Bubbling from neck of tank valve

[sealark]

It looks to me that the valve does not have enough OD to seal across the O-ring top. You can almost see the rubber in the picture. I would make sure you have the correct valve for that tank first.

 

[guruboy]

Pretty sure the valve is fine, unless AL6 and AL19 tanks require different valves and I never noticed before now

 

[guruboy]

Took the valve off. Not sure what to think.

Besides the stuff bubbling out, there was not enough residue anywhere else to stain a shop cloth to make it appear "wet" and nothing felt particularly greasy.

The oring is a little softer than the 90D ones I use but nothing came out when I squeezed it in the shop cloth.

 

[sealark]

Maybe something dripped on it and the O-ring is old and allowed some air to seep out through it. Hell replace the O-ring fill the tank and put about 6 inches of water in a 5 gallon bucket. Invert the tank and submerge the valve end in the water and watch it for any leaking. Bet it wont leak, let us know

 

[Jack Hammer]

I recently pulled a 6cf from use due to bubbling at the neck. When I went to inspect it the valve was frozen on. After forcibly removing (and destroying) the valve I found water in the cylinder. My buddy had been using it for suit inflation but I had been filling it. Not sure where water came from. After tumbling and cleaning it, it looks awesome inside, I used an Inspection Plus to better check the threads and found a few questionable spots. Cylinders aren't that expensive so it's scrap now. Not worth the risk to me. (I also did a new vis on all my tanks (a lot of tanks), they were fine).

Pay close attention to the thresds and where the O ring sets, if its fine change the O ring and if it doesn't leak recheck the cylinder periodically and do a vis on your other cylinders to be safe.