Worthington HP 100s failed first hydro

[Scott L]

Interesting. My first PST HP120 failed its second hydro due to over expansion (and yes, the test facility followed the proper testing protocol for those tanks). My second PST HP120 failed VIP within 18 months of its second hydro. Of course these are PST rather than Worthington cylinders.

It was thought that the first tank failed the hydro due to numerous hot fills at Casino Point. It was used almost entirely for shore-based diving. The second may have failed due to rust caused by water. It was used almost entirely for boat diving.

I only frequent LDS's with wet filling stations. One need not be an expert with metallurgy to discern less stress is placed on cylinders not to mention materially greater fills...

 

[Skooter]

I have never had a tank that failed hydro, but I have always been told that if the tank failed hydro, the facility will drill holes in it. Is that a myth or something the LDS authorizes when they take the tanks to the hydro facility?

According to the CFR you (the owner of the tank) must give permision for the cylinder to be destroyed if it fails the hydrotest. I/E holes drilled, threads destroyed whatever. If a facility takes it upon themselves to do this without your permission they may have to replace the cylinder that was destroyed. The test facility is only required to x out the dot numbers and tank ratings.

 

[Can't swim]

My guess would be that any LDS that would require you to sign a work order of some sort, has included small print that gives them permission to destroy said tank(s) in case of failure. That way you can't get it re-tested and you can't "make" them replace the tank(s) because the customer signed the waiver on the work order. And, you would more apt to purchase a new tank(s) from them.
Not what I'd call good business practice. But, from what I've read on SB there are plenty of operators out there that might practice their business as said above.

 

[carrielsal]

My guess would be that any LDS that would require you to sign a work order of some sort, has included small print that gives them permission to destroy said tank(s) in case of failure. That way you can't get it re-tested and you can't "make" them replace the tank(s) because the customer signed the waiver on the work order. And, you would more apt to purchase a new tank(s) from them.
Not what I'd call good business practice. But, from what I've read on SB there are plenty of operators out there that might practice their business as said above.

Interesting. I don't think I have ever signed anything when I have dropped tanks off for hydro. I think where I have always heard that the hydro facility drills holes in the tanks that fail in OW classes.

 

[Van Isle]

A small used compressor is probably cheaper than buying 2 new HP 100s.

Just saying.

 

[Skooter]

A small used compressor is probably cheaper than buying 2 new HP 100s.

Just saying.

It very well could be, but lets not forget why hydrotesting is required. But then again if someone wants to take that risk on their own it is a free country. I myself will continue to have my tanks tested so I have a little better odds of a major event not happening to me.

 

[Van Isle]

It very well could be, but lets not forget why hydrotesting is required.

DOT regulations certainly apply to tanks used in the US for interstate commerce. If that is your case, by all means. There is no law saying scuba tanks must be hydro'd to be filled. It is a SCUBA industry/dive shop "regulation."

Also, a tank fails hydro when it expands such that a little more water than acceptable is pushed in to a burette on the hydro testing rig at 5/3 or 3/2 working pressure. There's no catastrophic, Hollywood failure.

 

[Tug]

Contact these folks, they advertise that they do DOT hydro testing

Fire Equipment Inc
P.O. Box 414259
Boston,MA 02241-4259

I'm on my phone otherwise I'd check but I believe United Divers in Somerville also does hydro testing in house.

 

[Skooter]

DOT regulations certainly apply to tanks used in the US for interstate commerce. If that is your case, by all means. There is no law saying scuba tanks must be hydro'd to be filled. It is a SCUBA industry/dive shop "regulation."

Also, a tank fails hydro when it expands such that a little more water than acceptable is pushed in to a burette on the hydro testing rig at 5/3 or 3/2 working pressure. There's no catastrophic, Hollywood failure.

I don't mean to start an argument. There are enough about tanks and hydrotesting already, just trying to keep facts and urban myth seperate. As a certified hydrotest tech I am aware of what constitutes a failure during a test and how it is controlled in a way that is a non event even in the rare case of a full rupture. You are correct that once a cylinder expands/contracts outside of it's parameters it is taken out of service. This generally happens long before the cylinder gets to the stage of rupturing.But outside of that controlled environment if a cylinder ruptures it is anything but a non-event. So the post I answered was about skipping testing and filling their own tanks. I think it is only fair that people realize that is one of their options, but are the possible results worth saving @ $20 every five years.

 

[Indian Valley Scuba]

"XXX" out the serial number is the law.

Drilling holes, filing grooves in the threads, sawing the tank, etc. are not the law and open the tester to liability for damages unless specific permission has been granted.