Fills dry or in water bath?

[tomfcrist]

I don't think anybody fills much slower than I do (over 3 hours). I still get a fair amount of pressure drop after they cool. I have my compressor shut down at 3800 LB and the tanks drop to 35-3600. I generally don't wet fill but when I do it makes a difference.

300psi drop? Sounds legit. I would say that's acceptable. Overfill your desired pressure and let it settle.

That would be really really slow. I take 30 or 40 minutes to fill an hp 100. That still builds enough heat in the steel to lose around 300 psi after the tanks cool, which I later top off. Way easier to me than a tank bath but I have the convenience of 4 whips and a cascade.

Same as above.

 

[Flycaster]

Maybe Wookies do it differently on their planet

 

[TrimixToo]

In my horned viking helm and tutu?View attachment 428428

Oh, man. Some things you just cannot forget seeing....

 

[BRT]

Why not go right to the source? Psi. Or Professional Scuba Inspectors, they certify individuals to inspect, clean, fill, and just about everything else involving tanks. I'll save you the time and provide the link. Then tell me if you still think the same way about wet filling your tanks. At the end of the day it is the person filling them that risks the most.

PSI-PCI - Filling Cylinders In Water - Time to Review

That article is kind of questionable
Which metals conduct heat best
Common metals ranked by thermal conductivity
Rank Metal Thermal Conductivity [BTU/(hr·ft⋅°F)]
1 Copper 223
2 Aluminum 118
3 Brass 64
4 Steel 17
5 Bronze 15
I don't think the thinner walls of a steel tank make up for the faster heat transfer of aluminum.

Then you have the main point of the article which was "If you keep the temperature down you may get overfills" Utter nonsense.

And then the part about hydro tests not being very good predictors of tank failure. Huh? How many tank failures are there? Seems hydros are working quite well.

 

[swimlikethefish]

I'm not a metallurgical scientist, nor a professional in any capacity when it comes to tanks. But through basic research it would seem to me that wet/hot fills, are not the way to go. What's the rush? Why not fill them at a normal rate and then wait for them to cool before topping off? Everyone seems to be tied up in the instant gratification. How many times have you actually filled a tank hot because you were going to jump back in within 2 hours? Just plan your fills and you won't have to risk a possible failure due to negligence. It isn't that hard.

 

[tbone1004]

I'm not a metallurgical scientist, nor a professional in any capacity when it comes to tanks. But through basic research it would seem to me that wet/hot fills, are not the way to go. What's the rush? Why not fill them at a normal rate and then wait for them to cool before topping off? Everyone seems to be tied up in the instant gratification. How many times have you actually filled a tank hot because you were going to jump back in within 2 hours? Just plan your fills and you won't have to risk a possible failure due to negligence. It isn't that hard.

dive shops don't have that luxury....

the tanks won't get anywhere near hot enough for the metal to be of concern....

 

[Wookie]

the tanks won't get anywhere near hot enough for the metal to be of concern....

They do on the planet Kashyyyk...

 

[tbone1004]

They do on the planet Kashyyyk...

*insert Wookie noises*

 

[BRT]

300psi drop? Sounds legit. I would say that's acceptable. Overfill your desired pressure and let it settle.



Same as above.

Remember that this is after filling the tank over 3 hours.

 

[MaxBottomtime]

How many times have you actually filled a tank hot because you were going to jump back in within 2 hours?

That happens on dive boats every day.