Transformation of Simple to Double Wall Tanks


The procedure developed by Rafibra consists in the manufacturing of a double wall tank inside a old tank with permanent leak detection system, a simple tank being transformed into one double wall.

The double wall tanks,  with an annual or interstitial space between them, they are designed to prevent spills and therefore pollution of the subsoil. It’s installed a leak detection system that advises and emits a visible and/or audible signal front the entrance/exit  of fluid in the interstitial camera, constituting  a permanent control and protection system of the tank.

Cámara Intersticial

Cámara Intersticial

The double wall system can be installed in;

  • New buried metallic tanks or that have preserved  structural and sealing performance for storage of petroleum products.
  • Old tanks after performing the works of repair and conditioning according to the Norm UNE 53.991 and exposed in our procedure of repair and coating with reinforced plastics in metallic tanks for storage of petroleum products.

This application is especially suitable for tanks of steel sheet whose contents are gasoline and diesel; so the physical characteristics of the materials to be used, such as adhesion, elasticity, resistance to traction, compression, expansion and stability in time are the ideal for these fuels and additives

Depósito terminado

Depósito terminado


  • It gets transform the simple wall tanks into a double wall tanks which, together the installation of a permanent leak detection system, gets a real permanent detection system.
  • The system prevents the subsoil contamination or the hydrocarbon stored in case of existence of any leaks or defect in both walls, inside or outside.
  • The system is compatible with the entire range available leak detection system in the interstitial camera.
  • If the exterior wall of the tank it’s broken, would be a containment coating before reaching the interstitial camera.
  • The interstitial camera created is formed between the two walls of GRP preserving the passive protection inside of the metal of the outer wall of primitive tank.
  • In the case of perforation of the inner camera, may become to place a new wall, install the interstitial camera and put a new wall, whereupon it resets again the double containment system.
  • Both the first wall, the interstitial camera, as the second wall, form a monolithic single-stage system, since all the material is identical, resins and fiberglass complying with the Norme UNE 53.991 in terms of adhesion.
  • As monolithic do not occur efforts or tensions that it can cause detachment between layers and the first and second wall.
  • The system considerably increases the mechanical resistance since the tank is more strengthened by GRP walls of own steel tanks, unlike other systems that do not provide, nothing or very little increase in the mechanical strength of the shell and the walls among themselves are not united.


probeta 001

The set consists of an exterior tank and an inner enclosure consisting of a coating according to the norm UNE 53991, an interstitial Chamber with a 3D RAFIBRA-3D fabric and another covering according to the norm UNE 53991 in aspects relating to chemical resistance. The enclosure creates a space with the tank is tight and forming the detection Chamber.

This three-dimensional fabric RAFIBRA-3D camera ensures the continuous flow of fluid, for the detection of leaks.

This interstitial camera is installed a leak detection system through vacuum, pressure or fluid.


Hole, to connect the leak detection system, if it is going to be made by opening other than the above.

 sistema-doble-pared-003 sistema-doble-pared-004


Hole, to carry out the vacuum, or for filling of the detection camera, with the selected fluid.

To the tank it will be practiced two holes opening in the area of the mouth of man’s inner tank, from the interstitial camera, one for the entry or exit of fluid and the other for the air outlet (if applicable) with closing elements necessary to achieve the detection Chamber leakage.

Tanks transformation from single to double wall (RAFIBRA-RDP).

We use cookies to ensure that we give you the best experience on our website.