How many fail hydro?

[jcwalsh]

Info online says 10-12% of tanks fail hydro which seems really high. How many of those are aluminum or rental tanks? Is there a steel vs. Aluminum failure %?

 

[Divin'Papaw]

Info online says 10-12% of tanks fail hydro which seems really high. How many of those are aluminum or rental tanks? Is there a steel vs. Aluminum failure %?

That does seem high. In my limited personal experience having owned up to 20 tanks at any given time over the past 17 years, I've never had a single tank fail hydro. That includes a mixture of steel and aluminum.

I too would be curious to hear from those who have experience with alot more hydros than my limited data set.

 

[Johnoly]

Info online says 10-12% of tanks fail hydro which seems really high.

Remember that scuba tanks are a teeny tiny fraction of all the tank hydro's completed. Most beverage/welding/O2's fail from valve damage being dropped or seized (not REE) according to my local hydro guy.

 

[tridacna]

At the shop I worked at, we sent about 60 tanks/month for hydrostatic testing. One failure in 3 years.

 

[lexvil]

Probably 100% it’s just a matter of how many years.

other than real abuse it’s or it seems more likely a faulty tester than a faulty tank that leads to condemnation.

 

[rob.mwpropane]

I learned a lot about hydro after I had a tank fail. I believe it comes down more to the tester then the tank. I really feel like if a tank fails they should run it through again just to make sure it didn't need the pre-stretch done for longer. I'd really like to get mine tested again at some point. I found out later that the place I went to has tanks fail from time to time... that's a bummer.

I believe @Tracy said in all his years he's only seen one tank fail. Can't remember his actual #'s, but he has a lot of tanks.

 

[rjack321]

Had an aluminum medical o2 bottle (D size) fail hydro spectacularly once. But never a scuba tank despite a couple decades and a whole bunch of tanks sent in

 

[SpeedyJ]

Dealt with hoop wrapped SCBA bottles in my past life, even the ones that had easy lives as escape respirators stuck in cabinets didn't have a good track record at hydro.

 

[broncobowsher]

I believe a bad test is more common than a bad cylinder. Notably the cylinders that have odd testing requirements.

I was gifted an aluminum cylinder that had failed. Actually failed the pre-hydro inspection as the dent on the side was clearly visible on the inside. So abuse.

 

[rhwestfall]

I have somewhere north of 30 tanks, and have been certified for nearly 35 years. I lost one (lp steel) at the first requalification that was because of incompetence by the tester. Manufacturer reviewed the test, said it was done "incorrectly", but no recourse. The tester used a minimum time instead of "stabilization" to determine failure. Improper, but not "wrong".... Yep, they suck.

They are also too lazy to provide "+" ratings on tanks with the values stamped on the tank....