Sure Reza, wish I could have helped. My knowledge of the European Code is limited to the interesting differences Europeans vs. Americans via the Excellent summary Damien Shannon provided me off Forum a few years ago. I love both!, and one of the things that stuck out was the 'two calc' regarding tank capacity. I know Chris Cahill (American Forumite) is aware of it :)
Brad . On Jan 30, 2017 4:12 PM, "Reza Esmaeili" <[email protected]> wrote: > Brad, > Thanks for your comment. It's not about water tank storage. It's about > considering the maximum flow at the area closet to the pump just in order > to select the right pump. Check this figure in VdS CEA 4001 Standard: > > http://www.sarian.ir/Pump-Curve.png > > Best, > Reza Esmaeili > > Email:[email protected] > Cell: +98 912 2444875 > Web: www.sarian.ir > > -------------------------------------------- > On Tue, 1/31/17, Brad Casterline <[email protected]> wrote: > > Subject: RE: Selecting a Fire Pump/ Europeans vs. Americans > To: [email protected] > Date: Tuesday, January 31, 2017, 1:03 AM > > Isn't > the requirement for calculating the area closest to the pump > only when the water supply is water storage tank, to verify > the tank capacity against flow rate and duration? > > You are right though - American codes do not require the two > sets-- we calc 'most remote' and use that size all > the way back because the closer you get to the riser the > more you will be flowing, hence the concern about tank > capacity. > > It is a can of worms that has not yet been opened here in > 'the states'. > Brad > A 1000 > GPM rated pump will not likely produce a flow rate of 1800 > GPM. It will limit out most likely around 1650 to maybe 1700 > GPM. It should then, nonetheless provide the minimum design > density at the lest demanding design area. There is no code > requirement to produce the maximum flow capacity of a design > area, only the minimum. > > Mark at Aero > > 602 820-7894 > > > > -----Original Message----- > > From: Sprinklerforum [mailto:sprinklerforum- > [email protected]. org] On Behalf Of Reza > Esmaeili > > Sent: Monday, January 30, 2017 1:56 PM > > To: sprinklerforum@lists. > firesprinkler.org > > Subject: Selecting a Fire Pump/ Europeans vs. Americans > > > > I am glad to write in this nice forum again! > > > > I don’t understand NFPA 20 for selecting fire pump: > “Maximum system demand flow should be between 90% and 140% > of pump’s rated capacity, but, in no case, greater than > 150% of the pump’s rated capacity”. > > > > That is to say if my total sprinkler and hose demand is > 1400GPM, I can simply choose a 1000GPM rated pump. 1400GPM > is calculated based on the most remote sprinklers, so what > if the sprinklers nearer to pumps are activated and my > demand jump to 1800GPM? Then at high flow, there is a > possibility for cavitation and overloading the motor. Am I > wrong? > > > > Europeans calculate differently. They calculate the demand > both at the most unfavourable area (most remote area) and > most favourable area (near the pump). For example if they > calculate 1400GPM at most unfavourable and 1800GPM at most > favourable area, then based on these figures they choose a > pump. They also check 1800GPM on the pump curve to be sure > it’s less than 140% of rated capacity and also less than > 16m NPSHr. > > > > VdS CEA 4001 Standard in Europe: The pump set shall be > capable of providing at least the flow and pressure of both > the most favourable and the most unfavourable areas. The > maximum flow demand (Qmax) for supplying the most favourable > area may exceed the permitted rate by up to 40 %. The > pressure shall not fall by more than 30 % (of the pressure > prevailing with the permitted rate). The flow demand for the > most unfavourable area shall fall below the permitted rate > at all times. > > > > NFPA 20 and VdS are somehow the same. They limit the maximum > flow demand up to 140% of rated capacity, but Europeans > really calculate the minimum and maximum demand and check > this is less than 140% but American don’t check anything. > So if like the above example an American designer make a > tight selection (Choosing a 1000GPM pump for 1400GPM > demand), is there any possible problem if the sprinklers > near the pumps are activated and the pump runs at > 1800GPM? > > > > Best, > > > > Reza Esmaeili > > > > Email:[email protected] > > Cell: +98 912 2444875 > > Web: www.sarian.ir > > ______________________________ _________________ > > Sprinklerforum mailing list > > Sprinklerforum@lists. > firesprinkler.org > > http://lists.firesprinkler. > org/listinfo.cgi/ sprinklerforum-firesprinkler. org > > ______________________________ _________________ > > Sprinklerforum mailing list > > Sprinklerforum@lists. > firesprinkler.org > > http://lists.firesprinkler. > org/listinfo.cgi/ sprinklerforum-firesprinkler. org > > > -----Inline Attachment Follows----- > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler. > org > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler. > org >
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