Sorry about the double dip (replying to myself) but I wanted to say thanks for the png Reza. I'll need a day or two to understand it (i might be slow but i make a lot of mistakes)
Brad . On Jan 30, 2017 5:01 PM, "Brad Casterline" <[email protected]> wrote: > 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 <(602)%20820-7894> >> >> >> >> -----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 <+98%20912%20244%204875> >> >> 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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