BC keeps filling up with water

[Deefstes]

I'm not sure I know how the mechanism of an air dump valve actually works. The reason I'm asking this is because my wife's BC is forever filled with water after a dive. We have very similar BCs. I have the TUSA Platina Evolution and she has the TUSA Selene. Apart from the bladder and the fit being slightly different, the BC's are virtually identical. They certainly have the same hardware in terms of inflators and dump valves.

I hardly ever find water in my BC but, like I said, my wife has to dump water from her BC after just about every dive. I'm starting to wonder if it could be related to how she dumps air. Could it be that she holds the purge button down too long after the air had been purged already? Is there supposed to be some sort of a non-returning valve that will allow air escaping but stop water rushing in or is it merely the escaping air that stops water rushing in?

I'm suspecting the dump valve(s) because I can't see any bubbles escaping from the BC during her dives which would suggest to me that the BC is leaking elsewhere.

Does anyone have knowledge or experience of this issue?

Thanks

 

[Dirty-Dog]

If the valve is open, and there's no air coming out, then water will come in.
I suspect that you probably always have a least a little air in your BC, and she's completely draining hers. Then if she feels a little floaty and pulls the dump valve, water will enter.
It won't hurt anything.

 

[00wabbit]

Just make sure to drain and rinse the inside.

 

[Karibelle]

You might also check the connections on the BCD, just to make sure they're all closed. Then as has been stated, if the valve is open and no air is coming out, water is going in. Perhaps suggest that when she goes to vent, she gets in whatever position she wants to do that (head up, arm up perhaps) and wait a couple of seconds before depressing the valve...

 

[fire_diver]

It's normal to get some water in a BC during diving. If you try to dump after it is empty, or your position has the bubble somewhere else then water will enter.

The better you are weighted, the less you will be adjusting the air in your BC.

 

[pasley]

...my wife has to dump water from her BC after just about every dive. I'm starting to wonder if it could be related to how she dumps air. Could it be that she holds the purge button down too long after the air had been purged already?

Unless there are air bubbles comming out of a pressurized BCD immersed in water it is your wife continuing to dump air after the BCD is empty.

Here are some observtions, just guesses but if they are on the mark they will point to the problem.
1. Your wife decends quickly. The decent should be slow and controlled. You should be able to stop at any point eaisly. You should be able to stop 6 feet off the bottom.
2. You wife is still doing the yo-yo, add air, too much, dump air, add air, dump air.
3. Your wife continutes to dump air after her head is under water. This sets up the yoyo. If your head is underwater, you are sinking and are negative. Your BCD should be empty (if not you are overweighted). Air dumped after your head is underwater on the decent is air you will have to add back to get to neutral.
4. You are not adding air to your BCD soon enough. You should start adding air in very small puffs at about 10 feet and every 5 to 8 feet after that. This will keep your decent speed down.
5. Excessive speed maket it hard to control buoyancy. When you add air, you have to wait for the air you added to overcome momentum of the downward decent. If you are going fast, by the time this happens, you have to add more air, then when you finaly stop decending you have too much air in the BCD and start floating up.
6. Once on the bottom look at your swimming position. Are you really horizontal 0-----< or are you \ with your head up. If so you will keep trying to dump air from an empty BCD as you "float up" when in fact you are swimming up at an angle. Then you stop swimming to dump air and you sink, thinking you have dumped the air you continue only to have the same problem again.
7. Wife is dumping air from the inflator hose held at ear level. This forms a J loop in the hose and traps air in the BCD. Remember you training, fully extend the hose.
8. Dump air from where the air is. If you are butt high, dumping air from the hose or a shoulder dump will do nothing as the air bubble will always be at the point closest to the surface.

So to recap, if she stopps dumping air from an empty BCD, keeps her position horizontal in the water and dumps air from where the air is in the BCD she should have almost no water in the BCD.

 

[PacificDiverNw]

On the instruction book of my bc it says sometime water will get in through the inflator hose when dumping air, but to make no water get in you can use one of the other dump valves where you just pull the string.

 

[Deefstes]

Thanks for all the responses. So it seems that pressing the purge button on the inflator hose when the BC is empty will cause water to flow in? That makes sense and I'm pretty sure that explains the constant filling up of my wife's BC.

We both try to weight ourselves such that we require no air in the BC during the dive. We might add some air at depth just to fine tune our buoyancy on the reef but we typically dump everything as we start making our ascent. I suspect this is where she basically just hold the button down too long in her effort to make sure that all the air is purged.

I'll mention to her to try use the kidney dump valve next time to see if that makes a difference.

Thanks again.

 

[bluejaykaren]

It is VERY unlikely but a friend of mine went to sell her bcd, I don't know what brand it was, she pulled it up on the web to get the specs for her add and found it had been recalled because they would fill up with water because of a malfuntion. I think she said it had to do with a spring. I would check to be safe.
I had the same problem as your wifee did when I switched from a bcd that had a much larger wing. I was getting all the air out much faster than I had before so my first dive with it got a lot of water in it.

 

[mrfixitchapman]

Read this thread from a a while ago. I use the 'air siphon' technique and I do not have more than a tiny bit of water in my wing after a dive.

http://www.scubaboard.com/forums/ad.../403733-air-siphon-technique.html#post6135927

DC