Flue angles

[brickie in oz]

Re: Flue angles

I understand that many codes limit flue angles to 30 degrees;

Flue or gather?
A flue works best if its straight with no bends.

[regbell]

I understand that many codes limit flue angles to 30 degrees; but some of the photos of pizza ovens show flues at greater than that. Regulations aside, what is known about the physics of flue angles on the forgo bravo ovens?