Here are specifications for two water pump sets. I would like to know which one will have more vertical suction.Pump 1:1.5 hp, 98cc Engine, 4 - Strokes RPM 3600 (Engine RPM), Petrol Fuel, Fuel Consumption 700 ml/hour, Delivery (horizontal) 50m, Inlet / Outlet Port (Dia) 1.5x1.5 inches, Output Capacity 48000 Litres / Hour.Pump 2:3.3hp, 163 cc Engine, 4 - Strokes RPM 3600 (Engine RPM), Petrol Start amp; Kerosene Run, Fuel Consumption 700 ml/hour, Delivery (horizontal) 26m, Inlet / Outlet Port (Dia) 2x2 inches Output Capacity 36000 Litres / Hour.which one should I go for.
Neither one if you are trying for more than about 32 feet (10 meters) because movement of water is determined by air pressure and the vacuum/suck and the former limiting. Pumps that move water vertically more that 30 feet or so PUSH the water. Which is why well pumps of any depth are hung on the end of the riser pipe with a power cable running down to them.
there is no way to tell from those numbers which one has more suction lift capacity. You would need the pump curves and see what the NPSHR is for each pump.
The first one appears to have a higher flow rating but neither gives a head figure, which is the maximum height it can work to above the pump. Lift from below a pump is limited to 32ft on any form of water pump; that is the limit water will rise to with a total vacuum above it. A normal pump cannot pull a perfect vacuum so working lift will be somewhat less. The practical limit depends on the pump head in use and it's actual head limit; the total height from the pickup point to the delivery point count as working head. Any kind of centrifugal pump or one which cannot also pump air perfectly will need a foot valve at the base of the inlet pipe and a priming system to fill the pipe and pump body with water before the pump is started. If you expect the water level to be more than 10 - 15ft down, you would be better off with a submersible pump; the only limit then is the head rating which can be just about anything. Get a suitably rated petrol or diesel generator as well (3x the pump power rating) if it must operate independently of mains power.
