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Calculation of Collapse Pressure for Perforated Pipes

Calculation of Collapse Pressure for Perforated Pipes

Calculation of Collapse Pressure for Perforated Pipes

(OP)
Hi all

Can you please guide me on how to calculate the collapse pressure of perforated Pipes.

My case is to make a 2mm thick Pipe (1500 mm long) to be used as a filter element with perforations. The wire meshes shall be wound around the perforated pipe.

Design pressure - 5 kg/sqcm(g), which shall be the maximum differential pressure across the Perforated pipe
Required No. of holes on Pipe = 1250
Hole diameter = 8 mm
Hole pitch = 13 mm, triangular pitch

Are there ready references ??

Thanks in advance

RE: Calculation of Collapse Pressure for Perforated Pipes

(OP)
Additional data (forgot to mention)

Flow is from outside to inside (external pressure design case of 5 kg/sqcm)
Material of construction of Pipe - SA240-304

RE: Calculation of Collapse Pressure for Perforated Pipes

What's the Od of your pipe?

Is 5 bar differential the maximum pressure outside, assuming zero inside and a fully blocked filter?

Is a fully blocked filter realistic?

The difficulty of this approach is why you normally go inside to out, plus it makes the capture of dirt a lot easier.

However assuming you're stuck with your design and flow and not bothered about debris, I think you will either have to model this in FEA or you may just make one and test it. Try a cylinder 1mm thick or 0.5mm thick and see if it holds up.

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

RE: Calculation of Collapse Pressure for Perforated Pipes

You also seem to have left out the diameter.

Never have run across a method to calculate the collapse pressure of drilled pipe.

Some observations:
[ol 1]
  • The movement of the media may have more force than the differential pressure. If the media in the tank shifts, it may break the pipe.
  • Usually people use larger holes in the pipe and rely on the wire mesh to do the filtering.
  • You can buy commercial products such as well screen. Collapse pressures are in the brochure. http://www.johnsonscreens.com/sites/default/files/...

  • /ol]


    RE: Calculation of Collapse Pressure for Perforated Pipes

    What about the mesh (or is this some some kind of fine wire screen?) - would this not collapse before the pipe does at 5kg/cm2(g)?

    RE: Calculation of Collapse Pressure for Perforated Pipes

    I would start by using an equivalent elastic modulus reduced in proportion to (p-d)/p=5/13 in your case.
    A justification to this is that a tube buckles by forming an oval (or a higher order waved shape), and longitudinal weak lines passing through the ligaments will be the source for bending to the collapsed shape.

    prex
    http://www.xcalcs.com : Online engineering calculations
    http://www.megamag.it : Magnetic brakes and launchers for fun rides
    http://www.levitans.com : Air bearing pads

    RE: Calculation of Collapse Pressure for Perforated Pipes

    I'd test it in a testing MACHINE.


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