How can you export piping to IFC without the insulation attached to it?
When you export to IFC, all elements in the file get exported even if you have the level turned off. The only way to avoid including the piping insulation is to disable it by modifying any existing pipe in the model and setting the value for insulation to 0 so there is no insulation in the file just before you export to IFC. After you export it, you can include the insulation on the pipe in the model as it was originally.
Even if you map the insulation to a different IFC property, it is still considered part of the pipe so it will always get exported along with the pipe.