Wall thickness (mm) = cylinder diameter (mm)X pressure (Mpa)\/(2X[Allowable stress]) For example, if you use 45 steel cylinder, then the allowable stress can be 200, and there is 2.5 times the safety factor.
The cylinder diameter is assumed to be 100mm, then the wall thickness is: 100X200\/(2X200)=50mm. The allowable stress of various materials is not very different, and the influence of the inner diameter of the cylinder is more.