Old S bottle of helium

[Endler's]

Helium is the second smallest atom. It eventually escapes the pores in a rubber balloon. (Mylar has less space between its molecules, so the balloon stays inflated longer.)

I suspect it can escape valve seats over time.

Good Luck lostsheep! 'Wonder if you could take tank to local gas supply, and have them test it; also maybe weigh tank, and give you estimate how much gas in cylinder.

One final thought. Have you cracked it open, to check for gas? Remember to check for wasps!

 

[Alaskan Scuba Dude]

What grade of Helium?

 

[lostsheep]

What grade of Helium?

Clearly, fascinatingly , yet curiously 42. Are you interested now?

 

[GF99/99]

Helium IS the second smallest atom. It eventually escapes the pores in a rubber balloon. (Mylar has less space between its molecules, so the balloon stays inflated longer.)

I suspect it can escape valve seats over time.

Good Luck lostsheep! 'Wonder if you could take tank to local gas supply, and have them test it; also maybe weigh tank, and give you estimate how much gas in cylinder.

One final thought. Have you cracked it open, to check for gas? Remember to check for wasps!View attachment 723452

I use DST first stages for bailout regs and I find that about every year (continuous use) my deep bailouts with high (over 70%) He mixes the little clear rubber environmental seal is always bubbled out a little. My theory is the He slowly makes it way past the diaphragm and gets trapped between the diaphragm and environmental seal, when you unscrew it you can hear a little gas escape.

This only happens on my deep bailout regs.

 

[kensuf]

It's a ticking time bomb. I'll be happy to take it off your hands and properly dispose of it for you.