slurry pump gearbox

max head height

Understanding Max Head Height

It is the max height the pump can return water. A pump with max head height of 2 metres must sit no more than 2 metres below the tank.

Output Reduction

Output would be greatly reduced to almost zero at max head height.

Pump Specifications

The pump is adjustable from 1200-2300 lph and has max head height of 240cm. It's going to be more like 70 to 80 cm.

Flow and Head Height

Some have charts telling you what flow is at given head heights. Flow would be nearly 0 at maximum head height but the weight of water from tank will increase the flow a bit too so flow would be 0 @ 2.4m above water level , in theory, but thats not allowing for flow lost through media or dirty hoses.

Loop Setup

It's just a loop. It gos powerhead-->reactor-->full length spraybar.

Flow Rates and Practical Considerations

The quoted flow rates are normally at 0 head height. Manufacturer's saying that 2m is max head height means that if that pump's inlet is positioned 2 meters below the outlet, then it will have theoretically 0 flow at that distance. But that would be even less in practice, because it doesn't take into account the size of the hoses used, connector diameters, bends, obstructions/media, etc.

Head Height Definition

The head height is the maximum height the pump will pump to with zero flow, normally for aquatic pumps in 1-2 meter range. Size of pipe, bends, diameters etc doesn't make any difference to max head height there is no flow. Size of pipe, bends etc only makes a difference to the flow.

If you are making a "loop" with the pump, ie inlet and outlet are at the same height, as in an external filter, then max head height doesn't matter (as the head height is zero in this case) and what matters is the pumps maximum flow rate and number of pipe bends, corners, diameters etc.

Pressure and Pipe Size

The head height is actually the amount of pressure the pump can apply to push the water up. When you have a narrower than ideal pipe, the pump needs to put more pressure in order to push the water up, and in the same logic it needs less pressure with wider piping and no other obstructions. So a pump obstructed by narrower pipes, bends, etc.. will need to work harder to apply enough pressure and that will affect the head height/the vertical distance it can manage to push the water up to. Which of course in turn is another thing that adds to the pressure needed by the pump. The higher the head height, the more pressure needed by the pump to push water.

Basically they are all related and depend on each other for maximum performance.

Physics of Pressure

Pressure for a column of liquid is given by P=hρg. P=Pressure in Pascals, h=height in metres, ρ= density in Kg/m3 and g=acceleration due to gravity (10m/s2). No where in this simple equation is the size of pipe, bends etc needed. Doesn't matter if the pipe is 10cm in diameter or 4mm in diameter, or has 50 million bends in it the pump will only pump to its max head height given by P=hρg.

Optimal Hose Size

With friction drag the inner area of the pipe surface ratio to the volume rate of water flow is imp. This ratio is radius dependent. Most of our pumps are pressure head limited in the sense that the magnetic propeller can throw only a mam weight of water. Per unit time this weight of water depends on hose diam. So if you work out all details there is an optimal hose size for our pumps.