I came across a situation today that I've never encountered before. When making a detail drawing of a basic valve, the one part is a perfect sphere, with no holes grooves just a perfectly smooth sphere, and I was unsure how to dimension it properly. My concern is that in 2D a perfect sphere looks the same from every direction and the manufacturer might be a little confused seeing the exact same view two or three times. A couple quick searches provided no clear answer so I simply showed one view calling out the diameter and added a note saying "This part is a perfect sphere."
Is there a more proper way to do this, with maybe some sort of annotation or symbol to denote sphere-ism?