Why does a drysuit valve not leak water ?

[BlueTrin]

When I finish my dive there is some water in my wing because the dump valve let some water in.

What’s different with drysuit valves so that the air can come out but the water does not get in ?

 

[Storker]

Well, the drysuit exhaust valve has this little spring closing it against the water, while your inflator dump valve just opens wide when you press the thumb button. When you "open" your suit valve, you don't really open it. You just reduce the tension in the spring.

But it's not particularly uncommon to surface being somewhat wet on the left upper arm if you open your suit valve fully. So the DS valve can definitely let in water, too, if you let it. I always close my suit valve a click or three to avoid that. And I can still vent my suit by rolling slightly to the right and lifting my left elbow.

 

[BlueTrin]

Well, the drysuit exhaust valve has this little spring closing it against the water, while your inflator dump valve just opens wide when you press the thumb button. When you "open" your suit valve, you don't really open it. You just reduce the tension in the spring.

But it's not particularly uncommon to surface being somewhat wet on the left upper arm if you open your suit valve fully. So the DS valve can definitely let in water, too, if you let it. I always close my suit valve a click or three to avoid that. And I can still vent my suit by rolling slightly to the right and lifting my left elbow.

That makes sense: I heard for example that the old Apeks valve use to let water in if fully open for example.

Thanks for the explanation.

 

[W W Meixner]

When I finish my dive there is some water in my wing because the dump valve let some water in.

What’s different with drysuit valves so that the air can come out but the water does not get in ?

BT...

The water in your BCD is not coming in through the dump valve...this is a one way spring activated check valve...

When you exhaust air though your power inflator or by pulling the cord on your dump valve(s) and keep the valves open after the last bubble has exhausted...water will enter and continue to flood your BCD until you release the power inflator button/dump valve release cord...

Release the button on your power inflator/dump valve release cord immediately following the last bubble being exhausted...

If water is coming in through your check valve(s) without being activated...they need to be removed and cleaned...

Best...

Warren

 

[BlueTrin]

BT...

The water in your BCD is not coming in through the dump valve...this is a one way spring activated check valve...

When you exhaust air though your power inflator or by pulling the cord on your dump valve(s) and keep the valves open after the last bubble has exhausted...water will enter and continue to flood your BCD until you release the power inflator button/dump valve release cord...

Release the button on your power inflator/dump valve release cord immediately following the last bubble being exhausted...

If water is coming in through your check valve(s) without being activated...they need to be removed and cleaned...

Best...

Warren

So if I keep pulling on the rope on the dump valve of my BCD there is no chance water will get in eventually ?

Thanks for the explanation.

 

[JackD342]

So if I keep pulling on the rope on the dump valve of my BCD there is no chance water will get in eventually ?

Thanks for the explanation.

No, not exactly. When you open the dump valve by pulling the hose, you are "holding the door open." As long as air is coming out, little or no water enters. If you hold it open after air is done escaping, you will let some amount of water in. Same with the drysuit valve. If you only auto purge air by "pumping" your arm with some spring resistance, water entry is unlikely. If you purge manually by pressing the valve, you are far more likely to allow water in when no air is exiting.

 

[tursiops]

So if I keep pulling on the rope on the dump valve of my BCD there is no chance water will get in eventually ?

Actually, some folks have had a BCD failure by pulling on that "rope." The material around the dump valve gets weakened by the pulling, and ultimately gives way. Best to use the exhaust button on the LPI to get air out of the BCD. No stress on the area of the check-valve on the shoulder that way. And, not all BCDs have that cable inside the corrugated hose, so if you try and use it, nothing happens. But they all have the dump button on the LPI....

 

[seeker242]

Dry suit valve is much more complicated, compared to a BCD dump valve.

 

[BlueTrin]

No, not exactly. When you open the dump valve by pulling the hose, you are "holding the door open." As long as air is coming out, little or no water enters. If you hold it open after air is done escaping, you will let some amount of water in. Same with the drysuit valve. If you only auto purge air by "pumping" your arm with some spring resistance, water entry is unlikely. If you purge manually by pressing the valve, you are far more likely to allow water in when no air is exiting.

Yea I was almost sure that I could get water in my wing using only the bottom valve

Actually, some folks have had a BCD failure by pulling on that "rope." The material around the dump valve gets weakened by the pulling, and ultimately gives way. Best to use the exhaust button on the LPI to get air out of the BCD. No stress on the area of the check-valve on the shoulder that way. And, not all BCDs have that cable inside the corrugated hose, so if you try and use it, nothing happens. But they all have the dump button on the LPI....

I find it easier to dump using the bottom valve, I just have to raise a bit the bottom part.

My corrugated hose has to be pulled quite strongly if I want to get the last bit of air or I have to raise myself upwards.

I don’t have a shoulder dump valve.

I can see what you mean: I can see the valve break if it gets worn out.

 

[W W Meixner]

So if I keep pulling on the rope on the dump valve of my BCD there is no chance water will get in eventually ?

Thanks for the explanation.

BT...

Water will get in as long as the power inflator button/dump valve cord are held open after the last of the air has escaped...

Best...

Warren