Question for those who plug their burst disks

[JHumbert15]

Hi All,

I have some LP steels that I'm looking to plug the disk on.

Firstly, I'm sure this is going to start some type of debate. I've read all other threads and made my decision, so, respectfully, please do not come tell me I shouldn't do it. I’ve tried to find the answer to my question and haven’t been able to, and I’m just looking for an honest answer to my questions, not to start a debate. My reasoning: I believe that, outside of a fire situation, removing/double disking/using a penny or dime/using a SS plug (whatever really) poses nearly no safety issue when overfilling a cylinder. I understand there's a chance the cylinder goes, but a properly VIP'd, Hydro'd, and cared for cylinder should pose no issue in my opinion. There are no cases that I know of or have read about (or seen provided from those who think this is the most dangerous thing in the world), where a steel cylinder has exploded from overfills. I also believe that cylinders are built with quite a bit of safety margin even when the proper disk is used. I'm not gonna go crazy, but I'd like 4-4500 in my LP85s without worrying about the disk going early, which has happened to me in the past with higher rated disks. They get weaker over time and I don't want that. I won't be doing this on my aluminums, or my old LP72s, just my modern Faber LP steels, and potentially PST 104s when/if I find a set. Even if I don't overfill them (I don't overfill every time I fill them), I don't want them to go early.

It seems NESS is the place to get the SS plugs, but it looks like it's a 3 piece assembly.

So, my questions.

I'm assuming I need the following, and build it like a normal 3 piece assembly-

Burst Disc Plug - Stainless Steel

john@northeastscubasupply.com

northeastscubasupply.com

S/S Blanking Plug for Burst Discs

john@northeastscubasupply.com

northeastscubasupply.com

Burst Disc Washer

john@northeastscubasupply.com

northeastscubasupply.com

1) Is this correct?
2) I just build it normally? (valve-washer-plug-assembly "bolt") I've only used DGX's 1 piece units before
3) The most important imo, what is the torque spec? Still 10 ft lbs?

Any other way you all recommend doing this? Does anyone just use a 3/8"-24 bolt? If so, what size? How do you install? (torque or just screw it in tight?)

Thanks for any help anyone can provide.

 

[happy-diver]

A bolt, and what do you think the filling people and the boat people will think

Has anyone just filled the plugs with solder

It is interesting that all the research does not bring all that one requires

 

[jale]

Hi
Does that burst-disk "thing" exist only in the US?
@happy-diver , is it also an Aussie "thing"?

 

[Angelo Farina]

Here in Europe burst disks are FORBIDDEN, as TRULY DANGEROUS.
I think it is the same all around the world. Get rid of them ASAP, this is my suggestion...
Or, even better, use DIN European valves, which are way safer and better built.

 

[jborg]

 

[JHumbert15]

Here in Europe burst disks are FORBIDDEN, as TRULY DANGEROUS.

This is my thought process as well. I think they kinda do more harm than good.

Yeah, I should’ve added this to my original post too lol. I just wanted an honest answer to my question because I haven’t been able to find it, but I know there’s no way my post isn’t going to start something.

 

[sea_ledford]

Here in Europe burst disks are FORBIDDEN, as TRULY DANGEROUS.
I think it is the same all around the world. Get rid of them ASAP, this is my suggestion...
Or, even better, use DIN European valves, which are way safer and better built.

Serious question, what makes them dangerous?

European DIN valves are different than US DIN? All I use is DIN and they all have burst disks. Are the threads compatible?

 

[Sevenrider860]

Dive Gear Express has some background on the use of burst disks on scuba cylinders in the US.

Pressure Release Devices aka Burst Disk | Dive Gear Express®

In the U.S. at the turn of the twentieth century, a series of boiler explosions caused significant loss of life. The most famous of the accidents, ...

www.divegearexpress.com

 

[nadwidny]

There are no cases that I know of or have read about (or seen provided from those who think this is the most dangerous thing in the world), where a steel cylinder has exploded from overfills.

August 1994. Waterton National Park in southern Alberta. Shop owner from Calgary died from plugged steels that were hooked up to a compressor, got over filled, and exploded.

There are a few more here on SB.

 

[JHumbert15]

August 1994. Waterton National Park in southern Alberta. Shop owner from Calgary died from plugged steels that were hooked up to a compressor, got over filled, and exploded.

There are a few more here on SB.

Fair enough. Any more info on this? How do you know it was plugged? I found a post you made about this in another thread and did a quick google search but couldn’t come up with much.

I would still bet there was an underlying cause. Out of VIP or hydro, or an old un-taken care of tank. That’s my speculation, because if it was reported to have exploded at 5000 PSI, that’s around test pressure for HPs, and 1000 ish over for LPs. I would not expect an explosion there. Without any more info I guess all we can do is speculate.