High strength multiple passageway plastic conduit

A corrosion resistant conduit means adapted for being buried underground and the like without crushing comprising:

• a. a plurality of interior walls defining a plurality of at least seven longitudinally extending adjacent passageways;
• at lease one of said passageways being an interior passageway that is completely surrounded by exterior passageways such that all of its walls are precluded from having external cooling by a media exteriorly of said conduit means;
• said interior walls comprising an extrudable plastic that is substantially uniform in cross sectional texture and density, that is free of any interface and imperfections formed by joining exterior walls, and that is free of an intolerable thermal sag due to sagging of the pliable plastic before it can be cooled;
• b. an exterior wall covering said longitudinally extending passageways and integrally formed with the outermost ends of said interior walls;
• said exterior wall comprising an extrudable plastic and subject to being crushed inwardly by the weight of dirt thereover when not reinforced by ribs and buried in the earth;
• and
• c. a plurality of longitudinally extending ribs integrally formed with said exterior wall;
• said ribs being external ribs that are disposed exteriorly of said exterior wall;
• said plurality of ribs reinforcing said exterior wall and increasing the flexural strength of said conduit and the exterior pressure resistance of said conduit such that longer sections of said conduit can be carried and installed for economy of installation;
• and such that corrosion resistance and large load carrying capability and soil resistance allow said conduit means to be employed in subterranean locations that would otherwise corrode metallic conduit and the like.