Cutting a Divers Hose

[Sansho]

Eggcellent!

[Sasha_K]

Originally Posted by navyhmc

It depends. With the LP hose, if the regulator is balanced, it should leak out at the about the same rate. If the regulator is unbalanced, it is likely to leak out slower as the pressure will be closer to the water pressure.

Hm. Never thought about it that way. So, air would leak out faster on land then in water?

[navyhmc]

Air, because there's less resistance??????

[Sasha_K]

Originally Posted by navyhmc

Air, because there's less resistance??????

Not sure how to take your answer navyhmc :-)

[navyhmc]

It's a simple matter of density. Water is 50 times more dense than air so there is more resistance to an outward flow of air against water that resistence of air flow to air.

Think about this: As a kid, what was easier to blow bubbles in at McDonalds? A glass of soda/coke/pop or a freshly poured chocolate.strawberry/vanilla shake? Pop, as there was less resistance to the air. Now, with the shake, as it melts, the density decreases and it's easier to make sister annoying bubbles. Same with a cut hose.

That's my theory and I'm sticking with it!

[BSea]

Originally Posted by navyhmc

It's a simple matter of density. Water is 50 times more dense than air so there is more resistance to an outward flow of air against water that resistence of air flow to air.

Think about this: As a kid, what was easier to blow bubbles in at McDonalds? A glass of soda/coke/pop or a freshly poured chocolate.strawberry/vanilla shake? Pop, as there was less resistance to the air. Now, with the shake, as it melts, the density decreases and it's easier to make sister annoying bubbles. Same with a cut hose.

That's my theory and I'm sticking with it!

Actually, I think once you exceed the amount of pressure to to blow the bubbles, they would empty at the same rate. If it took 2 psi of pressure to blow a bubbles in the soda, and 10 psi to blow bubbles in the shake, but the straw was being pressurized to 135 psi, then the bubbles would be produced at the same rate till the tank pressure dropped to 10 psi.

But since air compresses much easier than water, the volume of air would double at 33ft to produce the same psi, the tank 2would empty twice as fast at 33 ft than at the surface, and 3 times as fast at 66 ft.

So I believe the tank would empty faster at depth just as breathing the air at depth empties the tank faster than breathing at the surface.

[ScubaToys Larry]

Actually, the difference at depth is negligible. Actually, slightly slower at depth as you have pressure trying to stop the air from escaping - but the differential between 15 psi and 60 psi is pretty insignificant when dealing with 3000 psi... So in tests that have been done, at 100 feet or so, it will take about 2-3 seconds longer to drain a tank with a cut HP hose... that's the only difference.

[BSea]

Originally Posted by ScubaToys Larry

Actually, the difference at depth is negligible. Actually, slightly slower at depth as you have pressure trying to stop the air from escaping - but the differential between 15 psi and 60 psi is pretty insignificant when dealing with 3000 psi... So in tests that have been done, at 100 feet or so, it will take about 2-3 seconds longer to drain a tank with a cut HP hose... that's the only difference.

Well I feel stupid. I was back looking at the LP. With the small hole in the HP fitting, you are only going to squeeze so many molecules through that hole at a time. Making the air denser doesn't mean the molecules are smaller, only closer together, so depth would have nothing to do with it once your pressure is so high that it doesn't allow amy more volume through the hose.

[plot]

Originally Posted by ScubaToys Larry

Actually, the difference at depth is negligible. Actually, slightly slower at depth as you have pressure trying to stop the air from escaping - but the differential between 15 psi and 60 psi is pretty insignificant when dealing with 3000 psi... So in tests that have been done, at 100 feet or so, it will take about 2-3 seconds longer to drain a tank with a cut HP hose... that's the only difference.

when every breath counts, that's a HUGE difference!

[Sasha_K]

Thanls Larry and bsea. I thought the difference would be bigger, but I guess not.

How about trying to fold the LP hose to prevent/slow down the air? Do you tihnk that's doable?

Man, this is calling for another video :-)