Hello people.

In the normal course of supporting pipework, we can use either welded or bolted shoes.

Now,as per PED, the welding of any attachment to the pipewall requires coded weldiers, so for time and money, we are switching to bolted shoes.

My question is this, what limitations do a bolted shoe have over a welded one?

I intend to use bolted shoes except where supports are required to resist forces, at which i will specify a welded shoe. (over say 3")


Thoughts please.

There's a good paper on this available from the sciencedirect site:-

Pipe-anchor discontinuity analysis utilizing power series solutions, Bessel functions, and Fourier series
Dennis K. Williams a, William F. Ranson
Nuclear Engineering and Design 220 (2003) 1 /10

A bit on the academic side, but good never the less.

Clamped on shoes or clamped on anything have some distinct advantages and disadvantages…

Advantages:
No or minimal welding… as you start working on alloyed pipes this can be a major consideration. Frankly welding anything on P91 to me is a daunting task.

Ease of assembly… easy to field jiggle for fit up..

Disadvantages:
Expensive…. Clamp-Ons are more expensive than a simple welded WT shoe and or saddles.
Availability…. Plate material is more readily available than pre-manufactured items.

Load Ratings…. The data for what load the clamp on can or can’t take may be hard to come by.


The bottom line for me is on anything but carbon steel I like em!