Move the mouse pointer to approximately r = 0.03 and z = 0.40 on the right side of the furnace.

Press and hold the middle mouse button.

Draw a horizontal line by moving the mouse to approximately r = 0.03 and z = 0.40 on the left side of the furnace.

Release the middle mouse button.

The new line splits the tube. At the intersections new points are created which split the crossed lines automatically.

Figure 24. Line intersecting the tube

Enlarge the intersected area by drawing a rectangle with the left mouse button.

You can see that the tube wall is a separate region, which was also intersected. We want only the interior of the tube to be split and no salient line segments.

Figure 25. Enlarged section of the cartridge

Select the right end point of the new line and the salient segment of the line with the right mouse button.

Click on the Delete button  .

Repeat steps 6 and 7 for the salient part of the line on the left.

Enlarge the section of the drawing as long as you can select the line segment inside the right region.

The drawing should look approximately like this:

Figure 26. Further enlarged section of the cartridge

Select the right end point of the line and the line intersecting the right region with the right mouse button.

Click on the Delete button  .

Click on the Zoom out button to reset the SCA to its original size.

The upper tube of the SCA has been intersected.

Figure 27. Intersected upper tube of SCA