Large Volume Pressure Testing

[John.I]

Hello,

We have a requirement to pressure test some large volume cylinders (80 m^3) using air however there are some concerns regarding the magnitude of stored energy in the cylinders at the test pressure, which if released in uncontrolled conditions could have detrimental effects to surrounding systems and personnel.

In order to mitigate this we are looking into reducing the volume of the pressurised gas by installing some packing / space filler into the cylinders for the duration of the test. I have searched the deepest darkest depths for companies on the internet that are able to supply a product suitable for this application, without much success. Is anyone aware of anything suitable?

Many thanks

 

[dgallup]

Sand? Most people test with water or hydraulic fluid for safety. How high is the pressure? Can you put the cylinders in an unoccupied cement block building or pit to contain the potential shrapnel?

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[SnTMan]

Jonh.I, maybe something like this?

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[MintJulep]

Water.

 

[John.I]

It is not possible to test with water - testing with air is the constraint.

The test pressure is 50 psi.

Mike, thanks for the link but using balls will not be feasible as installing / removing them may prove some difficulties due to the size of the tubes.


Thanks

 

[LittleInch]

Solid PE or nylon bars?

Give us a bit of clue here - what does your cylinder look like? What is the manhole or pipe entry size?

Where do these tubes suddenly come from?

This is like trying to see something through a letter box...

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[1gibson]

Fill it with a piece of string first.

 

[rb1957]

it is common to fill aircraft pressure test specimens with solid foam blocks to remove most of the volume.

water would also work, but be messy.

sand (in bags) would also work.

anything relatively incompressible.

another day in paradise, or is paradise one day closer ?

 

[Compositepro]

How about water in a bag?

 

[John.I]

Thanks for the feedback guys, I cannot provide any further details on the application itself as its restricted information. Essentially these are HY80 structural steel tubes with a 3 mm wall thickness, and are orientated vertically about axis of tube. The manhole entry size at the top of the tube is 9ft.

Solid foam blocks would be a feasible option, are you aware of any suppliers in the UK?

 

[berkshire]

Hydro forming machines used Urethane bladders that enabled the machine to exert a force of 6000psi. Using hydraulic oil. Is there a way to install and remove such a bladder?
B.E.

You are judged not by what you know, but by what you can do.

 

[John.I]

It would be possible to install bladders by lifting them into the tubes, however this does seem like an 'over-engineered' solution. The simplicity of foam blocks would make them more favourable.

 

[LittleInch]

"Solid foam"???

Not sure how well foam panels will resist air pressure. Think you want solid PE or nylon.

Can you just sketch this thing a bit if you can't post actual drawings as I can't visualise your cylinders and tube arrangements.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[rb1957]

it does a very good job of it. Mind you my experience is in aircraft fuselage, so about 20psi; if your pressure is considerably higher then it may be a question to ponder ...

googling "foam blocks uk" got several promising hits.

another day in paradise, or is paradise one day closer ?

 

[SnTMan]

John.I, don't know, really, what kind of configuration or access you've got, but my thought was some kind of plastic balls or beads that you could "pour" in and "drain" out.

Regards,

Mike



The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[rb1957]

loose fill (like plastic balls or sand bags etc) would have a problem of hydrostatic loading if the cylinder is vertical.

another day in paradise, or is paradise one day closer ?

 

[gerhardl]

What about sawdust, blown in sucked out? Cleaning problem? Big-bag held inside?

 

[ScottyUK]

There have been some devastating explosions involving sawdust, wood flour, etc. Something which seems innocent but which is really something handle with care.

 

[gerhardl]

Thank you, ScottyUK! I stand corrected!

Worst case could be a pressure overload, 'correct' mixture of dry and fine-grained sawdust with air and an ignition source inside a (partly) intact container. I should have seen this probability myself!

 

[itsmoked]

Presumably this thing is engineered and people are staking their reputations on them. If they have to handle 50psi then they likely will. Unless, this is some cobbled up 'thing' made by non-approved or untried methods, I'd clear the vicinity, perhaps sand bag anything nearby that is precious and have at it with air. Maybe do it at midnight if it helps remove ALL the people.

Keith Cress
kcress -

http://www.flaminsystems.com