초록 ▼

A corrugated plastic side wall (A) extends from a bottom area (14) to an apex area (12). A riser (B) extends from the apex area above the ground level. A ring of steel channel (10) is fastened around the apex area to prevent the apex area from becoming distorted when the soil in which the tank is bu

A corrugated plastic side wall (A) extends from a bottom area (14) to an apex area (12). A riser (B) extends from the apex area above the ground level. A ring of steel channel (10) is fastened around the apex area to prevent the apex area from becoming distorted when the soil in which the tank is buried becomes water-laden. A tank bottom wall (122) is domed inward to inhibit exterior hydraulic pressure from flexing the bottom inward and from urging the corrugated side walls adjacent the bottom to compress to a smaller diameter in an accordion-like fashion. Downward projecting can (124) and boxes (126) extend from the domed bottom surface to a flat plane to prevent the dome from flexing outward under the weight of sewage and other fluids in the interior of the tank. At least one annular projection (52) extends around an outlet opening (44) to enable a tank wall portion (54) adjacent the outlet opening and outlet tubing (48) to move relative to the remainder of the tank.

대표청구항 ▼

In a corrugated sewage tank which has generally vertically extending alternating ribs and valleys which define a corrugated side wall extending between a bottom wall and an apex area and which ribs and valleys tend to compress in an accordion-like manner and which apex area tends to become distorted

In a corrugated sewage tank which has generally vertically extending alternating ribs and valleys which define a corrugated side wall extending between a bottom wall and an apex area and which ribs and valleys tend to compress in an accordion-like manner and which apex area tends to become distorted under large pressure differentials between the tank interior and exterior, the improvement comprising: an annular structure mounted to the tank and extending peripherally around the apex area for inhibiting the apex area from becoming distorted under exterior hydrostatic pressure when the tank is disposed in water-laden soil, the annular structure including a horizontally mounted portion to prevent horizontally inward compression of the apex area and a generally upward standing portion for preventing upward and downward deflection of portions of the apex area out of a plane defined by the annular structure.