A large tubular plastic tank, for use in holding unpressurized water or wastewater, is formed by fusion welding together half-shell parts at lengthwise flange joints to form a tubular body. Then, end caps are fusion welded onto the outermost ends of the tubular body and an assembly of two or more bodies. Fusion weld elements are secured beforehand to the joining surfaces of the tank parts at a factory; the tank parts are then economically stored or shipped in nested condition to a fabrication site remote from the manufacturing site. Electric or electromagnetic energy is used to melt in situ the fusion weld elements which are captured between the joining surfaces of the parts.

A large tubular plastic tank, for use in holding unpressurized water or wastewater, is formed by fusion welding together half-shell parts at lengthwise flange joints to form a tubular body. Then, end caps are fusion welded onto the outermost ends of the tubular body and an assembly of two or more bodies. Fusion weld elements are secured beforehand to the joining surfaces of the tank parts at a factory; the tank parts are then economically stored or shipped in nested condition to a fabrication site remote from the manufacturing site. Electric or electromagnetic energy is used to melt in situ the fusion weld elements which are captured between the joining surfaces of the parts.

An integral side slope structure of a soil-covered tank, includes a tank body, connecting pieces, and reinforcing frameworks. The exterior of the tank body is completely covered with soil, and a side slope is formed after the tank body is covered with the soil; each connecting piece is composed of ribs which are in cross connection to each other; the connecting pieces are connected to the outer wall of the tank body and are laid inside the side slope in the horizontal direction; a single-layer connecting net is formed after a single layer of the connecting pieces is connected to the tank body; a plurality of layers of the connecting pieces are arranged at intervals in the vertical direction; the tank body and the side slope are connected by the multi-layer connecting net to form an integral structure; the reinforcing frameworks are arranged along the side slope.

Individual honeycomb shaped modules used in an assembly for underground storage of storm water and other fluid storage needs. Modules are assembled into a resultant honeycomb shape for maximized structural strength and material use efficiency. Internal hexagonal or square shaped modules are assembled and encased by external hexagonal or square shaped modules. Internal adjacent modules are in direct fluid communications with one another through a channel-less chamber. Internal hexagonal or square shaped modules drain into external hexagonal or square shaped modules chamber where fluid is either stored or drained. Assemblies include various top and side pieces along with access ports for entry into said assembly.

A system and method for monitoring liquid tanks that includes a submersible sensor within the tank below liquid surface. The system may also include a secondary sensor to determine ambient conditions, and a controller to determine when changes in liquid level are due to ambient events, or potential breach of system. A calibration rod may be used to monitor displacement of liquid in the tank and calibrate system to determine changes in height of liquid level.

The present invention relates to a storage tank, comprising a neck portion having an opening, the neck portion having side walls which define a first storage volume; a body portion connected to, and located below, the neck portion, the body portion having side walls and a base which define a second storage volume, wherein a section of the body portion is configured with a substantially rectangular cross-section in the horizontal plane, and wherein the second storage volume is greater than the first storage volume; and ribs projecting generally radially from the side walls of the neck portion and/or the body portion.

The present invention relates to a storage tank, comprising a neck portion having an opening, the neck portion having side walls which define a first storage volume; a body portion connected to, and located below, the neck portion, the body portion having side walls and a base which define a second storage volume, wherein a section of the body portion is configured with a substantially rectangular cross-section in the horizontal plane, and wherein the second storage volume is greater than the first storage volume; and ribs projecting generally radially from the side walls of the neck portion and/or the body portion.

An overlapping joint coupling system for septic chambers where the end of one chamber is designed to fit over the opposite end of an adjoining chamber of like construction, and where the overlapping end coupling section includes a retention pocket for receiving a flexible snap locking member formed in the underlying end coupling section, and the connection of the end coupling sections forms a joint which enables one chamber to pivot in a horizontal plane relative the other chamber of like construction.

An overlapping joint coupling system for septic chambers where the end of one chamber is designed to fit over the opposite end of an adjoining chamber of like construction, and where the overlapping end coupling section includes a retention pocket for receiving a flexible snap locking member formed in the underlying end coupling section, and the connection of the end coupling sections forms a joint which enables one chamber to pivot in a horizontal plane relative the other chamber of like construction.

A septic tank for storing and treating wastewater may be provided. In one implementation, a septic tank, having a first lengthwise end, an opposing second lengthwise end, a top, a bottom, a horizontal centerplane, and a vertical lengthwise centerplane, and a basic wall thickness T may be provided. The septic tank may include corrugated walls and an oblong flange lying nominally in the horizontal centerplane. The tank may further include opposing endwalls, each endwall integrally connecting an end of a first sidewall to an end of a second sidewall. The endwalls may include an endwall top, an endwall side running from the upper half tank flange to the endwall top along an inward slant, and the endwall side may along a curve which is a semicircle or a portion of a curve.