We "double dipped" here, and used the same input fields for two different things - insulation and refractory. You can't incorporate both in the same model using these input fields. You can model one, the other must be accounted for using uniform loads.

If your pipe is a gas line (like steam, where the fluid density is negligable), then it makes no difference which one you model and which one you incorporate as a uniform load. However, if you have a fluid line, I would model the refractory and use the uniform load option to include the insulation. The reason for this is so that CAESAR II can properly determine the fluid weight in the reduced inner volume of the pipe.

Since you're using a uniform load vector (say U1) to model system weight, make sure that every place you have "W" in your load cases, you also have "U1". Also note that you can't run dynamics with this model, since the uniform loads won't transfer as part of the system mass.