Float valve not closing every time

[JohnDora]

The valve for my WTC is like the small drum held on to the WTC by a rubber band in the picture. It doesn't always seal meaning my U-boat doesn't always surface efficiently.


So any guidance on cleaning or making it seal would be welcomed!

Thanks!

John

[type7]

I just put a cylinder together and am wondering if the valve needs to be at a certain orientation.

[He Who Shall Not Be Named]

I just put a cylinder together and am wondering if the valve needs to be at a certain orientation.

The manufacturer can give you a proper answer to those questions. I can't make out anything from your photo.

David

[redboat219]

That's an R & R Model Engineering WTC by Ron Perot in the UK.

I inquired about this particular piece of hardware and he kindly answered

" the snorkel device is in fact a vacuum break valve and simply allows the negative air pressure within the ballast tank to equalise upon surfacing. The pump fills the ballast up to the horizontal baffle plate only and any excess is pumped out of the valve and the model can then submerge. When surfacing the pump is reversed and pumps out the water creating a partial vacuum with the ballast tank, once the valve breaks surface it opens to allow pressure to equalise."

it's like David's float valve but instead of a flapper valve
a small buoyant ball resides inside the cylinder.

Have you tried operating the boat with the valve removed?

[rwtdiver]

John,

Its very similar to the 70mm and the 80mm WTC that is for sale on Nautilus Drydocks. I had a few issues with mine and I removed the vacuum break valve and ran the tube up through a brass tube on the sail!

Rob
"Firemen can stand the heat."

80mm Diameter, Dual Shaft Watertight Cylinder | Drydocks (rc-submarine.com)

[redboat219]

I just put a cylinder together and am wondering if the valve needs to be at a certain orientation.

[redboat219]

[RCSubGuy]

The valve obviously needs to be oriented in such a manner that the ball floats to seal the intake when the boat is submerged. So.. vertically oriented, hose on top. If it's not sealing fully, disassembling the valve and cleaning the ball and ball seat may be in order. Lots of crud floating around in lakes and ponds. It doesn't take much to break that seal.

[JohnDora]

Thanks Gents - some good advice!
I'd like to avoid disassembly as that would require some minor surgery on the innards of the conning tower. Any advice for chemicals I could use to dissolve perhaps what is organic matter stuck on only a part of the floating ball would be great! I don't know what it is made from so don't want to use something like acetone or white spirit that might compound the problem.

[redboat219]

Dishwashing soap?

[He Who Shall Not Be Named]

Thanks Gents - some good advice!
I'd like to avoid disassembly as that would require some minor surgery on the innards of the conning tower. Any advice for chemicals I could use to dissolve perhaps what is organic matter stuck on only a part of the floating ball would be great! I don't know what it is made from so don't want to use something like acetone or white spirit that might compound the problem.

You put the thing in that sail. You take it out. Welcome to the reality of r/c model submarine operation, maintenance and repair.

You either maintain your gear -- and that means knowing how to take it apart and put it together again without winding up with mystery parts still on the workbench -- or you don't.

R/c submarines are not plug-and-play foamy RTF airplanes! If you're doing it right your toy submarine will demand about three-hours of maintenance/repair/test/adjustment time for every hour of in-water play time.

Get that snorkel on the bench, take it apart -- learn a few things along the way -- and clean the seat and ball. Duh! The only solvent you want to attack this thing with is water (the universal solvent on this planet) ... and maybe a touch of soap. A little alkali never hurt no one!



David

[JohnDora]

You had me laughing there!

Of course you don’t know me. I am entirely capable of taking things apart - and have repaired a few clocks for example - but having spent an entire career involved in building and maintaining big infrastructure and having cut my teeth on ancient railway engineering I always seek (what I call) the lazy way first!

One motto I use - “Always have a Plan B in the back pocket”.

[He Who Shall Not Be Named]

You had me laughing there!

Of course you don’t know me. I am entirely capable of taking things apart - and have repaired a few clocks for example - but having spent an entire career involved in building and maintaining big infrastructure and having cut my teeth on ancient railway engineering I always seek (what I call) the lazy way first!

One motto I use - “Always have a Plan B in the back pocket”.

OK then. Credentials presented. Get to it.

[Subculture]

I've not got one of these vacuum breaks, but I recall Ron saying they're not designed to have a perfect seal, else they wouldn't relax once the device was above the water. The idea is that any gap is small enough that the pump can empty the tank faster than any leakage past the vacuum break.

[He Who Shall Not Be Named]

I've not got one of these vacuum breaks, but I recall Ron saying they're not designed to have a perfect seal, else they wouldn't relax once the device was above the water. The idea is that any gap is small enough that the pump can empty the tank faster than any leakage past the vacuum break.

With Ron's ballast sub-system If there is not a leak, a tight vacuum will keep the ball up tight onto the seat and it'll never admit atmosphere to displace water in the ballast tank during the 'blow' phase. With his snorkel, the ball and seat present a lot of surface area -- and the force of any significant differential between the ballast tank and atmosphere will keep the ball locked in place -- to work, this arrangement must 'leak'. Keep in mind that the force presented to the valve elements is proportionate to the seating surface area of the ball and its seat (or, in my case, the nipple and rubber element).

With the SAS ballast sub-system, I elected to make it a tight one. That's why the snorkel and safety float-valve floats are weighted, and the nipple inlets where they meet the rubber element are only .025" in diameter -- such a small surface area to the sealing rubber element presents little retaining force as a consequence of differential pressure, which permits the float (with attached rubber element) to drop once water is not there to buoy up the float. I rely on gravity to pull the float down, opening the valve, not a leak somewhere on the induction side of the ballast sub-system to eventually drop the differential to the point where the ball (in Ron's arrangement) will unseat.