Tank overfill = mini hydro?

[SCUBA482]

Shops that need to fill a lot of tanks should just get more fill whips. It's better to fill several tanks slowly at the same time than to fill them one at a time quickly. If shops were smart enough to abandon their water tanks, they would have plenty of room. The industrial gas industry has been doing this for decades. They usually fill 10, 20 or more cylinders at a time, never in water.

But also, shops should realize that if the tank gets to no higher than 130F, they can legally fill over the service pressure as long as the tanks are at or under the service pressure when cooled to 70F.

What's the catch on not filling tanks in water? If it helps to keep tanks cool then why not?

 

[Thalassamania]

It does not help to cool them, heat transfer is too slow from the gas to the tank for cooling from the tank to water to be meaningful. If you want cooling, an active intercooler between the final stage and the filling whip is where it is at.