introduCtion Defected Straight Pipe (continued) When concrete pipe is installed in a curved alignment by deflecting straight pipe, the point of curve, P.C., is at the midpoint of the last undeflected pipe section, and the point of tangent, P.T., is at the midpoint of the last deflected or pulled pipe. ConCrete pipe Beveled Pipe Beveled, mitered, or radius pipe incorporate a specific deflection angle into the joint to allow changes in direction of sewer lines without the installation of a manhole. The radius of curvature which may be obtained by beveled pipe is a function of the deflection angle per joint, diameter of the pipe, length of the pipe Maximum Deflection Angles Per 12.5 mm Joint Opening sections and wall thickness. Since the maximum permissible bevel for any pipe is dependent on the manufacturing process, the specification must be coordinated with the pipe manufacturer. Many manufacturers have standardized joint configurations and deflections for specific radii, and economies can be realized by utilizing standard sections. When concrete pipe is installed in a curved alignment using radius pipe, projections of the joints do not converge at a common point but are tangent to a common circle of diameter equal to the length of pipe sections. The point of curve is at the midpoint of the last straight pipe and the point of tangent is one half of the standard pipe length back from the straight end of the last radius pipe. The required number of radius pipe is equal to the length of the circular curve, L.C., in feet divided by the centerline length of the radius pipe, L minus 1/2 drop. Where possible, minor modifications in the radius are made so this quotient will be a whole number. Nominal Diameter (mm) 300 375 450 525 600 675 750 900 1050 1200 1350 1500 1650 1800 1950 2100 2400 2700 3000 12.5 mm Joint Opening Minimum Radius (m) 81 98 116 139 156 174 191 226 261 288 323 357 392 427 469 496 566 643 705 Deflection Angle per Joint (Degrees) 1.61 1.34 1.21 1.01 0.90 0.81 0.73 0.62 0.54 0.49 0.43 0.39 0.36 0.33 0.30 0.28 0.24 0.22 0.20 12.5 mm Joint Opening and 12.5 mm Bevel Minimum Radius (m) 87 96 113 130 144 162 179 196 214 234 249 284 321 353 Deflection Angle per Joint (Degrees) 1.61 1.46 1.24 1.07 0.97 0.87 0.78 0.71 0.66 0.60 0.56 0.49 0.44 0.40 stormwater treatment teChnologies box seCtions manhole and CatCh basin material LAFARGE PIPE eMANUAL PAGE 39