to supply water to about 27 sprinklers at once. 2) You could design for the worst case scenario, in which case you'd have to consider all 500 sprinklers going off at once, but that would have to be a pretty catastrophic fire. I'd imagine it would be more likely to consider a fire in a certain area, add a safety factor of say 8 times the area (imagine a square area and 8 identical areas around it making a 3x3 grid) You'd also have to consider whether to have localised sprinklers that are started by the heat from the fire, or an area system where all the sprinklers around the area are triggered from a central control panel. You'll also need to consider what sort of fire will be generated. If there is a lot of flammable material then that will mean a big fire spreading quickly so more water will be needed. In an open plan office where, for example, a computer starts burning then more localised sprinklers and control will be needed.