Hi all, I have started with my understanding of pressure vessels and i have some queries on the topic. 1) I understand the part of axial stresses.When a cylinder capped at both ends is subjected to internal pressure,it tends to increase the length of the shell,and therefore a resistance is offered by pressure vessel,which is measured by load (Internal pressure X circular area )/ the cross sectional area of Pressure vessel (One between I.D & O.D of the vessel) 2) To some extent,I understand the concept of hoop stress.The internal pressure inside the cylinder tries to displace the circumferential elements farther (Increasing the diameter of the cylinder).Therefore the hoop stress is measured by load (internal pressure X projected area )/ cross sectional area of pressure vessel (one which is the product of thickness and length considered) 3) My query now is,what is radial stress?.And what is the load for it and what is the area resisting it?.In what way it tries to deform the pressure vessel ?.And why do we neglect it for thin walled pressure vessels and consider it for thick walled pressure vessels ? 4) Also are both hoop and radial stress a response to diametrical deformation ? My understanding on this topic is elementary and I apologize if I have misstated something. Thanks for going through the post.