A welded water-tube boiler drum of SA-299-A material is constructed to an inside radius of 455 mm on the tubesheet and 480mm on the drum. The plate thickness on the tubesheet and drum are 45mm and 24mm respectively. The longitudinal joint efficiency is 100% and the ligament efficiencies are 54.5% horizontal and 30% circumferential. The operating temperature is not exceed 350 C. Determine the maximum allowable working pressure. Question 4 (4) Calculate the minimum required wall thickness of a superheater tube with 50 mm 0.D. that is strength welded. The tube in the convection area of the boiler and has an average wall temperature of 475 C. The maximum allowable working pressure is 4000 kPa gauge. The tube material is SA-335-P2.