Filevault 2 VS Clean Erase of SSD

Hello.

I'm on a MacBook Air - 2014 model with OS X 10.10.3 installed and FileVault 2 activated.

In the coming days I would like to perform a clean install on my Mac's SSD! But, just a few days ago I decided to activate FileVault 2.

Will the clean erase process 'deactivate' FileVault 2?! Or will it continue activated?!

Also, if it continues activated, will it keep any files on the SSD?!

What I really want to do is completely erase the SSD!! I want to install only Yosemite (since I installed Yosemite over Mavericks).

Will I be required to reactivate FileVault 2 after the installation process?!

Thank you for any help you may provide me with.