A spherical pressure vessel 600 mm in diameter is made of cold-drawn steel having Su = 440 MPa, Sy = 370 MPa, and a thickness of 3 mm. The vessel is to withstand an infinite number of pressure fluctuations from 0 to pmax. a) What maximum pressure will cause static yielding? b) What maximum pressure will cause fatigue failure assuming that the joint and connections are adequately reinforced and do not cause weakening of the vessel.