Is this normal for scuba tanks?
- Thread starter Noah Norman
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2airishuman
Contributor
The scorkel and its generic variants have been the subject of much discussion and derision here. If it works for you, most of that isn't relevant.
There are two questions you should consider related to the safety of the cylinder. The first is the one you ask. There should be no visible corrosion or residue of any kind on the inside walls of the cylinder. Depending on what is there, you may be able to remove it using hot (boiling) water mixed with dish soap or household ammonia, followed by several rinses. Marbles or other objects can be used combined with rolling the cylinder. There are also commercially available bottom brushes and whips that can be used to perform mechanical cleaning.
Second, as implied upthread, there are safety standards for the manufacture and testing of high pressure cylinders as defects or damage can lead to explosion and personal injury or death. While the risk is lessened somewhat with a smaller cylinder, it is still significant. For cylinders used in the USA there should be a "DOT-3AL" stamp followed by the pressure rating in PSI, or a "UN" stamp with internationally recognized information. These would indicate that the manufacturer claims the cylinder follows the applicable safety standards, though there have been instances of fradulently placed markings on small imported tanks (notably for portable welding equipment).
The absence of such markings would indicate that the cylinder does not meet USA standards, and may be unsafe.
There are two questions you should consider related to the safety of the cylinder. The first is the one you ask. There should be no visible corrosion or residue of any kind on the inside walls of the cylinder. Depending on what is there, you may be able to remove it using hot (boiling) water mixed with dish soap or household ammonia, followed by several rinses. Marbles or other objects can be used combined with rolling the cylinder. There are also commercially available bottom brushes and whips that can be used to perform mechanical cleaning.
Second, as implied upthread, there are safety standards for the manufacture and testing of high pressure cylinders as defects or damage can lead to explosion and personal injury or death. While the risk is lessened somewhat with a smaller cylinder, it is still significant. For cylinders used in the USA there should be a "DOT-3AL" stamp followed by the pressure rating in PSI, or a "UN" stamp with internationally recognized information. These would indicate that the manufacturer claims the cylinder follows the applicable safety standards, though there have been instances of fradulently placed markings on small imported tanks (notably for portable welding equipment).
The absence of such markings would indicate that the cylinder does not meet USA standards, and may be unsafe.
OP
Noah Norman
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OP
Noah Norman
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2airishuman
Contributor
::shrug:: UN Cylinder made in China, assuming that's the UN mark not a pi symbol. See the UN/ISO section here for what it's supposed to look like. From a regulatory standpoint I don't think it can be filled or hydro tested in compliance with USA regulations because it does not have a USA approval.
You can throw it away in 2026, since nobody in the US will recertify it.
And forget going to a dive shop for a fill.
OP
Noah Norman
Registered
No, it is literally a pi symbol.
OP
Noah Norman
Registered
You wasted your money.
Then is is possibly a fake set of markings, since it is not UN markings.
They are not allowed to put any gas into it. They can look inside it, that's it.
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