Thanks Mr. Fletcher,
I'm waiting for a training about ASME B31.4, meanwhile I'm studying the code and I'm performing some "experiment" by Caesar.

As regards weight coating, I made two model of an existing subsea pipeline.

The first has a carbon steel jacket featuring elastic modulus, density, outside diameter and thickness of reinforced concrete; the jacket is anchored by Cnode to inner 40" carbon steel pipe every two meters.

I used carbon steel for the jacket because thermal expansion coefficients are almost identical for this material and reinforced concrete.

The second has carbon steel pipe only but featuring:

- Equivalent elastic modulus;
- Density and thickness of insulation the same as reinforced concrete.

Results (displacements, stress on parts of pipeline WITHOUT weight coating and loads on restraints) are quite different.

Best regards

Alessio