LP tanks

[Pete]

The cylinders supplied to the US market are different to those supplied to the European market. I do not know whether there are differences in wall thickness but the pillar valve threads are certainly different. Presumably metric versus dare I say 'imperial'.

Result, a brand new US DOT Faber will automatically 'fail' if presented for hydro here in the UK just as a European Faber would 'fail' if presented for hydro at a US test station.

With regard to pressures the steel cylinders marketed in Europe fall into 2 groups, 232 bar working pressure and for the last approximately 10 years or so 300 bar working pressure. In both cases that is the wp marked on the cylinders, not sure where you got the idea that European 232bar Faber were actually 200bar over filled to 232bar. The US cave policy of over pressing tanks tends not to occur over here. With 300bar cylinders readily available who needs to!

Plus of course we do not have burst discs but that is a whole other story.

Peter

With 300bar cylinders readily available who needs to!

You are aware that 300BAR is almost 4500psi?

Other than firefighter and paintball cylinders (fiber-wrapped aluminum), I don't believe I've ever seen a 4500psi cylinder. Perhaps you're thinking of E-series? They are 3442psi (232BAR).

Russell

Wait a second - are you from Connecticut or the UK?

[DeWayne]

You own a fair sized manufacturing company. You make these steel things that people put gas in. I guy comes along and says will you make me 500 of these thing about this tall? Sure you say but hey can I sell them to other folks I hear thay like these in America too. Sure the guys says.... But I hear the DOT in America only lets you fill them 3/4 of the way so you will have to build two types.......... Um ok I'll do all that R&D to meet a lower standard than here in Italy....... Sorry it don't make fiscal sense they make one cylinder and stamp one for America and one for the smart people. Of course then they go and lose their minds over the types of gas and want everyone to use a different valve for each one
I tend to believe they make one cylinder and label accordingly

It does not make a lot of sense to me either for them to manufacture two cylinders so similar yet different. But as you can see, there are those who insist that there are differences based upon the geographical market they are intended for, which is why I would like to read some sort of official technical document regarding this. The different threads is a new one to add to the list of why they differ.

[Cave Ranger]

I have an OMS catalog from early 2000-2001. That's back when they praised virtues and the superiority of the Faber LP tanks as opposed to HP Tanks from other manufacturers. Now they've done a complete reversal that I'm told has more to do with a falling out with Faber as opposed to an actual improvement in the tanks.
In this particular catalog the Tank Specs Chart gave a Working Pressure of 2640 which included a 10% overfill but rated all of the Tank's life spans as 10,000 Fill Cycles at 4000 psi. That gives the impression that you should be able to fill these LP Tanks to 4,000 psi 10,000 times but...........you probably shouldn't.
It's difficult to know what to believe as there are conflicting stories.
Maybe we should all just fill to what the Tanks max rating stamped on the tank and stop living so dangerously.
I've started wearing a Bomb Squad Suit just to ramp mine up to 3,800.

[Pete]

When I joined the forum I was living in Connecticut, now back in the UK. Just never got around to changing my profile.

As to pressures, yes 300 bar works out at about 4350 psi. The 300 bar steel cylinders have been pretty common over here for 10 years or so. Only problem when they first came on the scene was that the high pressure seats on some regs did not like the pressure despite in theory being cleared for 300bar. We use Apeks and absolutely no problem with 300bar

And if 300bar is not enough then the diluent flasks on certain UK military rebreathers are rated for 350bar!

Only problem with such pressures is that beyond approx 240bar the gas laws start to deviate a little. Result, our 12.5 litre 300 bar twins when 'full' contain a little less usable gas than the 7500 litres (approx 260cuft) you would expect.

Peter

PS. even at 300bar, still no burst discs!!!!

Maybe we should all just fill to what the Tanks max rating stamped on the tank and stop living so dangerously.

Mine don't have the max pressure stamped on them, just the turnaround pressure. Isn't that what 2400t means?

If turnaround is 2400, then we fill them to 3600.

[DeWayne]

Maybe we should all just fill to what the Tanks max rating stamped on the tank and stop living so dangerously.

Mine don't have the max pressure stamped on them, just the turnaround pressure. Isn't that what 2400t means?

If turnaround is 2400, then we fill them to 3600.

That means with a + hydro you would round up to 2700, which would make a 4000psi fill just about right :P I like the way you think Russell 8)

Darn, you misunderstood my joke. I was implying I saw the 2400+, and misread it to be 2400T, T for turnaround.

Yes, I understand a +hydro.

[DeWayne]

I fully understood your joke and the twist on the +, just rationalizing my own preferred fill pressure