pressure vessel testing

[Neil WyattModerator @neilwyatt]

Posted by Michael Gilligan on 18/01/2016 11:20:00:

Posted by Neil Wyatt on 18/01/2016 10:48:48:

Such as a DeHavilland Comet

**LINK**

Thanks!

When I was a boy I wanted to work at the RAE doing exactly that – putting together crashed planes to work ou what had gone wrong.

Neil

[David JuppParticipant @davidjupp51506]

Michael,

RE Sodastream cylinders. I have no specific knowledge but;-

1. Just because it is possible to design an item in steel with infinite fatigue life, that doesn't mean that approach was taken – could just as easily have been designed for a safe life of a certain (large) number of cycles.

2. Steel is generally more vulnerable to corrosion than Aluminium is, internal corrosion of steel vessels is an inspection headache. External corrosion is a problem too.

3. Probably other factors to consider too, like resilience when dropped or otherwise mis-handled.

Without more detailed information it's difficult to reach any conclusion about any potential differences in safety levels between cylinder types and their associated inspection regimes.

[Michael GilliganParticipant @michaelgilligan61133]

Thanks, David … That's useful comment.

The old SodaStream cylinders were very heavily built [for their capacity] and, rightly or wrongly, I feel 'comfortable' with them. … They are a useful benchtop source of compressed gas.

If I understand correctly, the move to Aluminium coincided with the change to a proprietary screw fitting and the introduction of some strict licencing rules. [probably as a defence against Product Liability claims]

Despite which: Adapters are widely available, and therefore people can and do refill the Aluminium cylinders.

MichaelG.

.

Edit: This is the sort of 'information' that worries me …

[quote]

• Carbonation Cartridges. This is the biggie. The cartridges are reasonably easy to get and exchange for a refill (at some stores, but generally online) in the US, UK, much of Europe, Australia and New Zealand.  In other places, you’re likely to have to refill them yourself (see video at the bottom of this article on how to do it — this is what many cruisers in the Caribbean and Mexico do).  You can getb systems that use “small” cartridges good for making 60 liters of soda or “large” cartridges good for 130 liters — and the interesting thing is that the SodaStream units are the same size, and some can use either size cartridge.  You cannot take carbonators on an airplane (either in the cabin or in checked baggage) and they cannot be shipped by air.
• [/quote]
•  

Edited By Michael Gilligan on 18/01/2016 15:07:38

[jason udallParticipant @jasonudall57142]

Gentlemen.
It appears that you have discovered one of the important principles of modern life.

For example.
Design/ build /test vessel to given pressure both working and safety levels..
Readily achieved. ..

Negotiate “relavent ” standards.. ( esp. Identify said standards)…not so easy.

I have this from my day job with low voltage / emc/machinery “directives”…buckets of test houses that will take your (modest ) fee…
But sign off to a directive..nfc…”we just test the tests you ask for. .up to you to chose the test criteria”.and make the declaration. ..
* nfc …relates to low probability. ..

Edited By jason udall on 18/01/2016 15:43:18

[jason udallParticipant @jasonudall57142]

Love this forum sw

Edited By jason udall on 18/01/2016 15:41:49

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