3D and 2D integration from the walls of a cylinder

Hello,

I need to get integral from the surface of a disk and the walls of a cylinder in 2D and 3D geometries.
I am fine with getting integral from the surface of a disk in 2D axisymmetric geometry and in 3D geometry and the obtaining results are exactly the same.
But it is not the case for the cylinder and I do have a big problem with it.
The way that I am getting integral from the surface of the geometries is:
Model>Definitions>Model Coupling> integration> Geometric entity level: boundary then I choses where it should be apply on the geometry.
For plotting:
In the case of disk, I use this expression in 2D: 2*pi*intop1 (r* necessary formula to solve for my model)
, and in 3D: intop1 (--------* necessary formula to solve for my model)
--------- means I do not using any expression for getting the integral of the surface of disk as COMSOL itself takes care of that automatically.
For the walls of the cylinder in 2D I use this expression: r*2*pi*intop1 (necessary formula to solve for my model).
And in 3D: intop1 (--------* necessary formula to solve for my model).
May please somebody tells me if these expression that I using to get integral from the surface of the walls of cylinder are correct or not please?

I do appreciate any replay to this question.

Thank you so much