Bc without an air release valve on the shoulder.

[RonFrank]

I have seen BC's with two, three and four dumps. How often do these things fail? In my experience never! Most BC's wings have one on the left shoulder and a second on the right rear. Sounds like a major failure waiting to happen!

 

[bergersau]

Picture would help. I am not familiar with all Sherwood BCs but many BCs have the pull cable inside the inflator hose. Steel cable (short enough you don't bust the inflator hose) connected at both ends. If the inflator hose attaches to the BC at a round looking thing with vent holes this might be what you have.

Since the O.P was talking about a right shoulder OPV/dump and the inflator hose is normally routed over the left shoulder I suspect you are talking at cross purposes.

However I am no longer a fan of the inflator hose pull dump. I've just replaced an old wing with a failed inflator hose mounting collar on the left shoulder. Now I need to admit that it was NOT tugging on the pull dump that caused the fitting to fail. Rather it was a cheap wing and the plastic thread stripped. I was on the surface and adding air to the wing in order to talk to my 8year old son who was swimming on the surface.

Regardless, having the entire corrugated inflator hose pop off the wing and dump all the air in my wing was very disconcerting. Luckily I was doing some skills revision in a pool and the only harm was to my dignity when I had to swim the rig up off the bottom. I was about 4lb over weighted to begin with as I hadn't bothered to adjust my weight belt for a fresh water pool instead of the ocean and still had a near full tank, so I sank like a stone.

When I ordered my new wing I specified a simple elbow instead of a Dump valve fitting for the corrugated hose mount. I don't want to experience that failure again in open water - That could be a real problem. Pulling on that corrugated hose - just doesn't seem smart to me after experiencing that failure.

On the bright side, my wife saw the failure and had no objection to me spending money to replace the old cheapo wing with a new Dive Rite Voyager exp wing. Looks good - now I just need to get away to dive the thing.

 

[Zung]

The right shoulder dump valve is the only device I use to dump air. My wife often uses the butts dump when she's not vertical, but I haven't mastered that technique yet.

Usually divers are taught to use the inflator to dump air, but I find it slow and cumbersome.

 

[TSandM]

I've had a friend lose the cap on a dump valve (didn't check before diving, to make sure it was fully screwed in). There was also a recall a couple of years ago of dump valves because the steel the spring was made off was rusting, and the springs were at risk of breaking. (I'm not sure whether any actually broke.) So they ARE potential sources of failure, but I'm not going to say that having extra dump valves means "you are going to die!" I did want to reassure the OP that there are a lot of divers using systems that have only two methods of venting gas, and we don't seem to run into a great many difficulties.

 

[halocline]

I have seen BC's with two, three and four dumps. How often do these things fail? In my experience never! Most BC's wings have one on the left shoulder and a second on the right rear. Sounds like a major failure waiting to happen!

Usually the hip dump on wings is on the left rear, not right, although I have seen a few older dive rite travel wings with the dump on the right. It's on the left because (I assume) tech divers can then use their left hand only for inflating/deflating, with the right hand saved for other tasks, like pointing a light.

I have seen, twice, a new diver yanking on the pull dump for the inflator hose hard enough to pull it right off, causing immediate flooding of the BC. Both times this was with rental gear. It's not a pretty picture, especially when you have overweighted newbie divers....

I've also seen quite a few small leaks at OPVs on BCs; nothing that would be immediately dangerous, but annoying.

 

[socaljohn]

Since the O.P was talking about a right shoulder OPV/dump and the inflator hose is normally routed over the left shoulder I suspect you are talking at cross purposes..

You are quite right.. I need to work on the pesky reading thing.
Sorry for the misdirection.