burping loop

[lermontov]

I know were trained to release pressure on the loop in a BO scenario as we ascend but opening and closing the loop has a the risk of getting water in and eliminating the option of getting back on.

If we have a reached max loop volume the over pressure relief activates and as long as we can compensate by releasing our BCD/dry suit well maintain buoyancy -even on an ascent the pressure valve will continue to release with ambient pressure changes -seems obvious; what am I missing?

i guess if your light on weight it could get tricker as you go up especially if your breathing down your BO gas

 

[Dsix36]

1 - burping the loop is not difficult and should be thoroughly trained in your mod 1. The ingress of water is so minimal that it is a non concern.

2 - controlling your buoyancy is much easier when you also control the loop volume vs. letting it just pop off when ever it wants to.

3 - without burping the loop you are taking a chance of an opv failure (or stick) that could potentially blow something else out and result in a sudden full flood.

 

[DiveTucson]

I will echo this. Loop volume is the first thing we should be maintaining for buoyancy control if we are on the loop or bailed out. Most teach loop, suit, BC in order of importance.

Quickly opening and closing the loop allows almost no water intrusion.

 

[lermontov]

yep im all ok with the points raised -i didnt clarify - just a bit of back ground info- discussion came up after a buddy got himself into a stress situation after multiple issues and had to BO and in the middle of all this he got task loaded and didnt close his valve properly and flooded his unit -so really its prioritise if the loop can look after itself for a few minutes while you address other more urgent issues and if needs be leave it to its own devices

 

[rjack321]

Many units don't require opening the DSV to vent the loop. The OPV will easily handle it. Meg and Kiss are two I have personally. You can also easily vent via a BOV

But if the loop is compromised to the point of bailing, why would you worry about going back on it?

 

[lermontov]

Many units don't require opening the DSV to vent the loop. The OPV will easily handle it. Meg and Kiss are two I have personally. You can also easily vent via a BOV

But if the loop is compromised to the point of bailing, why would you worry about going back on it?

yes good point - i guess the discussion was around should he have put the loop issue aside and focussed on other issues instead. Then progressed to do we need to worry anyway

 

[rddvet]

I can see how having a cascade of issues can lead to enough stress to fail to burp the loop, but we did it over and over and over in our training until it wasn't a second thought. Obviously even then it can go to hell in a handbasket. But not venting the loop will eventually lead to bigger issues when you can't control your ascent quickly enough. Holding the mouthpiece down and burping will barely let any water in. Even holding it in it's normal in-mouth position and burping won't let much in

 

[Degenerate]

If your counterlungs are completely full and you take a breath of your bailout reg your buoyancy will get very positive unless your weighting is way off.
You do not want an excessive amount of gas in your CCR when you've bailed, you're gonna have a bad time.

 

[stuartv]

I know were trained to release pressure on the loop in a BO scenario as we ascend but opening and closing the loop has a the risk of getting water in and eliminating the option of getting back on.

If we have a reached max loop volume the over pressure relief activates and as long as we can compensate by releasing our BCD/dry suit well maintain buoyancy -even on an ascent the pressure valve will continue to release with ambient pressure changes -seems obvious; what am I missing?

i guess if your light on weight it could get tricker as you go up especially if your breathing down your BO gas

Per my training, there is a pretty simple reason for not doing this: If you can hold a 10' stop with full counter lungs (as you'd have if doing what you described), then you are somewhere between over weighted and VERY over weighted (depending on the actual CL volume in your specific unit).

If you get your weighting spot-on, you will not be able to hold a stop on BO, with full CLs.

 

[Dr. Doug Ebersole]

I agree that you should vent your counterlungs as you ascend on bailout and (1) not be so overweighted that you could hold a shallow deco stop with them fully inflated and/or (2) rely on the OPV to vent them adequately.

The "trick" to venting your counterlungs with a DSV is to make sure you point the mouthpiece down, and not up, as this will allow the gas to escape without flooding your loop.