18.5.3.1.1 Gravity and Pressure Loads. The longitudinal stresses in piping due to pressure and weight may be estimated using the following equation: where: = sum of the longitudinal stresses due to pressure and weight SL = internal design pressure, psig P = outside diameter of pipe, in. d = pipe wall thickness, in. t = resultant moment loading on cross section due to weight and other sustained loads, in-lb Mg = section modulus, in3 Z Vertical supports are spaced at 10-foot centers, so the moment due to gravity, may be conservatively Mg, estimated as follows: For a 4-inch-diameter pipe, where 16.4 plf: D = = 205 ft-lb = 2,460 in-lb = = 571 psi SL-DeadLoad = 949 psi For a 6-inch-diameter pipe, where 31.7 plf: D = = 396 ft-lb = 4,752 in-lb = 421 psi = 1,183 psi SL-Pressure By idealizing the piping runs as continuous beams, 18.5.3.1.2 Seismic Loads on Piping Runs A and C. the maximum bending moments and reactions can be readily estimated. Piping Runs A and C are 4-inch-diameter pipes, shown schematically in Figures 18.5-5 and 18.5-7. They are idealized as a two-span continuous beam. The design lateral load, is taken as: Fp,
18.5.3.1.1 Gravity and Pressure Loads. The longitudinal stresses in piping due to pressure and weight may be estimated using the following equation: where: SL = sum of the longitudinal stresses due to pressure and weight P = internal design pressure, psig d = outside diameter of pipe, in. t = pipe wall thickness, in. Mg = resultant moment loading on cross section due to weight and other sustained loads, in-lb Z = section modulus, in3 Vertical supports are spaced at 10-foot centers, so the moment due to gravity, Mg, may be conservatively estimated as follows: For a 4-inch-diameter pipe, where D = 16.4 plf: = 205 ft-lb = 2,460 in-lb SL-DeadLoad = = 571 psi = 949 psi For a 6-inch-diameter pipe, where D = 31.7 plf: = 396 ft-lb = 4,752 in-lb = 421 psi SL-Pressure = 1,183 psi 18.5.3.1.2 Seismic Loads on Piping Runs A and C. By idealizing the piping runs as continuous beams, the maximum bending moments and reactions can be readily estimated. Piping Runs A and C are 4-inch-diameter pipes, shown schematically in Figures 18.5-5 and 18.5-7. They are idealized as a two-span continuous beam. The design lateral load, Fp, is taken as: