An idea for a vent valve

[Slats]

here an illustration to what I was proposing. Since the valve seat is outside there is no risk for air to get trapped underneath. the curved top of the ballast tank ensure air flows up.

what I was proposing was actually opposite to that - valve inside and attached to the screw head, closing on the up stroke.

[redboat219]

the valve must close on the up-stroke. Not the down-stroke.

Is there a particular reason why it should be that?

[Subculture]

When you pressurise the tank with propel, the valve will seal tighter preventing any chance of a leak.

[Slats]

When you pressurise the tank with propel, the valve will seal tighter preventing any chance of a leak.

Yes, and I would think the same would occur with snort air being pumped in too

But Andy I think what David is driving at here is that "the existing" SD mechanism seals the tank on the up stroke. Its a device that has a double duty in that when you blow the propel tank's blow schrader type valve the BT valve seals extra tight (upwards) making sure that the propel forces the water out through the free flood holes. The downstroke moves the activating propel arm away from the propel tank blow valve and corresponds with releasing the BT valve to allow the tank to be vented and thus allows free flooding of the tank.



J

[bassplayer1]

By the way, will something like this work or is it a stupid idea!

[Slats]

Looks big, heavy, cumbersome, and won't fit in the "current setup" as a simple modification.
J

[bassplayer1]

OK, I agree but will it do the job!

[redboat219]

Have you seen post #19 of this thread? My guess is it would. But I would suggest curving the top of the ballast tank to ensure air doesn't get trapped in the corners.

Check out this link I found over at another site. Scroll down to the bottom half and you'll see something similar to what I was proposing:wink:.

http://www.modelarstwopodwodne.hekko.pl/technika-modelarska/3-techniki-zanurzania-op.html

[bassplayer1]

Thanks a lot guys!!!

[oztruck]

[Slats]

I like your thinking.
Could you not eliminate the T pieces by having two outlets atop the ballast tank - one for the venting pump / one for the air in pump?
J

[oztruck]

I guess so John. I was thinking along the lines of less is more, the less holes we have to seal in the WTC the more reliable it is going to be. Because 99% of the time they will be pumping air a big failure at one of the "T"'s is not as bad as water getting in.

[redboat219]

how about just using a single pump to blow ballast but incorporate a "pinch" roller like those in water pump systems to vent air out of the ballast tank. This way vent is passive, less battery drain.

[oztruck]

Is the "pinch" roller type a one way pump (zero flow back)?

[Albion]

single pumps, menas a reversible switch or ESC, the twin pump system might be easier to configure when you look at the total package