Force to collapse a tube

[Djordje Jaksic]

Hello all,

I have a small plastic tube, and I want to know how much force is required to get it to buckle at just one point. This tube will be blocked/closed at one end and I will be applying suction at the other end, and I want to know how much pressure will be required to make to tubing collapse.

 

[LittleInch]

Needs some more info here.

Small - How small? some dimensions including wall thickness required

"plastic" - too vague. PE, PVC, plastic flexible tubing?

buckle? Do you mean collapse from external pressure? Buckle tends to mean failure when something is bent. A diagram / sketch / photo always helps

Also force is the wrong word - Do you mean negative pressure?

Often tubing or plastic pipe needs to have an initiation ovalisation to get it to collapse in a set place.

but you only have max 1 bar differential so it might not collapse at all...

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

 

[hacksaw]

If surgical tubing is at issue, peristalic pumps operation provides guidance. It is hardly a matter of force, rather adjustment for proper clearance

 

[racookpe1978]

Well, what is the maximum vaccuum you can pull with your test rig question?
What fluid? (A condensate (water, alcohol, or liquid gas) will begin vaporizing as internal pressure in the tubing goes down = vapor pressure controls.

Straight, simple large 90 or u-bends, or in an instrument rack with many bends?

 

[IRstuff]

I don't think it matters what vacuum could be pulled; assume that it's perfect, but unless the aspect ratio of diameter to wall thickness is much higher than probably 20:1, it's unlikely to collapse.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[Compositepro]

IR, I think you need to reword that statement.

 

[IRstuff]

Thanks, I got interrupted in the middle and lost the bubble.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[Tony_M]

you could use the external collapse pressure calculation for submerged pipelines (pressure difference usually greater than 1 bar). gives the same result for external pressure or internal vacuum.

try

http://pipeng.com/index.php/ts/itdmotdiam008f/