O ring visible between cylinder and valve.

[dahab boris]

I changed that as mentioned in the post above.


It is filled with the air now. I plan to send them for cleaning and pressure test. Most probably change them in the future or use them only for shallow air dives.

If they pass the required safety tests, on you go.
If they don't, or they aren't tested, good luck

 

[Agro]

Check if the threads of the valve are compatible with those of the bottle

For god's sake do so! Valve is M25x2, cylinder could be G3/4. This would explain, why you were not able to close the gap. A gap is NOT normal at all. Even a completely wrong o-ring never ever must be seen, there must be zero gap. You had 2 problems:
- Wrong o-ring
- Gap
Those 2 facts have nothing in common.

A M25x2 valve in a G3/4 zylinder will survive about 200 bar, sometimes a bit more, sometimes a bit less, then they explode. Several divers have been killed by this combiantion.

If your combination is correct (M25x2 to M25x2) then I can not explain the gap. Nevertheless it is wrong, O-ring will be extruded again.

 

[insomnia]

For god's sake do so! Valve is M25x2, cylinder could be G3/4. This would explain, why you were not able to close the gap. A gap is NOT normal at all. Even a completely wrong o-ring never ever must be seen, there must be zero gap. You had 2 problems:
- Wrong o-ring
- Gap
Those 2 facts have nothing in common.

A M25x2 valve in a G3/4 zylinder will survive about 200 bar, sometimes a bit more, sometimes a bit less, then they explode. Several divers have been killed by this combiantion.

If your combination is correct (M25x2 to M25x2) then I can not explain the gap. Nevertheless it is wrong, O-ring will be extruded again.

Please read below.

I have changed the o ring for 25x3,5mm and all is good. Seems I got bad spare o rings (24x3,8ish) from the seller.

 

[Sascha314]

Seem and believe are words I would not like to use in possible life threatening situations.

How can a smaller O Ring cause a gap AND be extruded at the same time? Could that.be reproduced and explained?

 

[insomnia]

Seem and believe are words I would not like to use in possible life threatening situations.

How can a smaller O Ring cause a gap AND be extruded at the same time? Could that.be reproduced and explained?

Diameter of 24x3.8mm is smaller but thickness is bigger (one was almost 3.9mm thick). Regular o ring should be 25x3.5mm. So I used those and all is fine. No gap, no extrusion, no leak.

 

[Garth]

I would also like to see the inside of the tank but if I was to take ownership of this tank I would do some cleaning and rust removal before putting back into service.

 

[insomnia]

I would also like to see the inside of the tank but if I was to take ownership of this tank I would do some cleaning and rust removal before putting back into service.

Yep, I mentioned that earlier.

I changed that as mentioned in the post above.


It is filled with the air now. I plan to send them for cleaning and pressure test. Most probably change them in the future or use them only for shallow air dives.

 

[Agro]

Please read below.

As I mentioned, you had 2 problems.
1) Wrong o-ring, this problem is solved.
2) Gap. Perhaps you solved it, perhaps you "solved" it by a wrong valve M25x2 in G3/4. Perhaps you have a tickinig time bomb. Please, please check this.

 

[Agro]

Diameter of 24x3.8mm is smaller but thickness is bigger (one was almost 3.9mm thick). Regular o ring should be 25x3.5mm. So I used those and all is fine. No gap, no extrusion, no leak.

PERHAPS all is fine, perhaps you have a timebomb.

Even a 4mm o-ring will not produce a gap, it will be squeezed more but you will be able to screw in the valve completely. Still gap my be the result of M25x2 in G3/4.

Where do you live? In a country where G3/4 tank threads are common?

 

[insomnia]

As I mentioned, you had 2 problems.
1) Wrong o-ring, this problem is solved.
2) Gap. Perhaps you solved it, perhaps you "solved" it by a wrong valve M25x2 in G3/4. Perhaps you have a tickinig time bomb. Please, please check this.

I have checked that before. Tank is M25 same as valve.