Question Function dump valve drysuite

[grantmac]

In the open position it's just a one-way valve and should take very little pressure to activate. Pull one out and blow in it: takes almost nothing.

The more spring pressure you add the more it acts like an OPV. Which is really just a one-way valve with a set point for pressure release.

 

[Kofferfisch]

My conceptualization of the force differential that causes the dump valve to open is the buoyancy of the air. I would think of this force in terms of a vector force (air wants to go up to the surface) and not difference in scalar force (atmospheres / BAR). But it’s been about 25 years since I took physics.

Yes exactly that is what I think happen. At the end, technically speaking, the force of the buoyond air also generate a pressure when pushing on the surface of the opening mechanism. But not because in the suit is an over pressure.
Maybe your explanation helps others to understand my question better. Thank you.

I know that's a bit picky, but if you want to understand something exactly then that's necessary.

 

[rjack321]

Yes preasure is not even ditributed which im aware of. When the air is "transferd" to a different, for example a higher position, in the suit the volume is expanding (p*V=const). So no overpreasure is generated if i dive with a "normal" filled suite. Which force opens the valve when at the valve is no preasuredifference. Because to get a preasure difference the suite must be filled like a baloon in my oppinion.

If you stand vertically on the bottom, air will come out the shoulder valve or the neck seal (or both). No ballooning required. Everyone is entitled to an opinion, that doesn't make all of them correct.

 

[crofrog]

the upward force of the bubbles buoyancy exerts a force on the valve spring that allows gas to vent until the upward force on the spring matches the downward force on on the valve by the spring