Hello to everyone,

We are currently analyzing a large diameter pipe which is mainly supported with Spring Hangers due to large thermal movements resulting from the pipe's high operating temperature.

My question is whether we should model Rigid Elements at each supporting location to take into account the radial growth of the pipe, so as to define the actual hanger travel.

For example, assuming a 52" Stainless Steel pipe with 500 degrees Celsius Design Temperature, the radial growth of the pipe would be around 6mm.

Assuming that the node in CAESAR calculation which corresponds to a spring hanger moves 10mm down, it means that the actual hanger travel (attached on the top of the pipe) would be around 4mm down because of the pipe's radial growth.

Is my understanding correct?
Is this a standard approach when modeling such lines?

Any help/suggestion will be highly appreciated!

Alex

If the pipe routing and equipment attachments do not (or might not) possess enough tolerance to accommodate the 6mm of movement, then you should address it in some form.

You should also look into dual spring hangers attached at 90 degree and 270 degree locations on the pipe, which would theoretically eliminate this problem - at least in the vertical axis.

You can model a rigid without weight element from centerline to the outer surface of the pipe (with the pipe temperature) and to place the spring hanger there.

danb might be right but it depends on the ancillary on the pipe that attached to the spring.

Mechalex, I suggest you go through the catalog pages and select your spring type first and find out the ancillary required on the pipe. Some cases the spring attached members may take the load from centerline of the pipe. Some cases the pipe can sit on the saddle and the saddle is attached to the structural frame which spring is attached. You can find many variation of the supports with spring(s)

I suggest you select the spring and the support type first, perhaps this will give you the right answer, if not satisfied discuss with experts either here or with the supplier.