1. A cast-iron pipe, 3 ft in diameter, is subjected to an internal gage pressure of 100 psi. Calculate the wall thickness required if the allowable tensile stress is 11,000 psi.
2. A steel pipe located in a hydroelectric power plant is 24 in. in diameter and has a wall thickness of 3 8 in. The system operates under a maximum head of 750 ft. Assuming an ultimate tensile strength of 55,000 psi, calculate the factor of safety for the pipe.