Question CNG HP Storage cylinders as cascade option.

[Ty Hamby]

Asking for a friend. He see's CNG cylinders (Tanks) show up at government auctions from time to time. They are mostly 3600psi and big. City bus tank big. It would seem they expire after some time. Possibly disposable. His question is, has anyone thought about using a [Type 1, 2, or 3] CNG tank for HP breathing air storage. They sometimes sell in the under $50 buck range. Thoughts? I'll pass on any wise advice.

 

[Wookie]

He wants them for his own use, no neighbors within explosion distance?

 

[Ty Hamby]

3600psi vessel is a 3600psi vessel. Whether the gas is flamable or inert. He is just wondering of any other concerns with using a CNG vessel for breathing air. No people only chicken and cows could be harmed.

 

[iain/hsm]

He see's CNG cylinders (Tanks)

Tanks? Tanks?

Tanks are what the army drive.

 

[Ty Hamby]

Tanks? Tanks?

Tanks are what the army drive.

Aye, aye Sir. I was absent that day Sir. I will do better Sir. Cylinders Sir! Yes, Sir!

 

[iain/hsm]

3600psi vessel is a 3600psi vessel. Whether the gas is flamable or inert. No people only chicken and cows could be harmed.

My concern is purely for those cows and chickens.

Now we are talking in the light of re purposing CNG Compressed natural gas cylinders for storing breathing air.

I was a commercial diver and on one of my jobs the West Sole offshore pipeline an 16 inch 1800 psi gas pipeline in the southern sector of the North Sea to the gas terminal at Easington near Hull UK England. During inspection and anode placement we found a WW2 German airborne Mine resting against the pipe enjoying the cathodic protection offered. Once reported the terminal manager had to give up his weekend at the golf course and told us if we were wrong and had found an old boiler then we would never work offshore again. The pipeline gas supply was shut and the pipe flooded with salt water while a MkIV delayed mine lifting bag was attached and to our amazement it lifted without any harm to the Sally Sealink ferry who decided to sail by waving back at us in an inflatable gemini standing guard over our prize. It was then drifted between the West Sole pipe and the Leman Field and then placed back on the sea bed with a 7 lbs placement of HE together with the 500 lbs already on the Luftwaffe A. Now a lot of fish were killed that day but it could have been worse imagine if it had been cows and chickens.

Natural Gas or North Sea gas is by and large methane and has a smell akin to the biblical fire and brimstone, the sulphur smell of Hell.

British Gas decided not to remind the population of the popular next destination and to change the natural odour from fire and brimstone by introducing a chemical known as Mercaptan to change the fire and brimstone smell into the smell an old dog makes when you feed it to much tinned dog food and let it lay by the fire without letting it out.

Now Mercaptan is your problem when repurposing old CNG Cylinders for breathing purposes.
I will detail later Iain.

 

[iain/hsm]

Conversely you lot in 1937 built a new school housing some 500 pupils and teachers in New London Texas for the community residents in the East Texas Oilfield when on March 18th at 3.05 pm a teacher Lemmie R Butler switched on a machine in an area filled with a natural gas and critically a 16:1 ratio of air atmosphere and ignited a 253 foot long by 56 foot wide culvert beneath the school building that resulted in the death of 298 pupils and staff out of 500. The walls collapsed the roof fell in and the explosion was heard 4 miles away. A two ton slab of concrete crushed a car 200 foot away. Twenty five embalmers were used in the clean up.

Subsequent the American Government required a smell to be added the Methane gas. And again the same problem occurs in trying to re purpose these cylinders as you can't get rid of the smell. Iain

 

[iain/hsm]

Aye, aye Sir. I was absent that day Sir. I will do better Sir. Cylinders Sir! Yes, Sir!

I think you will find its Aye Aye Captain only in the Royal Navy
And it's Yes Sir in the army LOL

 

[Tracy]

You won't get the mercaptan out of them. That is the reason you can't use a CNG tank for another application later. the Mercaptan impregnates the steel and you will get rotten egg smell forevermore.
Tried it. Cleaned it, tried it again, and again. They stink.

 

[Tracy]

You won't get the mercaptan out of them. That is the reason you can't use a CNG tank for another application later. the Mercaptan impregnates the steel and you will get rotten egg smell forevermore.
Tried it. Cleaned it, tried it again, and again. They stink.

Damn, I was too late. Iain beat me to it.