Skipping Hydro

[captain]

Other than it being frozen to the point you can't open or close it or it leaks there isn't anything else that could happen. Unless you could find a current valve that had any parts common with it I don't think you could find any parts anyway. I have several 40 to 50 year old valves with original parts. Most of those old valves don't have any O rings just a teflon packing that last just about forever.
Just take the wing nut retainer off and the wing nut, clean off any corrosion and put a bit of lube between the wing nut and the valve body and change the burst disc to the new type and you should be good to go.

 

[UaVaj]

If it is filled to the proper pressure with dry gas and is not subject to fire or corrosion then it shouldn't blow up for the next 500 years or more.
How does the hydro prevent it from blowing up. The hydro merely says that nothing in the last 5 years has altered the strength of the tank.
I have tanks that have been under pressure for 50 years that at one time had been out of hydro for ten years or more when I was not using them and are now back in hydro.

In reference to what is in bold above. It is safe to say that: Aside from the legal stand point, if you know the history of the tank (where it is stored all it's life, if it was ever overfilled, how many times it was filled, if it was ever drop/abused), a hydro is not neccessary.



Everyone - thanks for all the great info.

I will get it hydro next year when it comes due and then sell it. I like to regularly swap out used stuff for new stuff even if the new stuff are exact replacement. For whatever it is worth - it is for my peace of mind. Afterall - this is life support equipment.

 

[captain]

In reference to what is in bold above. It is safe to say that: Aside from the legal stand point, if you know the history of the tank (where it is stored all it's life, if it was ever overfilled, how many times it was filled, if it was ever drop/abused), a hydro is not neccessary.




Everyone - thanks for all the great info.

I will get it hydro next year when it comes due and then sell it. I like to regularly swap out used stuff for new stuff even if the new stuff are exact replacement. For whatever it is worth - it is for my peace of mind. Afterall - this is life support equipment.

Using the above parameters I wold say a yearly visual inspection will tell you more about the condition and safety of the tank than a hydro.

Several years ago I bought a set of Voit steel twin 50's with an original hydro date of 1961 and no later hydros. They were absolutely like new both inside and out. There was no indication they had ever been used. There was a tiny bit of green patina in a few spots on the manifold from atmospheric moisture over 45 years. I had no concerns about filling them without having them hydroed and did.

 

[UaVaj]

KABOOM. Can someone explain - WHY does a tank typically blow up when filling? What are the physical effects that are going on inside the tank?

 

[Kevin Carlisle]

Short answer is the metal is stretching.. It expands when filled and retracts as the pressure drops. I believe this is called a cycle on the tank.

 

[fnfalman]

Short answer is the metal is stretching.. It expands when filled and retracts as the pressure drops. I believe this is called a cycle on the tank.

Fatigue failure. It happens to all metal subjected to forces, the question is when and that's where the hydro test (and other tests) come in - detecting the failure before it has deleterious effects on the personnel.

But in the end, you're responsible for your own equipment. Overfill, underfill, VIP, no VIP, hydro, no hydro, it doesn't make a difference to me.

 

[Kevin Carlisle]

Fatigue failure. It happens to all metal subjected to forces, the question is when and that's where the hydro test (and other tests) come in - detecting the failure before it has deleterious effects on the personnel.

But in the end, you're responsible for your own equipment. Overfill, underfill, VIP, no VIP, hydro, no hydro, it doesn't make a difference to me.

Ok your answer is shorter

 

[AfterDark]

Technically speaking, filling a cylinder that is out of hydro and then transporting it on public highways is illegal.

This is the second thread asking about filling procedures. Maybe you should get some training before using your compressor. Also make sure you have it setup correctly.

Why would you sell used tanks and buy new ones just because they need hydro??

Seems to me he has no idea what he's doing. Also your the 1st one to note that there is law is involved. If the tanks aren't transported they don't require hydro. If however you want to travel the highways with them they require hydro, it's not optional. You leave yourself open if God forbid someone hit your car, broke the valve on a hydro expired tank, and people got hurt. Does the term federal prison mean anything?

 

[AfterDark]

I do not think that the DOT has any authority over private individuals who are transporting their own cylinders that they filled themselves. Back when it was ICC you had to cross state lines, that may still be the case, I'm not sure.

INTERSTATE HIGHWAYS built with federal $$$ they have the last word. If you want to trasnport pressure vessels on the interstates then hydro is a must.

 

[rjack321]

INTERSTATE HIGHWAYS built with federal $$$ they have the last word. If you want to trasnport pressure vessels on the interstates then hydro is a must.

Nope. Must be involved in commerce. Privately filled cylinders are not involved in commerce and not subject to DOT regulations.

You could build your own cylinder if you had the skills and capacity, wouldn't be illegal unless you used it in commerce.