UTD's New Sidemount Configuration

[berndo]

Eventually did the shutdown after trying to stem the flow and saved some gas, but blew off 150 bar/2200 psi from the LH cylinder.

Wow, you should really get some training, especially before diving solo. Losing 150 bars is really bad. You can't 'stem' the flow under water when the reg is free flowing... kinda basic knowlege.

 

[Wibble]

Wow, you should really get some training, especially before diving solo. Losing 150 bars is really bad. You can't 'stem' the flow under water when the reg is free flowing... kinda basic knowlege.

Were you there? Do you know how large the cylinders were?

In any case, what's the rush. It's sidemount, so a fully-redundant system.

Was good learning though. Amazing how much it knocks your head around when it's blowing that hard. The attempt to stop it by shoving a finger in the reg didn't work, neither did sticking it in my mouth to see if that would stem the flow. So shut it down. Waited a bit. Then turned it back on for it to freeflow again.


As you're into giving advice @berndo; what do you think caused the freeflow? Was 7 degrees in fresh water, 10m max. The first stages are Mk25s and the second stages are XTX50s, both recently serviced (month before). Freeflow happened 5 to 10 mins in. Was slightly descending from 6m to 8m, breathing from the other reg (longhose), the freeflow being the necklaced one.

I checked the IP and it's pretty rock solid at 9.3 bar, doesn't creep and quickly returns to 9.3 when purging.

First or second stage?

 

[berndo]

Amazing how much it knocks your head around when it's blowing that hard. The attempt to stop it by shoving a finger in the reg didn't work, neither did sticking it in my mouth to see if that would stem the flow.

Yeah, that's why I said you should get some training. Sticking a finder into the reg doesn't stop a free flow. How can you not know this? A free flowing regs needs to be shut down.

150 bars is alot, even with small tanks.

 

[TheCatFish]

Sidemount: two completely separate and redundant systems.

UTD sidemount: a single system removing redundancy and adding considerable complexity.



A few weeks ago I jumped into a lake to test my shiny new drysuit. Have to dive sidemount as them's the rules of the lake (no solo CCR). Whilst diving, the backup reg with absolutely no forewarning or 'tickling' suddenly and violently freeflowed.

It's sidemount; there's the completely redundant other side which I was breathing from. Eventually did the shutdown after trying to stem the flow and saved some gas, but blew off 150 bar/2200 psi from the LH cylinder.

That UTD system would drain both cylinders unless you immediately and unthinkingly shut down the manifold. Not to mention having to bugger about turning knobs behind your head.

Wow, quite an unnerving event. Glad that you were able to resolve the incident without too much fuss. Simplicity and redundancy are worth their weight in gold!

 

[ginti]

@Wibble did you LOSE 150bar, or have you CLOSED A TANK with 150bar inside? Just curious here, I don't mean to judge anyone

 

[TheCatFish]

Were you there? Do you know how large the cylinders were?

In any case, what's the rush. It's sidemount, so a fully-redundant system.

Was good learning though. Amazing how much it knocks your head around when it's blowing that hard. The attempt to stop it by shoving a finger in the reg didn't work, neither did sticking it in my mouth to see if that would stem the flow. So shut it down. Waited a bit. Then turned it back on for it to freeflow again.


As you're into giving advice @berndo; what do you think caused the freeflow? Was 7 degrees in fresh water, 10m max. The first stages are Mk25s and the second stages are XTX50s, both recently serviced (month before). Freeflow happened 5 to 10 mins in. Was slightly descending from 6m to 8m, breathing from the other reg (longhose), the freeflow being the necklaced one.

I checked the IP and it's pretty rock solid at 9.3 bar, doesn't creep and quickly returns to 9.3 when purging.

First or second stage?

I'm not interested in ribbing you for losing 150bar beyond "close off that tank faster next time" (better to feather the handwheel below a malfunctioning regulator than fiddle with the reg while it is rapidly depleting).

Possible failure reasons: second stage diaphragm is broken? (bring to LDS) Maybe the first stage froze? (unlikely but if it froze, then it should be working fine now) Unbalanced first stage? (LDS again).

Post an update later if you can! Would love to know the answer myself.

 

[berndo]

Wow, quite an unnerving event. Glad that you were able to resolve the incident without too much fuss.

Freeflow should be expected, should not be unnerving at all (when you had some training) and is a run-of-the-mill issue. Sugar coating doesn't help anyone.
If had several free flows and never lost anywhere near to that much gas.

Wibble might be a joke account... most of the stuff he posts is hair raising. He can't be for real.

 

[TheCatFish]

Freeflow should be expected, should not be unnerving at all (when you had some training) and is a run-of-the-mill issue. Sugar coating doesn't help anyone.
If had several free flows and never lost anywhere near to that much gas.

Wibble might be a joke account... most of the stuff he posts is hair raising. He can't be for real.

Could be? I've seen Wibble around, plus he's got over 4k posts, I assume he can't be too big of a joker... but maybe I've got too much faith in the internet

As I'd mentioned above, I'm just not that interested in finger waggling at an internet stranger who lives an entire ocean away.

Not denying that losing 150bar is a ton of gas lost. It means that someone was fiddling with a flowing low-pressure orifice for a good 5-6mins before shutting the valve. Just glad I'm not reading about Wibble running himself empty like that guy from Bozeman.

 

[The Chairman]

Sticking a finder into the reg doesn't stop a free flow.

It certainly can. Anything to disrupt a runaway venturi effect can calm a reg down in a hurry. I've seen a bad first stage empty that much gas before and I've had a "bit" of training.

Let's not delve into commentary about what training someone might or might not have gotten.

 

[Wibble]

@Wibble did you LOSE 150bar, or have you CLOSED A TANK with 150bar inside? Just curious here, I don't mean to judge anyone

It was probably about 70 to 100 bar TBH. Ended the dive with 50 bar one side, 100 the other. Started with under 200 bar. Small cylinders.