Thread: pump advice needed please

Originally Posted by maninblack

hi
can anyone pleas etell me of a pump which is needed for a ballast tank will pump in and out (fill and empty)
preferably one which can be submerged...tank is roughly 3ltr capacity..
many thx
maninblack

What is the application, what is the power source, how quickly does the transfer have to be, is out door or in door?

If the purpose is for flooding ballest tanks in a model boat(size dependant) 12v bilge pumps for a runabout or yacht would do the trick for emptying, flooding could be done with another pump wired to do so. Or you could make your ballest tank air tight and use a compressed air tank to pressurise the tank an force the water from it, as used in a submarine.. but if you run out of air and your vessel is too far from land you might end up with an unintentional submarine.chris

hi
the tank will be air tight the idea is to fill with water for extra ballast to submerge then empty to surface again
cheers
mick

Have a look here about Ballast Tanks and how wich one could work
Submarine Technology..
Starting with a test about cummbag Ballasttanks arround next week..maybe able to tell you more than
What kind of Sub are you planing?
I will start with a Robbe Seawolf somehow next two weeks and maybe with a second one selfbuild (Explorertype) out of plumbing materials (deep diving static ballastsystem )
With my gumbagtest I try a robbe 6-12V waterpump first ..(cheap)
here is a dealer in germany who does Ballastsystems and got good looking Pumps as well Modell-Uboot-Spezialitäten
A pump has to be bidirectional and should not let water through if it stands still..otherwise you need a valve as well
Hope I was able to help you!
(sorry for my english I am a german living in england)
Uwe

A 3 litre tank is going to take a loooooooooooong time to fill with a peristaltic pump unless it's a very large.

You would be better served pumping into a vented tank using centrifugal models like a Reich or whale pump. Fit two, one to pump each way. You can always add a smaller trim tank, say 10-155 of the capacity of the main ballast tank , and that could be sealed, baffled and fed via peristaltic pump.