Reversible Pump

[captain nemo12]

Hi guys,

I'm trying to duplicate the Sheerline diving system with my ballast tank. The system uses a pump that fills a ballast tank with water that compresses the air inside it and then closes a valve. To surface, you simply open the valve, letting the compressed air push the water out. Now here's my question, will the system work even though the pump is not reversible? Or do I need the added strengh of the pump to ensure a safe surfacing?

Thanks for any help!

[Guest]

If you place a one

If you place a one way valve in line with the pump, and place the servo controlled valve on a seperate line, it should work fine.

Do some experiments in the bath, you'll soon find out how well it works.

Make sure you baffle your tank well with this system.

Andy



Edited By Sub culture on 1147554533

[paul von braun]

Thats atall order youve set

Thats atall order youve set yourself - not impossible. I tried & failed...

[crazy ivan]

If you place a one

If you place a one way valve in line with the pump, and place the servo controlled valve on a seperate line, it should work fine.

That is exactly how I set up my Fulton Nautilus, and it works beautifully. No problems with the air space compressing with depth either, as would a bladder, so the system can work proportionally. I used an automotive window washer pump and found it will develop around 7 psi with my 7.2 volt system; good enough to surface from around 14 feet. The only drawback on my system is that at 7 psi, I can only about half fill the tank. If you can come up with a higher pressure pump, you could reduce the ballast tank size quite a bit, and increase your depth capability as well. I use an inexpensive pvc electric valve I bought from McMaster Carr.

[horribleharry]

good question! This may not

good question! This may not be TOO helpful but I'll tell you about mine...(at least as much as I know) I am running a high pressure reversible pump to my 2 stainless ballast tanks. I have been testing with this system but of course the one time I got to the lake to test, the ONE hose from the pump that was NOT clamped on popped off releasing the air into the tanks & surfacing the boat. It has been suggested to me to fit a one way valve to the system to facilitate quicker submerging (allowing the compressed air to escape) and using the pump to draw out the water from the tanks for surfacing. I will try this system, although I am wary of having a vacuum in the tanks in case there is a leak. (retrieving a 150 lb. boat is not on my to do list!) I unfortunately do not know the power of the pump as it's enclosed in ABS & I am not about to open it up to see how it works... I should though! What valve system are you using?
PM me if you like & I'll share what I can,
Cap'n Horrible



Edited By HorribleHarry on 1147568055

[captain nemo12]

Thanks for the response guys,

I

Thanks for the response guys,

I tested the pump via a hose in my bathtub, took no time in filling up the ballast tank. With the pump put in reverse, water took a couple of seconds to epmty out. I think I will make the pump reversible, the valve would be connected to a solenoid linked with the whole system.

[anonymous]

I use this system and

[color=#000000]I use this system and I reverse the pump to surface. (Pump and valve are in line i.e no bypass) It works well. A couple of things to watch]

[chuck chesney]

Why go through the worry

Why go through the worry and angst of the pump systems, with the problems that have been outlined above? It seems that a simple, straight forward, reliable ballast system, like RCABS (or RRCABS) would take the stress out of getting up and down in the water. Simple and reliable is better than a Rube Goldberg contraption that has multiple problems inherent in it's design.

[anonymous]

Please don't get that impression.

Please don't get that impression. It is a reliable, simple system used in many subs round the world.

Using a pinch valve also introduces an extra failsafe in that your sub will eventually rise again - even without any power from 30 feet or so.

It is just that Captain Nemo is developing it from scratch and needs a few pointers.

(I can't help smiling at that last sentence - I never thought that I could offer advice to Captain Nemo!)

David

[captain nemo12]

Please don't get that impression.

Please don't get that impression. It is a reliable, simple system used in many subs round the world.

Using a pinch valve also introduces an extra failsafe in that your sub will eventually rise again - even without any power from 30 feet or so.

It is just that Captain Nemo is developing it from scratch and needs a few pointers.

(I can't help smiling at that last sentence - I never thought that I could offer advice to Captain Nemo!)

David

David, thanks for the response!

I love building things from scratch, you get to learn how things works plus that great feeling you get when your creation works! (That is, if you did everything right! )

[anonymous]

Glad to be of help.

Another

Glad to be of help.

Another benefit of the system is that the tank is very simple - just a single inlet outlet pipe. If you make the tank close to the WTC diameter you can slide the tank easily to different positions in a single WTC to provide balance, fit equipment in etc - i.e it is very flexible.

Of course a bladder and air pump system is also quite flexible.

David