Question: 12 volt dc bilge pump 70lpm 4200lph?

(Posted by: kensmith1981 on 2009-07-30 08:30:32)

Hi i have a 12v dc bilge pump and i am wondering can it be used to run a sprinkler? as i have a 250 litre water tank out in my garden and i want to use this pump to run 1 sprinkler here is the specs of the pump - it is a marinepet brand bilge pump model no BL- 2512I 12v dc, Current 5.4amp, 4200 LPH OR 70 LPM , head max 4m , it also has a 1 inch outlet i also have a 240v 800w garden water pump used with my 250 litre water tank but i need to know will the bilge pump be fine? as my 240v 800w pump is playing up a bit as my 240v 800w pump is playing up a bit

Posted by: ricsudukai on 2009-07-30, 09:32:15

It works fine to a point, I wouldn't use it for hours, say ten or fifteen minutes at a time unless a heavy duty type. Iv'e got one lying around somewhere that was used in a pond for years to run a little waterfall. A commercial power supply of around 10 amps @ 13.8 V didn't get hot and the pump seemed real happy. They don't last long blocked with weed or running dry though. The biggest problem lies in using smaller diameter hose - the pump loses a lot of capacity and the current goes up dramatically as the pump is straining against the restriction. An in-line pump, such as a galley pressure pump will be much more efficient in that case. So if you use larger hose (poly pipe is cheap), and a low pressure sprinkler set-up (say two or three sprinklers off a common "T " or two "Y "s into 1/ 2 " pipe so the restriction is minimal) the bilge pump will work happily.

Posted by: jtexas on 2009-07-30, 08:50:06

Don't know anybody that's tried it, but a good quality bilge pump is pretty reliable, they're made to function under adverse conditions. Hard to predict whether you'll get enough water pressure for your application. Give it a good 12.6 to 13 volts and be sure to fuse it according to manufacturer specs, or else it will burn up if it gets obstructed. An inline fuse holder should work fine.

Posted by: TechnoStuff on 2009-07-30, 13:39:08

I'm sure someone will correct me if I'm wrong but... 4M max head would translate to about 5.7psi. This is much too low to operate a garden sprinkler properly. 70LPM is quite a bit for a sprinkler, I had measured one of mine and thought it to be about 20 LPM or so, obviously it would depend on the sprinkler. Your pump is obviously well suited to pumping the bilge where there is little pressure (head) and large volume is a plus, doesn't appear to me to be well suited for watering the yard unless you had a number of sprinklers grouped together since they wont spray far. Perhaps the restriction of feeding it to a single sprinkler would cause it to create more pressure but above 4M head, you are probably going to overwork the motor.