Pipe connection
Pipe connection
(OP)
Realizing that butt welding or bolted flanges are the traditional methods for joining pipe, I want to ask about the structural integrity when using an alternate method.
I have two 40' pipes. 10" diameter with a .135 wall thickness (10 gauge). I want to join them (end to end) with an inner sleeve - again, using a custom made 10 gauge inner sleeve pipe, 4' long (providing a 2' overlap). Will I maintain the structural strength of the joint using this method? I will be raising the two joined pipe to an upright position which will, of course, put stress on the joint.
My question only concerns the structural integrity of the joint - not the method of raising the structure. :)
Thanks,
Dale
I have two 40' pipes. 10" diameter with a .135 wall thickness (10 gauge). I want to join them (end to end) with an inner sleeve - again, using a custom made 10 gauge inner sleeve pipe, 4' long (providing a 2' overlap). Will I maintain the structural strength of the joint using this method? I will be raising the two joined pipe to an upright position which will, of course, put stress on the joint.
My question only concerns the structural integrity of the joint - not the method of raising the structure. :)
Thanks,
Dale






RE: Pipe connection
RE: Pipe connection
RE: Pipe connection
RE: Pipe connection
But, it is still very difficult to discuss your splice meaningfully, when you won't discuss some of the worst loading it might see. These various loadings will dictate how the joint is designed, the number, size, spacing of bolts, shell material thicknesses, etc. The fit-up btwn. the 10"dia. I.D. and the sleeve O.D. must be very good and very tight or you will likely be inducing the start of some wrinkles (crimping) in one part or the other part during the bolt-up. These wrinkles might be the starting point for a buckling condition. And now, the bolt forces are discrete high stress points in the shell structure, never a good condition. You have discontinuities at the lower and upper bolting details, some joint slip to really bring all the bolts into play, bolt to thin sheet bearing to deal with, etc. Furthermore, how do you get inside a 40' long 10" dia. pipe to apply the nuts, washers and bolts? Are contoured washers required for good fit-up and tightening and holding power, both convex and concave, one of each at each bolt?
What you are trying to save in field welding, shop applied bolt flanges, or transportation problems, might be outweighed by the difficulties of tight field assembly, bolting difficulties, and design problems.
RE: Pipe connection
Loading was bending moment only.
The unexpected result was that the joint may be stronger than the individual pipes...assuming sufficient overlap...
In the overlap the primary mode of failure for the outer pipe is to oval vertically while the inner pipe is trying to oval horizontally and tend to act to cancel each other out forcing a secondary type of failure..ie. chrushing , splitting etc.
The weak area seems to be just outside the overlap on the smaller pipe.
It was too complicated to put any numbers on it but left me with some degree of confidence that the weak area was in the weaker pipe from typical bending moment.
RE: Pipe connection
Regards,
Mike