Question [Poll] Have you needed a manifold?

[justinthedeeps]

Being the "Technical Diving" thread, chances are most have dived/trained using a manifolded twinset configuration of double back-mounted cylinders.

A standard, convenient way to carry a lot of gas on our backs.
Commonly found throughout the world, foundation of nearly all open circuit 'tech' courses, including in remote locations.

A manifold is readily included, because of rarely occurring but possibly important advantages--most notably in long overhead environments (caves).

I am curious how many of us have actually used that manifold? So here is a poll.

Please share stories!

 

[ScubaFoxx]

Never needed to close anything, might be luck. Might be good maintenance.
I'll do valve drills once a while but not as often as I used to. If something were to happen all is good, also knowing after something springs a leak it's not going to be all at once..

Had someone in the water today that said his DIN oring was leaking. I inspected it and It looked all good. He insisted that he saw cracks in it and wanted it replaced. I replaced it with one that I had and he went his way.
After he did his second dive he put his set on the table and his buddy said he leaked again.
I heard their conversation and there was an audible leak and saw some water bubbling.
It was between the 1st stage and the din insert.
Weird for a leak, almost new set (6mo) but told him to have it serviced or returned as I wasn't going to just touch someone's first stage. It did show me today that such failures do exist, I just haven't had them myself. I'm not including swivel leaks

 

[Rilelen]

I’ve had leaky first stages and leaks with the DIN connection; some of this is probably a numbers game - if you do enough dives, interesting low probability events pop up.

 

[DiveLikeAMuppet]

You missed one option: closed the manifold by accident by not resetting properly after a series of valve drills, found out some time later after being impressed by my impeccable gas consumption.

 

[justinthedeeps]

Right so some of these smaller, minor leaks are hard to detect until submerged. Otherwise, someone might have heard the leak, or noticed it when you opened your valves and saw a lower pressure on SPG than you expected or need for the dive.

Some credit to having valve options for minor leaks... Are we talking "small bubbles, no troubles," or "this dive cannot be completed as planned without closing a valve?"

When and how did these bubbles begin? Were they present during initial bubble checks, right after entering the water? Or escaped being noticed at this point? Or did they begin to happen later in the dive?

If you see bubbles on your initial checks, do you opt to close a valve? Or are the bubbles small enough that you should actually leave the valve open--safer? If the bubbles are big enough on initial checks that you need to close a valve--should you even do that dive at all? Did you dive anyway?

 

[happy-diver]

Tighten your din with only your fingers, so the oring seals, nice
but do not tighten to metal to metal, damaging valve and reg

Do not, use the reg as lever, for that extra little bit of tightness

Do not adjust your reg angle after tightening, you'll mess it up

When pressure is released, and then some more, press the reg
towards the valve to compress the oring then unscrew the reg

When pressing and loosening, you can use your reg, as a lever
but only, if the din wheel begins to move at the same instance

Do not, do everything backwads, so as to loosen reg, from din

Fillers, overtighten too, so when valve gets to where it's going

Reseat your valves



I do not know, is there any thing else I don't use any din cap
and go heaps and heaps of dives, and I'm pretty rough with
my stuff but rarely change any orings and theyre always dry

and I don't cap regs so the moisture can get out not stay in


and have never done a valve drill but reach back there sometimes and wonder

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[MaxBottomtime]

I always left my valves open. The tank filler at the shop closed my manifold for some strange reason, and I failed to check it before a dive. At 180 feet I noticed I was going through my gas faster than usual. I had to open the valve to get gas from both tanks. Fortunately, I had the same gas in each tank.

 

[justinthedeeps]

Is anyone here talking about a "going to lose most of the gas" kind of leak?

Did you close a valve for a "losing all my gas" kind of leak, or a "I'm going to stop these minor bubbles" leak? [The latter case would be questionable from a safety/operational standpoint]

Minor leaks, while a good maintenance item, are basically ignorable from a valve-operation standpoint. No closing of valves--same as with single cylinders. You'll see it constantly in busy places, just service it after the dive (or not....)

 

[smitr]

Never had to use the isolator. I've been on dives with buddies who have due to a first-stage leak, so it happens.

 

[Fat old english bloke]

Couldn’t see it as an option, but I needed one for Fundies….