Flooded tank, now what?

[northernone]

Finished a freshwater dive with a half cup of water in an aluminum tank. Removed the valve, hot water flushed it, now drying it in a breeze. Anything else I need to be doing? It's a tank I do transfills on.

Thanks,
Cameron

 

[Bob DBF]

It worked for an Al tank I cleaned after it was contaminated, back in '80, except I had to use soap to remove an oil film and then rinse. Tank had no issues and was finally scrapped in the late 2000's when the dive shop quit filling that bad alloy tank. Since I have more tanks now, I would blow out the tank with clean air instead of waiting for it to dry on its own.


Bob

 

[guruboy]

You sucked the tank dry (or should I say wet)?

 

[northernone]

You sucked the tank dry (or should I say wet)?

I needed to bring an unneeded reg along with me (didn't want to leave it on shore for safety) so I attached it to an nearly empty pony, butt mounted. Must have freeflowed and I had the valve open ( per my habit)... Come to think of it, normally a tank keeps some pressure on it, not sure how I fully drained it. Hp leak perhaps?

 

[Diver0001]

I needed to bring an unneeded reg along with me (didn't want to leave it on shore for safety) so I attached it to an nearly empty pony, butt mounted. Must have freeflowed and I had the valve open ( per my habit)... Come to think of it, normally a tank keeps some pressure on it, not sure how I fully drained it. Hp leak perhaps?

In a free flow, a modern regulator will empty a tank to the point that if you take the reg off and cover the opening of the valve with your thumb the pressure is too low to squeeze past your thumb. If the reg is open during a dive when this happens and the seal is not good then a significant amount of water can get in the tank, especially while at depth.

For example, I once had a dive with a rental tank and every time I tilted forward I got water in my mouth. At first I didn't know what was happening but I figured out during the dive if I didn't tilt forward it didn't happen so I swam slightly vertical for the whole dive. During this I formed a theory about what might be the cause and after the dive was over I hung the tank upside down and opened the valve and water shot out for maybe 5-10 seconds before it stopped. There must have been several liters of water in the tank.

As for what to do, I would say get it visually inspected and learn from this.

R..

 

[rhwestfall]

You can aid things a bit by inducing a flow of very dry (from another scuba tank) into the inverted tank. Take a second stage off the hose, and push the hose a good ways up in the tank, and blast for a bit.

 

[northernone]

Thank you all.

Great suggestions and thank you for confirming the course of action. I sacrificed half a tank of dry air via a LP hose to blow dry the tank and ran some air via transfill through the bare valve.

Passed visual (freshly washed as it was and squeeky clean) I'll have another look in a few weeks to assure myself it's as dry as it should be and not oxidizing.

Relubed the oring and filled her (thanks to SB for the idea of connecting two regs via the HP hose for tank balancing, with a cascade it's great for filling pony). Back in service.

Glad it wasn't salt water in a steel. I don't have a tumbler setup yet.

Regards,
Cameron

Still puzzled at it how the water ingress happened. The reg is from the 70s and normally gives a few more breathes when returning from depth empty. Orings good...

 

[Couv]

If water made it way all the way into an empty tank with a regulator attached you also have the task of disassembling, cleaning, and rebuilding the regulator.

If it's a piston reg, water intrusion shouldn't be a big deal-I don't know if the same can be said re a diaphragm reg.