FEATURES 17
• Rotodynamic pumps use motion . This motion generates energy in the rainwater , and this causes it to move along the pipe . These kinds of pumps usually need a motor to turn the device that increases the pressure on the rainwater , or to increase the flow rate using centrifugal force .
• A centrifugal pump is suitable for most rainwater harvesting applications because of its relative simplicity , range of head and flows , as well as its relative low cost . A centrifugal pump consists of a motor , pump casing and impeller . The pump casing holds the impeller and channels water to and from the impeller . Centrifugal pumps are used to transport fluids by the conversion of rotational kinetic energy to the hydrodynamic energy of the fluid flow .
• The on-demand pump makes sure that the water to a tap or irrigation system stays pressurised . They have built-in sensors that can tell when the pressure drops so that the pump can start up . They are on the more high-end side of the scale , but if your client wants something to be on all the time , this is the type of pump to look at .
• A transfer pump is one of those that you plug in when you need it . They do not run constantly , and they have to have water moving through them while they are on so that they don ’ t overheat . They are more affordable but do require your clients to flick a switch to switch the pump on or off as needed .
Both the on-demand and the transfer pumps can either be submersible or surface pump . This all depends on the design of the pump . Submersibles go into the water storage tank , while surface pumps are usually mounted to something like the water tank on the outside .
The submersibles often come with the added benefit of being able to shut the pump off if the water level drops too low because they have built-in dry-run level protection . They also stay hidden , aiding those clients who are looking for something aesthetically pleasing
A DAB pump system . while the external pumps are outside the tank . For those clients who go for external pumps and who still want things to look pretty , the external pump can be hidden in a hole or under a cover so that it won ’ t stick out .
There are some things to take into consideration before choosing a pump . “ Pumps ensure you have the pressure you need all the time ,”
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