Aspherical stainless-steel tank having a diameter of 26 in. is used to store propane gas at a pressure of 2075 psi. the properties of the steel are as follows: yield stress in tension, 140,000 psi; yield stress in shear, 65,000 psi; modulus of elasticity, 30 106 psi; and poisson's ratio, 0.28. the desired factor of safety with respect to yielding is 2.8. also, the normal strain must not exceed 1250 x 106.
(a) determine the minimum permissible thickness tmin of the tank.
(b) if the tank thickness is 0.30 in. and normal strain is measured at 990 106, what is the internal pressure in the tank at that point?