Centrifugal pump restricted output

[Dan Steill]

I uploaded the data sheet... Let me know if you need anything I can provide.

Preparing figures on what it is going on...

 

[Dan Steill]

Weight 600lbs
8ft by 4 ft
Flat bottom with 2ft taper bow.
2" draft.

This a test platform boat.

 

[Tom.G]

Weight 600lbs
8ft by 4 ft
Flat bottom with 2ft taper bow.
2" draft.

Hull Area = 32 sqft
Displacement = 32/6 = 5.3 cu.ft.
Weight of Water = 62 lbs/cu.ft
Weight of Displaced Water = 62 x 5.3 = 329 lbs
Looks like your Draft will be around 3.6 inches.

 

[Nidum]

I was hoping for a proper technical data sheet . One with pump performance characteristics .

Without this information we don't know the relationship between pump delivery pressure and flow rate . We could make some guesses based on known performance of similar pumps but I'd rather have solid data to work with .

Go to the actual manufacturers site and see if there is anything useful there .

 

[gmax137]

7.5hp. 100m³hr flow rate. 4 inch inlet. 4 inch outlet. ~50 psi

Pardon my units, but ...
100m³hr = 440 gpm
50 psi * 144/62 = 116 ft
water horsepower WHP = QH/3960 = 440 * 116 / 3960 = 13 BHP (assuming 100% eff.)
so you see, the listed 7.5 hp doesn't correlate to the flow & head. You really do need the pump curve from the manufacturer to begin. Plus as mentioned above, it will show you the head vs flow.

 

[Averagesupernova]

The way I see it is that you can estimate performance based on this: I have used a 10 HP Johnson motor on the back of a small boat and to use something that is only 7.5 HP and guaranteed to be less efficient will probably get you down to a performance that would be similar to sticking a 3 to 4 HP outboard on the back. To stick a trash pump on a boat and expect much is foolhardy. Not to say that it would never move a boat, I am sure it would. We get results in several ways in this world. We go on prior established research of others in the form of specs and etc. which involves some math and other skills that we may or may not have, or we just try stuff.