Are these magnetic drive pump specifications realistic?

[CopperCone]

I like the little giant magnetic drive pumps but their pressure is very low.

I am looking for high corrosion resistance.

I want something capable of maybe 30 lpm at 50 psi or about 120 head.

I would like it to be cheap and driven by a 90vdc motor.

I figure thisdoes not exist. I believe i am mechanically capable of connecting a pump to a motor of my choice by a belt. I would actually prefer this because i can isolate motorheat and cool things better.

Is the pump part realistic at least? All the magnetic drive pumps i see have pressure thats like less then 10 psi.

Are these requirements insane?

[Conrad Hoffman]

120 what of head? mm, you're OK, miles, you're in trouble. Just guessing, the coupling is good, but it's still a centrifugal pump and is going to have trouble getting high pressure. You might be able to work out the capacity based on HP. Maybe you could run two in series?

[CopperCone]

120 feet, 50 PSI, 40 meters

My suspicion is that i need a gear pump.

[Conrad Hoffman]

Based on some online calculators, those numbers suggest you'll need about 12 HP!

[CopperCone]

Based on some online calculators, those numbers suggest you'll need about 12 HP!

Can you link what you used?

It's a shame, https://www.grainger.com/product/DAYTON-Rotary-Gear-Pump-6DHH9 only 1/3 HP.. but its a cast iron gear pump

[Ian.M]

50 PSI is fractionally over 35 m of water head (assuming pure water @ 1 Kg/l)
30 l/m is 0.5 l/s so 0.5 Kg raised 35+ m every second.   From P=M*g*H, that's slightly over 172 Joules/sec of useful work done.   As a properly matched impeller pump typically has an efficiency in excess of 50%, 345 W mechanical power should be sufficient provided the pipe diameter is large enough that frictional losses are slight.  A 1/2 HP motor and pump should handle it.

However, with the exception of positive displacement pumps,  flow and pressure tend to be quoted as limiting values, flow at zero head, so minimum back pressure and pressure at zero flow.  Therefore you need to be starting your search of pump catalogs with ones rated for about 100 PSI and 60 l/m

[Conrad Hoffman]

Yeah, that 12 HP number seemed really high. Comparing this to my basement sump pump, the pump is 1/2 HP and is rated for (converted) 242 lpm at 3 m lift height.

[tecman]

30 l/m ( 8 GPM) at 50 psi is 0.23 HP, w/o pump efficiency (P * Q / 1714 = HP).  So slightly over 1/4 HP is all you need.  A centrifugal can give you these requirements.

paul