Various shapes and configurations for tubular in-tank heat exchangers, or coils as they are generally known, are available. All of these can be varied to meet specific heat transfer requirements.

First, the smallest and simplest in-tank tubular heat exchanger is known as U-Coil. These coils are used for minimum heat-transfer requirements and are available in different lengths and widths to accommodate individual applications.

Serpentine coils are available for somewhat more demanding heat transfer requirements. They can be provided with as many loops as required, and in variable lengths. 

While the design of U-Coils and Serpentine coils is fairly straight forward, the design of grid coils provide a wide range of adjustability to ensure maximum heat transfer. Grid coils come in two basic styles-- vertical and horizontal.

Grid coils, as shown below, consist of two parallel manifolds--mostly  2" diameter tubing-- connected with a series of 1" diameter tubes. Inlet and outlet connections are provided with male pipe nipples to allow for ease of installation.

On horizontal and vertical grid coils, have variable length, width and number  of heat transfer tubes.

Standard U-Coil, depth and width are variable

Standard Serpentine Coil, length, width and number of loops are variable