6. A pressure vessel having an internal diameter of 1000mm, constructed with a material tensile strength of 140 MPa at a design temperature of 140C, corrosion allowance of 0.70 mm and weld efficiency of 0.9. A spring loaded safety relief valve is used to protect overpressure with the following specifications, The design spring constant of 1500N/m, de 2r ra Valve orifice diameter of 10mm. Calculate Joo rooom a) The design pressure of the pressure vessel? b) The thickness and minimum shell thickness of the pressure vessel? Assume at the design pressure the spring compressed a length of 10 cm and neglect any friction losses. (5 pts