Abstract: A coupling for multi-wall, corrugated pipe, the pipe including a corrugated wall having a plurality of primary corrugations, is disclosed. The coupling includes a first pipe section having disposed at one end a bell portion, the bell portion having a bell portion of corrugated wall and an outer wall; a second pipe section having disposed at one end a spigot portion, the spigot portion having a spigot portion of corrugated wall between an inner wall and an outer wall; and a gasket disposed in a groove extending around a circumference of the spigot portion and engaged between the bell portion of corrugated wall and the spigot portion of corrugated wall. A multi-wall, corrugated pipe section, and method for assembling a plurality of multi-wall, corrugated pipe sections, are also disclosed.

Abstract: A coupling for multi-wall, corrugated pipe, the pipe including a corrugated wall having a plurality of primary corrugations, is disclosed. The coupling includes a first pipe section having disposed at one end a bell portion, the bell portion having a portion of the corrugated wall and an outer wall; a second pipe section having disposed at one end a spigot portion, the spigot portion having a portion of the corrugated wall between an inner wall and an outer wall; and a gasket engaged between the corrugated wall of the bell portion and the outer wall of the spigot portion. A multi-wall, corrugated pipe section, and method for assembling a plurality of multi-wall, corrugated pipe sections, are also disclosed.

Abstract: A thermoplastic pipe gasket fabricated of a thermoset material is provided having a first pipe engaging surface and an exterior surface, with the exterior surface having applied thereto a water-based, flexible, slip-coating. The slip-coating comprises polyurethane, a cross-linking agent, and a dispersion of a friction reducing compound. The friction reducing compound can be selected from a fluoropolymer, silicone, or graphite, either alone or in combinations thereof. Depending on the method of fabrication, the slip-coating can be sprayed onto the thermoset material after the thermoset material has been extruded, but before the extrudate's fabrication into a gasket. Alternatively, the slip-coating can be sprayed onto the gasket following its assembly. Still further, the slip-coating can be applied to the thermoset material by dipping the thermoset material into the water-based, flexible, slip-coating.

Abstract: A coupling for three-wall, corrugated pipe, the pipe including a corrugated wall having a plurality of primary corrugations, is disclosed. The coupling includes a first pipe section having disposed at one end a bell portion, the bell portion having a portion of the corrugated wall and an outer wall; a second pipe section having disposed at one end a spigot portion, the spigot portion having a portion of the corrugated wall between an inner wall and an outer wall; and a gasket engaged between the corrugated wall of the bell portion and the outer wall of the spigot portion. A three-wall, corrugated pipe section, and method for assembling a plurality of three-wall, corrugated pipe sections, are also disclosed.

Abstract: A coupling for three-wall, corrugated pipe, the pipe including a corrugated wall having a plurality of primary corrugations, is disclosed. The coupling includes a first pipe section having disposed at one end a bell portion, the bell portion having a bell portion of corrugated wall and an outer wall; a second pipe section having disposed at one end a spigot portion, the spigot portion having a spigot portion of corrugated wall between an inner wall and an outer wall; and a gasket disposed in a groove extending around a circumference of the spigot portion and engaged between the bell portion of corrugated wall and the spigot portion of corrugated wall. A three-wall, corrugated pipe section, and method for assembling a plurality of three-wall, corrugated pipe sections, are also disclosed.

Abstract: An extrusion system is provided including an extruder, a screen changer, an operator interface, and a controller. The system further includes a pressure sensor for detecting an extrusion flow pressure between the extruder and the screen changer. A method of ramping up an extruder is also provided including the steps of detecting a pressure upstream from an extrusion screen filter; comparing the upstream pressure to a user-defined threshold pressure; and increasing an extrusion output if the upstream pressure exceeds the threshold pressure.