I want remove model's center line after expert Naviswork NWC File

I want remove model’s center line after expert Naviswork NWC Files.

Because, I Experted NWC Files. I Saw Any Pipe Models Center line.

I want Remove This Center line Model and Expert NWC Files.

Who Knows This ?

My Revit And Navisworks Version is 2017.

Just a hunch: Try turning off the sub-category before you export.