THIN-WALLED PRESSURE VESSELS: - A tank or pipe carrying a fluid or gas under a pressure is subjected to tensile forces, which resists bursting, develops across longitudinal and transverse directions. SPHERICAL SHELLS: Illustrative Problem: A cylindrical steel pressure vessel 400 mm in diameter with a wall thickness 0f 20 mm is subjected to an internal pressure of 4.5 MPa. Determine; a) the tangential stress in the steel b) the longitudinal stress in the steel c) to what value may the internal pressure be increased if the stress in the steel is limited to 120 MPa Solution: Solution cont’d: Solution cont’d: Illustrative Problem: Solution: Solution cont’d: Illustrative Problem: Solution: Problem Set No.01: A water tank is 8 meters in diameter and 12 meters high. If the tank is to be completely filled, determine the minimum thickness of the tank plating if the stress is limited to 40 MPa. Problem Set No.02: A pipe carrying steam at 3.5 MPa has an outside diameter of 450-mm and a wall thickness of 10-mm. A gasket is inserted between the flange at one end of the pipe and a flat plate used to cap the end. How many 40-mm diameter bolts must be used to hold the cap on if the allowable stress in the bolts is 80 MPa of which 55 MPa is the initial stress. What circumferential stress is developed in the pipe? Problem Set No.03: A spiral riveted pen stack 1.5-m in diameter is made of steel plate 10-mm thick. The pitch of the spiral or helix is 3-m. The spiral seam is a single riveted lap joint consisting of 20-mm diameter rivets. Using a shear stress of 70 MPa and bearing stress of 140 MPa, determine the spacing of the rivets along the seam for a water pressure of 1.25 MPa. Neglecting the end thrust, what is the circumferential stress. Problem Set No.04: The undersea research vehicle Alvin has a spherical pressure hull 1 m radius and shell thickness of 30 mm. The pressure hull is steel having a yield point of 700 MPa. Determine the depth of submergence that would set up the yield-point stress in the spherical shell. Consider sea water to have specific weight of 10.27 kN per cubic meter