Skipping Hydro

[UaVaj]

What are the long term / short terms effect(s) of skipping hydro?

Tank in question is: Worthington Steel HP120 with original hydro of Sept 05.

I have my own compressor.

 

[Kevin Carlisle]

Well the word KABOOM comes to mind.. Without a hydro you would not know if there was a defect in the cylinder.

 

[UaVaj]

KABOOM - isn't that a little extreme?

Please give some details and/or links to your claim. What tank(s) has gone KABOOM due to lack of hydro.

Afterall a hydro is: testing the average material elasticity of the complete cylinder.

If any tank(s) gonna go KABOOM, it should be so during hydro. That is when the tank recieved the most pressure. Pressure way way beyond rated spec.

Are hydro facilities blowing up all over the place?

 

[mrfixitchapman]

Hydrostatic test - Wikipedia, the free encyclopedia

Especially read this section

Testing procedures

That's why a tank that fails a hydrostatic test doesn't kill everybody in the building.

DC

 

[Kevin Carlisle]

Go read. The tanks actually split when they burst. Not really like a bomb but still deadly. There are several reports on here. An Australian guy lost a hand about 2 months back. No NOT extreme. Hydro is done to try and find the weak spots. Manufacturing the cylinders is not an exact science, no gaurantees that a bad spot will not show up after 500 to 1000 fills.

Bank tanks at a dive shop blew while I was on their boat a few months back, I had just left their shop. So if your hardheaded enough to do it with all the warnings and threads on here about it go ahead..You buy a compressor but then are too cheap to get a hydro every 5 years, something is backwards there. Thats like a 10 dollars a year over 5 years, seems cheap for peace of mind. Not to mention showing you care about the safety of people around you.

There could also be some DOT penalties. Its a DOT requirement but I have never had them check my tanks. Dont know if anyone else has but I never heard of it. So yeah I stand with KABOOM.

 

[rsilva708]

A hydro should determine the possibility of a problem which would cause it to fail before it happens. Just because it passes 5 years ago doesn't mean it would pass now. I personally would never fill a tank out of hydro. You have your own compressor so I guess it's your own choice, but I would not want to be near it if it did have a problem while filling.

 

[dannobee]

I have my own compressor and still have my tanks hydroed. I also VIS them at least once a year to make sure everything is copacetic.

In reality a steel tank very rarely fails hydro (irrespective of the PST tanks and their required trickery when performing hydros). Even when they do fail hydro it almost never fails catastrophically. More like the cylinder expands more than it should.

 

[captain]

I have been filling my own tanks forever and have skipped hydros but I know the history of all of them and I do yearly inspections. I would not fill a used out of hydro tank I bought that I have no history on it without first getting a hydro. One that is still in hydro I may fill after an inspection.

 

[UaVaj]

Hydro is done to try and find the weak spots. Manufacturing the cylinders is not an exact science, no gaurantees that a bad spot will not show up after 500 to 1000 fills.

So if your hardheaded enough to do it with all the warnings and threads on here about it go ahead..You buy a compressor but then are too cheap to get a hydro every 5 years, something is backwards there. Thats like a 10 dollars a year over 5 years, seems cheap for peace of mind. Not to mention showing you care about the safety of people around you.

Bad spot shows up after 500 to 1000 fills?

I have 6 HP120 (don't ask me how I ended up with six - long story - however, it has proven to be very convenient) and I just log my 100th dive a few months ago. That mean each tank has seen about 20 refills if that.

I am simply deciding if: (1) I want keep it as is or (2) to sell it before the hydro is up and buy 2 new replacements.

I just do not see any reason to get it hydro when the tanks are practically perfect and have only seen 20 fills since new. Not to mention the hassle of getting it hydro.

So if the effect of skipping hydro is beyond acceptable reasoning, then option 2 it will be.

 

[rsilva708]

Bad spot shows up after 500 to 1000 fills?

I think what he was saying is that there is no way of telling when a bad spot in the tank may show up.