Scubagaskets getting into the Reg business

[rsingler]

BTW, I took my SG-S2T2 set to Anilao for a heavy duty trial two weeks ago. Forty-seven dives over 13 days. About a third were in moderate to heavy current. About twenty involved deco, with dive depths around 80'.

Throughout it all, the reg set was a champ! All it got was a quick dunk in a freshwater tank and a hose in the mouthpiece at the end of each day.

There was no change in second stage tune over the trip, and I never had any sensation of air hunger in current. The Venturi augmentation when I was working hard made breathing effortless.

A check of my gear now that I'm back shows stable IP with good lockup, and the second is still cracking at 1.2". Maybe for fun, I'll tear it down again and see how it looks inside. All told, I'm pleased, and in 316SS, I'm expecting great longevity.

 

[Eric Sedletzky]

I’ve been using mine for silty low vis cold water beach diving, putting it through the rigors of our urchin dives. I crawl out of the water onto the beach on all fours so it’s getting whatever grime is in the surf and scud at the waterline. I soak it overnight in a tub hooked to the tank and pressurized. So far IP is perfect sitting at 135 with no wandering.
I don’t know how many dives - every Sunday generally two dives over a few months now.
The second stage runs really smooth.

 

[lowwall]

Do people actually think these regs will spontaneously combust and explode into flames if they are used for 100% O2?

Autoignition (your "spontaneously combust") requires much higher temperature than we will ever see breathing through a reg.

But stainless steel absolutely can burn when exposed to the flow of high pressure oxygen if there's an ignition source. This could be either from another substance in the reg that will autoignite such as oil or an impact from fast moving particles such as aluminum oxide from a tank.

I think the company's concern was regarding their initial plans for a reusable 316SS flat filter.
Sintered SS would probably not be a great choice for a high pressure, high flow, oxygen pathway.

Makes sense. A stainless steel sintered filter could actually cause a catastrophic fire as the relatively fluffy material is much easier to ignite than the solid metal of the walls of the stage. It's the same principle as a feather stick or wood shavings being easier to ignite than a log. Once ignited, the filter will produce a shower of ignition sources that may result in ignition downstream.

There's a lot of literature on this. For example see https://ntrs.nasa.gov/api/citations/20120015993/downloads/20120015993.pdf

Another is Combustion of Metals in Oxygen-Enriched Atmospheres which contains the following nugget:

Another case happened in the Marshall Space Flight Center in 1992 when the shims and pistons made from 316 stainless steel combusted in a 35 MPa [approx 5000psi] oxygen pressure atmospheres, which led to the explosion of the testbed.

 

[BoltSnap]

Another case happened in the Marshall Space Flight Center in 1992 when the shims and pistons made from 316 stainless steel combusted in a 35 MPa [approx 5000psi] oxygen pressure atmospheres, which led to the explosion of the testbed.

It is nice warm gas to breathe, what's the problem? Ice divers would be very happy

 

[Eric Sedletzky]

Here’s what happens when you switch to 100% at final deco:

 

[Umuntu]

Here’s what happens when you switch to 100% at final deco:

I would be interested to know how much sealife is killed with every one of those nuclear tests and over what radius … ?

I wonder if there’s been any research on that.

Fishermen are banned from using explosives for fishing.

 

[Eric Sedletzky]

I would be interested to know how much sealife is killed with every one of those nuclear tests and over what radius … ?

I wonder if there’s been any research on that.

Fishermen are banned from using explosives for fishing.

I’m sure it was horrific!

 

[Gone for diving]

Autoignition (your "spontaneously combust") requires much higher temperature than we will ever see breathing through a reg.

But stainless steel absolutely can burn when exposed to the flow of high pressure oxygen if there's an ignition source. This could be either from another substance in the reg that will autoignite such as oil or an impact from fast moving particles such as aluminum oxide from a tank.



Makes sense. A stainless steel sintered filter could actually cause a catastrophic fire as the relatively fluffy material is much easier to ignite than the solid metal of the walls of the stage. It's the same principle as a feather stick or wood shavings being easier to ignite than a log. Once ignited, the filter will produce a shower of ignition sources that may result in ignition downstream.

There's a lot of literature on this. For example see https://ntrs.nasa.gov/api/citations/20120015993/downloads/20120015993.pdf

Another is Combustion of Metals in Oxygen-Enriched Atmospheres which contains the following nugget:

Another case happened in the Marshall Space Flight Center in 1992 when the shims and pistons made from 316 stainless steel combusted in a 35 MPa [approx 5000psi] oxygen pressure atmospheres, which led to the explosion of the testbed.

From my understanding anything can burn it the right conditions with O2.

It's kinda like saying my ultimate 4x4 doesn't get stuck....
You just haven't got in a big enough hole....
PS... I know of a few holes.

 

[Eric Sedletzky]

I just think of all my years working in body shops with Oxy/ acetaline torches, grease and oil, filth, combustibles everywhere, dirt, grime, etc.
Never seen one fire or explosion turning valves on or changing out tanks. Those welding regs, fittings, or torches aren’t always the cleanest things either.

 

[happy-diver]

There is no issue with stainless steel

Unlike a head full of marbles the more you have the less banging around into each other doing more damage

Just love stainless, just thinned down some nuts to fit, and ground some dome nuts into domes today

Are they still doing nuclear tests