Abstract: A webless corrugated dual wall foundation drain which is constructed as a hollow rectangular tubular member with an inner corrugated wall formed of HDPE and an integral outer smooth wall formed of the same material. The outer smooth wall of the foundation drain is attached to and integrally formed with the corrugations of the inner corrugated wall through a coextrusion process, thereby significantly enhancing the vertical beam stiffness of the foundation drain and eliminating the need for an internal supporting web.

Abstract: A method of rotationally molding a large-diameter pipe fitting, the wall structure of which is characterized as having a generally smooth interior surface and an exterior surface that is defined by a plurality of axially-spaced circumferentially extending ribs which are monolithically formed and homogeneous with the smooth interior surface of the fitting. The fitting is seamless and modularly designed with integral coupling elements at each terminal end, and with a ribbed wall structure profile capable of withstanding the loads typically found in buried applications with watertight performance requirements, where such ribbed wall structure meets the following dimensions and dimensional ratios: Rib Sidewall Angle (95-105 degrees); Bottom/Top Rib Thickness Ratio (1.80-2.80); Pitch/Rib Height Ratio (1.50-1.95); Rib Height/Fitting Diameter Ratio (0.04-0.09); and Avg. Rib Thickness/Rib Height Ratio (0.28-0.40).

Abstract: An inspection system and method for scanning and recording defects in the surface of the smooth inner wall of dual wall corrugated plastic pipe during manufacture utilizing automated laser technology, in order to minimize potential disruptions in the manufacturing extrusion process and alleviate concerns as to improper formation of the inner wall. The inspection system includes conical laser pattern generator that passes through the dual wall corrugated pipe during the manufacturing process to complete 360 degree scan coverage of the surface of the inner smooth wall of the pipe. The inspection system further includes a set of cameras properly aligned to record comprehensive three dimensional coverage of the scanned image of the inner wall of the dual wall corrugated pipe. This inspection system and method has particular benefits in the manufacture of coilable dual wall corrugated plastic pipe, where the material make-up of the polymer melt used for the inner wall has been altered.

Abstract: A webless corrugated dual wall foundation drain which is constructed as a hollow rectangular tubular member with an inner corrugated wall formed of HDPE and an integral outer smooth wall formed of the same material. The outer smooth wall of the foundation drain is attached to and integrally formed with the corrugations of the inner corrugated wall through a coextrusion process, thereby significantly enhancing the vertical beam stiffness of the foundation drain and eliminating the need for an internal supporting web.

Abstract: High flow capacity corrugated coilable dual wall plastic pipe having improved longitudinal flexibility and a bend radius sufficient to permit coiling and plowing of such pipe into the ground using automated installation equipment. The coilable dual wall pipe has an outer corrugated wall formed of a thermoplastic material such as high density polyethylene, and an inner smooth wall formed of a different more flexible and resilient thermo-bondable material that has an enhanced strain capacity and lower modulus of elasticity. The inner wall material also has enhanced mechanical properties which generally improve processing and help prevent excessive drag and tearing of the liner material during the manufacturing process.

Abstract: An inspection system and method for scanning and recording defects in the surface of the smooth inner wall of dual wall corrugated plastic pipe during manufacture utilizing automated laser technology, in order to minimize potential disruptions in the manufacturing extrusion process and alleviate concerns as to improper formation of the inner wall. The inspection system includes conical laser pattern generator that passes through the dual wall corrugated pipe during the manufacturing process to complete 360 degree scan coverage of the surface of the inner smooth wall of the pipe. The inspection system further includes a set of cameras properly aligned to record comprehensive three dimensional coverage of the scanned image of the inner wall of the dual wall corrugated pipe. This inspection system and method has particular benefits in the manufacture of coilable dual wall corrugated plastic pipe, where the material make-up of the polymer melt used for the inner wall has been altered.

Abstract: High flow capacity corrugated coilable dual wall plastic pipe having improved longitudinal flexibility and a bend radius sufficient to permit coiling and plowing of such pipe into the ground using automated installation equipment. The coilable dual wall pipe has an outer corrugated wall formed of a thermoplastic material such as high density polyethylene, and an inner smooth wall formed of a different more flexible and resilient thermo-bondable material that has an enhanced strain capacity and lower modulus of elasticity. The inner wall material also has enhanced mechanical properties which generally improve processing and help prevent excessive drag and tearing of the liner material during the manufacturing process.

Abstract: A method of rotationally molding a large-diameter pipe fitting, the wall structure of which is characterized as having a generally smooth interior surface and an exterior surface that is defined by a plurality of axially-spaced circumferentially extending ribs which are monolithically formed and homogeneous with the smooth interior surface of the fitting. The fitting is seamless and modularly designed with integral coupling elements at each terminal end, and with a ribbed wall structure profile capable of withstanding the loads typically found in buried applications with watertight performance requirements, where such ribbed wall structure meets the following dimensions and dimensional ratios: Rib Sidewall Angle (95-105 degrees); Bottom/Top Rib Thickness Ratio (1.80-2.80); Pitch/Rib Height Ratio (1.50-1.95); Rib Height/Fitting Diameter Ratio (0.04-0.09); and Avg. Rib Thickness/Rib Height Ratio (0.28-0.40).