Worthington hydro

[rjack321]

Why does everyone think the round-out requirement (to pass that is, not via DOT) is a function of the galvanizing?

It has zip to do with galvanizing and everything to do with the fact that these are exemption series tanks. Lightly built, yet tested at a whopping 5250psi. So duh they stretch like mad and need to be "pre-stretched" in order to pass.

3AA "lp" tanks are massively overbuilt and don't need any roundouts to be tested at a sedate 4000psi. Or even at higher pressures for the 3180psi+ rated ones.

 

[knowone]

Tank galvanising is not galvanising at all.


IT IS THE APPLICATION OF ZINC PAINT INVOLVING HEAT.

 

[Scott L]

how do you provide documentation that the tanks have not been abused?

You can't but it seems to work anyway...

 

[knowone]

why can't correctly galvanized their cylinders so we can be done with all this nonsense?

oops.

 

[drdaddy]

I have 7 Worthington and PSI HP/3442 steel tanks. 4 have been through hydro and not failed. I am sure the next 3 won't either. That is because I won't let idiots hydro my tanks.

There is only one shop that I will take them to. They used to sell PSIs and now Worthingtons and I bought some of these tanks from them. They have used the same hydro facility for years.

I believe that most (all) of the failures you are hearing about are due to the incompetency of hydro testers. Again, I don't let idiots (myself being the exception ) mess with my equipment.

 

[keyshunter]

My PST 119's were hydroed by Safe Air Systems in N. Carolina with no problems.

 

[Luis H]

Why does everyone think the round-out requirement (to pass that is, not via DOT) is a function of the galvanizing?

It has zip to do with galvanizing and everything to do with the fact that these are exemption series tanks. Lightly built, yet tested at a whopping 5250psi. So duh they stretch like mad and need to be "pre-stretched" in order to pass.

3AA "lp" tanks are massively overbuilt and don't need any roundouts to be tested at a sedate 4000psi. Or even at higher pressures for the 3180psi+ rated ones.

That is incorrect. I have had three 3AA steel 72's tanks fail because the hydro facility that I was using at the time didn't follow the the pre-test procedure. They did buy me three replacement tanks.

The round out procedure is required by PST for all their galvanized tanks. You can read the requirements... there are several links to it.

My LDS (they are also a hydro facility) and myself (I have run a couple of hydro stations) have noticed a huge difference in the test results of all steel tanks if they follow the round out procedure.


BTW: 3AA steel tanks are not massively over built. They are built to a code that specifies the the allowed testing wall stress of 70,000 psi. The wall stress design of 3AA tanks is the same no matter if the working pressure is 1800 psi or 3000 psi (there are 3AA tanks built to both pressures and many other pressures).

The wall stress design of the Special Permit tank is different, but that is just part of the design.

 

[captain]

Here it is again for the millionth time.
Not following the round out procedure will invalidate the warranty on PST tanks, I think Worthington is the same. It covers all hot dip galvanize tank not just special permit tanks.
If you don't make sure the hydro tester follows it don't complain if they fail.

 

[rjack321]

Here it is again for the millionth time.
Not following the round out procedure will invalidate the warranty on PST tanks, I think Worthington is the same. It covers all hot dip galvanize tank not just special permit tanks.
If you don't make sure the hydro tester follows it don't complain if they fail.

Of course PST blames the galvanizing. But its complete malarky. Thousands of Norris and Worthington 3AA cylinders are also hot dip galvanized yet don't need a round-out to pass. The only cylinders consistently failing due to the lack of a round out are exemption tanks.

 

[rjack321]

BTW: 3AA steel tanks are not massively over built. They are built to a code that specifies the the allowed testing wall stress of 70,000 psi. The wall stress design of 3AA tanks is the same no matter if the working pressure is 1800 psi or 3000 psi (there are 3AA tanks built to both pressures and many other pressures).

The wall stress design of the Special Permit tank is different, but that is just part of the design.

Well there are at tens of thousands of 3AA tanks on their 10th hydro and least a few hundred 3AA tanks close to their ~20th hydro (100yrs old!). 3AAs just don't up and fail on their first hydro like the exemption and 3AL tanks occasionally do. Consisently lasting a couple of lifetimes = "overbuilt" to me. I think Henry Ford had the same definition.