Hi. I've seen a hole in a saddle t 3

[treatwater]

Hi.
I've seen a hole in a saddle typs around pipes, what is this? Is there any reasonable explanation?

 

[BigInch]

Submarines and eggs seem to do rather well with outside pressures. As I recall curves, circles, spheres and arcs are the strongest shapes of all, whether the pressure is on the inside or the outside.

 

[SwinnyGG]

Seems to me the hole is there to prevent the repad/pipe wall interface from becoming an unintended pressure vessel in the event of a leak inside the weld between the two parts. Depending on the service pressure of the pipeline in question, pressurizing the pad interface could have very bad consequences.

 

[rconner]

Agree that "curve" helps for internal or external pressures, but thin or weak pipes are not as stable in an of themselves re internal vs external pressures. E.g. could it not be that a 60" 0.5" mt 42 ksi YS pipe might readily handle say 525 psi internal pressure at 75% of YS, but be in danger of collapse or buckling (if not internally pressurized at the same time or externally stabilized, with ring girders or earth) at only say 30 psi or far less uniform external pressure? Of course as well, only small sectors of particularly large vessels or pipes really don't have much of a "curve" to them, and I guess even quite large pipes are most frequently a little thinner than submarines. All have a good weekend.

 

[itsmoked]

That fits with:

If the holes are plugged, the plugging material used
shall not be capable of sustaining pressure between the
reinforcing plate and the vessel wall.

Keith Cress
kcress -

http://www.flaminsystems.com