Here's my problem: I want to design a cylindrical combustion chamber for a hybrid propelent rocket. Basically, I will burn paraffin and use oxygen as oxidant. As I will be using stainless steel, I thought I could approximate the maximum stress that must be resisted by the material through a simple pressure vessel, so it would be t = σ/(p*r), where σ is the maximum stress resisted by stainless steel with a secutiry coefficient, p is the internal pressure and r is the internal radius and then I would have the needed wall thickness t. There is one problem, though: the combustion temperature is about 1000°C and I have no idea if it will affect greatly the resistence of the material. I believe, as paraffin is not a great heat conductor, there won't be much heat transference to steel and, as the combustion is quick (~10s), there won't be a great increase of temperature. Am I doing right?