Abstract: A leaching system (10) includes arched leaching chamber sections (12) and an angled adapter (18) connected adjacent chamber sections at a 22.5.degree. angle. The adapter includes a first portion (122) having sidewalls (140, 142) spanned by a vaulted portion (144) and a female end collar (126). A second end portion (124) has sidewalls (140, 142) spanned by a vaulted portion (144) and a male end collar (130). The first and second end portions are connected at an arched, vertical ridge (136). The adapter connects the leaching chamber sections in a nonlinear configuration to curve the leaching system to follow contours and avoid obstacles.

Abstract: A leaching chamber (10) includes first and second side walls (46) which have louver sections. The side walls are connected by vaulted portion (48) to define a chamber potion (12) terminating at a first end (16) and a second end (18). Male and female coupling collars (20, 30) are integrally connected with corrugation peaks at the first and second ends. An intermediate peak or structure (70) has a first portion (72) with a profile of the male coupling collar and a second portion (74) with a profile of the female coupling collar upon cutting between the two portions, two subchambers (12', 12") are formed each having a female coupling collar at one end and a male coupling collar at the other. An inlet end cap (14) is telescopically connected to the female coupling collar (30). The inlet end cap (14) has a sleeve (102) to receive a conduit carrying effluent and a diffuser (104) to diffuse the received effluent. The diffuser includes a sloping surface with diverging ribs (106).

Abstract: 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.

Abstract: A sleeve of plastic material from an extruder is molded by a blow molding apparatus into a tubular structure which includes two top walls longitudinally connected at base ends and apex ends. A splitting apparatus splits the longitudinally connected base ends apart to form two top walls. The top walls are oriented with their base ends upward. An extruder extrudes a flow of softened plastic which is divided by a manifold into four flows. Four applicators connected with the manifold apply beads of softened plastic along each top wall base end. A ribbed roller presses flexible strips against the plastic beads on each of the top walls. The flexible strips are fed from rolls of finite length mounted on a stand. The stand holds operating rolls and back up rolls. A splicing apparatus splices the trailing end of each operating roll with a leading end of the corresponding back up roll.

Abstract: An expandable core for handling and holding rolls of tubing. The core is comprised of support members connected to each other or a base extending along the longitudinal axis of the core by connecting links. The connecting links are pivotally attached at their terminal ends to the support members or the base rod to allow movement about a pivot assembly. Camming surfaces are mounted at the terminal ends of the support members and means for selectively expanding the core are adapted to engage the camming surface.