Seal forced in pipe
Seal forced in pipe
(OP)
Gents,
I hope that today problem will be simple for a mechanical engineer, but trust me I'm a poor chemical engineer so don't take anything for granted
Well ... we're speaking about an annulus-type seal cup which is forced inside a pipeline having an internal diameter smaller than the diameter of the seal cup (see attachment drawing). Seal cup is composed by an elastic material (say a plastic material) and annulus is fixed in the inner part. Of course, we know all the data about materials, dimensions, etc.
My questions are: what is the generated force of the seal against the wall? Is it possible to have an analytical solution (and what assumptions in this case)?
To make the problem more interesting, two are the different configuration I'm looking for, i.e.:
Thank you in advance for your attention and help.
I hope that today problem will be simple for a mechanical engineer, but trust me I'm a poor chemical engineer so don't take anything for granted

Well ... we're speaking about an annulus-type seal cup which is forced inside a pipeline having an internal diameter smaller than the diameter of the seal cup (see attachment drawing). Seal cup is composed by an elastic material (say a plastic material) and annulus is fixed in the inner part. Of course, we know all the data about materials, dimensions, etc.
My questions are: what is the generated force of the seal against the wall? Is it possible to have an analytical solution (and what assumptions in this case)?
To make the problem more interesting, two are the different configuration I'm looking for, i.e.:
- when p=0
- when p>0
Thank you in advance for your attention and help.
Matt17
Process Engineer





RE: Seal forced in pipe
At a basic level, the force will be the pressure plus any mechnical force from bending of the material.
All pretty negligible stuff for a steel pipeline.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Seal forced in pipe
thank you foryour interest. Yes, of course it's very close to a pig, you're right ... my interest to this problem is that I want to know exactly the mechanical force from bending of the material that you have mentioned, however my mechanical knowledge is not enough to analyze this kind of geometry (i.e. annulus fixed in the inner part), but I hope that the axial symmetry can help.
Of course this is not a problem for the pipeline, but my interest is to study the behavior of the seal inside the pipeline.
I hope that this problem could be such simple to have an indication of an analytical solution.
Thank you and Regards,
Matt17
Process Engineer
RE: Seal forced in pipe
A scale model won't be a linear relation to the real size since the stiffness of the ring is geometric.
RE: Seal forced in pipe
thank you for your time. I understand you suggest a trial with something closer to the real problem. However, what about if I want find the solution on the paper? Can you indicate me a reference (also a scholar reference like a book) with a similar problem?
Matt17
Process Engineer
RE: Seal forced in pipe
If you can expand on why you want to know this, you might get a bit more interest.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Seal forced in pipe
Again, my interest is to study the behavior of the seal inside the pipeline and, in detail, the force to push the item.
Matt17
Process Engineer
RE: Seal forced in pipe
As it wears or is incorrectly sized this diff pressure can fall or rise accordingly.
I still don't know what ypu're trying to do, but hope this helps.
LI
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way