Flow rates?

[KH971]

Roger, i was told to ask this question here. How does Tunze come up with their flow rates? I just look at the physical aspect of a large Sequence pump moving 5000 gal/hr and a Tunze Stream moving 5000 gal/hr ?

 

[rvitko]

Well, a sequence has a high head pressure so it is not on an equal footing, a 6200 can do 5200+ gph but it is doing it with virtually 0 head pressure, if you even put a couple feet of head pressure it would be practically no flow. What we do is put the pump at a very slight incline, so it is submerged and a pipe is coming off the end and pumping the water into a bag. We time how long it takes to fill the bag, weigh the bag and calculate out the volume. This tends to underrate the pumps because it does put a few inches of head pressure on them. Often people note a competitors rating may be equal but when they get the Tunze pump the flow seems to be much more. The competitors use a dye dispersion method which we don't particularly trust to be accurate.