Pressurized water pump ballast systems

[subshop]

re:surflo pump

scott, do you have a model # for that surflo pump? neil

[tmsmalley]

Looks like an RV water

Looks like an RV water pump. They are pretty large -

[spitfiremk3]

Hi...

Some close up pics of the pump... You should be able to read the model # from the first pic... if not let me know and I can print it out.
THANX
Scott

[spitfiremk3]

And by the way... You

And by the way... You could cut the feet off the pump and mount it with a couple of band clamps to reduce the size a little if need. I believe this pump would fit in just about any 1/32 size boat.
THANX
Scott

[crazy ivan]

Does anyone know how to

Does anyone know how to make a GOOD valve (open and closed) that will take 40PSI? I am presently looking at 12v soleniod valves. They cost more than the pump....

Scott, here is one from McMaster Carr (http://www.mcmaster.com/) that won't break your bank. I used one for the same purpose in my Fulton Nautilus.

"7877K55
(Same as 7877K5)
Polypropylene Solenoid Valve Wire Leads, 1/8" NPT Female, 150 PSI, 12 VDC
In stock at $22.56 Each"

[anonymous]

Hi Scott,

Can you reverse that

Hi Scott,

Can you reverse that pump i.e pump out as well as in?

David

[anonymous]

http://upload5.postimage.org/293752/Pinchvalve.jpg

Hi Scott,

I suspect that you



Hi Scott,

I suspect that you are not going to like this but a pinch valve on a silicone rubber tubing has a lot going for it ]http://www.subcommittee.com/forum/icon_biggrin.gif[/img]

David

[spitfiremk3]

Hi Dave...

No, I don't believe the pump pumps in reverse. YOU DON"T NEED A PUMP TO GET THE WATER OUT OF THE TANK AT 40 PSI!!! I like your homemade valve but will the silicon tubing hold up to 40 PSI... I will have to experiment. The best idea I like is a 12 volt solenoid valve. I think but I am not sure, that I will need one with a bigger orifice than 1/8 inch. The tubing I have now is 3/8 inside dia. So as small as a 1/4 inch would probably work. I can go smaller than the 3/8 becuase I don't need to dump the tank (56 fluid ounces)in like a few seconds. Is there anyone out there using a 1/8inch orifice size solenoid valve in their sub?
THANX
Scott

[spitfiremk3]

To Crazy Ivan... How big

To Crazy Ivan... How big is your Nautilus? How many ounces in the ballast tank? The hose I am using has an inside dia of 3/8 inch. Do you think 1/8 (orifice in the solenoid valve) is big enough for a 56 oz tank?
THANX
Scott

[anonymous]

Hi Scott,
I somehow thought that

Hi Scott,
I somehow thought that you would like a solenoid valve!
Not all the parts for model submarines are available at your local hardware store - some you need to design and build. Please try the pinch valve it does not take long to put together. BTW do you understand my point about having a valve that does not provide a perfect seal?

Also I don't think you have quite got the idea about how a pressure tank system works. Before you start to pump you have a tank containing air at atmospheric pressure. You start to pump and the pressure rises to ,say, 40psi. You open your discharge valve and the pressure drops back down to ATMOSPHERIC pressure. At this point THEORETICALLY the tank will again be empty.

PRACTICALLY the last bit of water is expelled very slowly because you don't have much pressure difference to blow it out. Also any air losses (see previous posts) mean that your tank still contains SOME water. This water level builds up as you do repeat dives. (See previous posts)

Hence it is an advantage to have a reversible pump and this can often pull a slight vacuum in the pressure tank to ensure that you have maximum buoyancy. It also speeds coming back to your proper waterline.

So Scott, sorry to labour the point but you did ask for help and believe me we do have a lot of experience of operating this system in the UK. (I was running my Charlie class sub this morning which uses this system, in fact.)

Phew!!! I think I have said everything I can on this system now so Iwill stop posting in this thread before it becomes a text book Please do ask me privately if you would like any further help.

David

[crazy ivan]

Scott,

My Fulton's hull is 25

Scott,

My Fulton's hull is 25 inches long x 7 high x 6 wide. The ballast tank is around 14 oz., which at 7 psi will take on roughly 7 oz. of water. It will empty in about 20 seconds or less from the compressed air. At 40 psi, I would expect even your 56 0z. tank would empty pretty quick even with a 1/8 orifice. Experiment a bit and find out. If it's too slow, McMaster also shows some delrin valves with 1/4 and 3/8 orifices for $37.82

Consider, however, what you are going to accomplish. If you are trying to simulate a modern nuke's emergency blow, then yes, you want to dump the tank as quickly as possible. If you are emulating a WWII U-boat or Fleetboat though, these subs, even though they could crash dive in 30 seconds, did not come to full surfaced waterline all that quickly. They would typically blow in just enough high pressure air to come up to decks awash. The German boats would then blow the tanks empty using the exhaust from the diesel engines. The US boats (then and now) incorporated low pressure blowers (10 psi) to complete the operation. So surfacing was not all that fast.

[spitfiremk3]

Hi Folks

Hi... Today I got my 12 volt solenoid valve, $19.00 delivered from E-Bay. I have not tried it yet but it should work AOK... If it dumps the tank to quickly I will make a simple restricter for the line. It is a diaphragm type valve. I will keep you guys posted in the future when I get the boat up and running, on how well the system works. So far I have around $95.00 in my ballast system (less the electronic switches). I do want to thank Davy for showing me his homemade "pinch" valve as I believe it would work too but I am trying to build as few as possible parts. As I am buried in work on this boat now... So long as I can keep the total price of the boat as low as possible.
THANX
Scott