How often do you need a tumble for a PST tank?

[drbill]

Based on my experience with two PST HP120 tanks dived under completely different conditions (one used on boats, one for shore diving), I'd say tumble them every 6 months!! Not entirely serious but the one used on boats failed VIP with serious rust 18 months after its last hydro. I won't use them. Your experience may differ of course.

 

[Leadking]

Totally agree!!!

It should NEVER be neccesary to tumble a tank. There are only two possible causes, and both involve people screwing up:

1. You empty your tank underwater.
2. LDS filled gas which didn't meed the required specifications.

You will not have rust if the gas is in compliance with regulations. Period.

 

[Texfrazer]

It should NEVER be neccesary to tumble a tank. There are only two possible causes, and both involve people screwing up:

1. You empty your tank underwater.
2. LDS filled gas which didn't meed the required specifications.

You will not have rust if the gas is in compliance with regulations. Period.

Actually, you'll probably have flash rust develop after the tank is hydro'd - almost certainly if the hydro isn't physically performed at a dive shop with their own setup. But, flash rust is not a reason to tumble - just to whip.