MULTI-PURPOSE LID FOR SEPTIC TANK AND ASSOCIATED RISER
A kit, and an assembly formed with components of the kit, comprises a fitting for the top of a septic tank or water tank, one or more frusto-conical rings shaped to interconnect with an identical ring to form an undulating wall riser that extends upwardly from the tank top fitting, and a lid. The lid is shaped for multi-purpose use: closing off the opening of either the large end or the small end of a ring/riser—whichever is uppermost, or closing off the fitting when there is no riser. Joints between the rings of the riser, and between a ring/riser and the fitting of a tank, are held together by latching tabs and/or screws. A fitting may be integral with a tank top.
1 - 22 . (canceled)
23 . A lid configured for sealing a subsurface fluid tank, the lid comprising:
a top configured to cover an opening of the tank;
a circumscribing inner skirt extending downwardly from the top;
a circumscribing outer skirt extending downwardly from the top, wherein a diameter of the circumscribing outer skirt is larger than a diameter of the circumscribing inner skirt; and
a circumscribing middle skirt between the circumscribing inner skirt and the circumscribing outer skirt extending downwardly from the top, wherein the circumscribing middle skirt is configured to engage a gasket located in a fitting of the opening of the tank.
24 . The lid of claim 23 , wherein the top is flat.
25 . The lid of claim 23 , wherein the top is convex.
26 . The lid of claim 23 , wherein the lid forms a seal with the gasket located in the fitting of the opening of the tank.
27 . The lid of claim 23 , wherein the tank comprises a septic tank.
28 . The lid of claim 23 , wherein the opening of the tank comprises an opening in a riser connected to the tank.
29 . The lid of claim 23 , wherein the gasket comprises an O-ring.
30 . The lid of claim 23 , wherein the lid is made of thermoplastic.
31 . The lid of claim 23 , wherein the fitting of the opening of the tank comprises:
a flange having a rim defining an opening of the fitting;
a web having a top surface running radially inward from the flange to the rim;
a circumscribing first ridge on the web top surface in proximity to the rim; and
a circumscribing second ridge on the web top surface, wherein a diameter of the circumscribing second ridge is larger than a diameter of the circumscribing first ridge.
32 . The lid of claim 31 , wherein the circumscribing first ridge or the circumscribing second ridge comprises a gasket material.
33 . The lid of claim 31 , wherein the fitting further comprises a step where the flange meets the web.
34 . The lid of claim 31 , wherein the fitting further comprises a first skirt and a second skirt, wherein the first skirt and the second skirt extend downwardly from the web.
35 . The lid of claim 31 , wherein a height of the second ridge is larger than a height of the first ridge.