Here, I've given a demonstration of making:
3D to 2D Design ( Isometric to Orthographic ) and

2D to 3D Design ( Orthographic to Isometric ) { for checking accuracy  }

Firstly, I've had a 3D Design and I've to make "Mechanical 2D Detailed Drafting" from it.

The 3D Design of a Feed Check Valve I already have is given below:

Mechanical 2D Detailed Drafting made from the above 3D Design is given below:

But here's the real challenge. 

Will the drawing work properly? 

Isn't there any missing dimensions or anything?

To overcome this challenge, I did a extra work to ensure the Drafting Accuracy. And that is, I've re-designed the following Feed Check Valve from the "Mechanical 2D Detailed Drafting" I have made. And of course, compared the Original Design to the Remade Design to ensure the precision and accuracy.

The Re-Designed Feed Check Valve is shown below:

I APPRECIATE YOUR TIME WATCHING MY PROJECT.
You can contact with me for freelance work.