Acylindrical pressure vessel of an internal diameter of 1829mm is to have a design pressure of 0.86 mpa. the longitudinal weld will have a joint efficiency of 85%. a life of 30 years is desired when exposed to a corrosion rate of 0.125mm per annum. determine the nominal thickness of steel plate that must be ordered from the supplier given that the design tensile strength of the material is 115 mpa and there is a tolerance on nominal thickness of ±10%. the commercial thicknesses are in 0.5 mm increments. assume the only loads on the vessel are those due to pressure.

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.