DEPOSIT® subterranean containment pit for transformer

DEPOSIT® prefabricated subterranean containment pits allows you to install your interceptor faster, cheaper and more reliably in substations and for power transformers. Robust, reliable, resistant to corrosion and hot oils. Twice safer than concrete pits thanks to their double wall and watertightness controled by pressure sensor.

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How :


Oil has a lower density than water which allows it to float on the surface. The DEPOSIT® range has been specially designed to answer the 5 problems of a buried remote pit for oil-filled power transformers by using this principle of fluid separation:

- Total retention of the dielectric oil,
- Water and oil tightness,
- Decantation and separation of water and oil
- Evacuation of rain water and fire water (firemen, sprinklers, flood) in case of emergency
- And resistance to hot transformer oils.


Characteristics common to the standard DEPOSIT® technology:


The DEPOSIT® range consists of several prefabricated pits with different retention volumes. They are made of reinforced fiberglass and have a double wall.

This double wall is constantly pressurized and monitored by a pressure gauge which allows the detection of a possible leak or a loss of tightness. In case of a rupture of one of the walls, the pressure drop between the two thicknesses allows to identify the problem from the surface.

In addition to retention volumes, the DEPOSIT® range developed by SANERGRID® is available in several prefabricated offset pit standards:

- Single-chamber remote tank (Mono Volume): DEPOSIT®-MV range,
- Single-chamber remote tank for the storage of emergency fire water (Deluge Water): DEPOSIT®-DW range,
- Triple volume tank: DEPOSIT®-TV range.

DEPOSIT® pits are connected to the network either by nozzles (concrete, steel-cement, ...), flanges or sleeves. Other types of connections can be studied according to your needs.

The size of these connections and their diameter can be adapted on request to allow you to treat any water flow.

All our pits are designed according to the standards of the trade and manufactured according to an ISO 9001 process to guarantee a high level of reliability and quality.

Construction standards :

- NF EN-13121 : GRP tanks and containers for above ground applications - Part 3 : design and manufacture
- NF-EN 976-1 : Underground glass reinforced plastic (GRP) tanks - Horizontal cylindrical tanks for the non-pressurized storage of liquid petroleum fuels - Part 1 : requirements and test methods for single-walled tanks.
- NI 50-20-04(4-0): Glass-reinforced composite buried emergency receivers. This standard establishes a technical reference imposed by IBERDROLA for the minimum technical characteristics and tests to be carried out on emergency receivers of the DEPOSIT® range.

Test standards:

In addition to having been designed according to the standards stated above, our DEPOSIT® pits have been tested by an independent laboratory (AIMPLAS) to verify:

- The chemical resistance of the walls in accordance with NF-EN 976-1:

The high chemical resistance of our pits with the dielectric is ensured by the application of a vinyl-ester Epoxy resin on the internal walls. This guarantees the longevity and the watertightness of the pit during the whole life of the product (40 years);

- Flexural properties in accordance with NF-EN ISO 14125:

The mechanical resistance of all the elements of the pit is also reinforced by the application of an Iso-phtalic resin. A DEPOSIT® pit installed and anchored according to the manufacturer's recommendations can thus support surface loads.

- The temperature of thermal deflection in accordance with UNE-EN ISO 75-30:

DEPOSIT® retained its physical, mechanical and waterproof characteristics after 2 successive recoveries of the maximum expected volume for 24 hours with oil at 150°C.

At the end of the manufacturing process of our products, the tightness is tested in the factory by applying a negative pressure in the double wall of each DEPOSIT® pit in order to create a vacuum and measure the possible leakage: this air test method is much more reliable than a water test.
Installation principle (for more details and recommendations, see FUSE DEPOSIT):

- Dig an excavation in the ground large enough to accommodate the pit,
- Pour a flat concrete slab to accommodate the pit,
- Grout the DEPOSIT® pit in the excavation, weight it down or anchor it,
- Fill the excavation with gravel in successive layers to the surface.

General product maintenance:

DEPOSIT® pits require simple maintenance and inspection operations, recommended by the manufacturer:

- After each stormy episode or intense rain or flooding of the transformer (extinguishing system), check that there are no obstacles obstructing the various pipes.
- Every 3 months, check with the manometer that there are no leaks or problems with the tightness of the double wall.
- Every 5 years, check that the tank is in good condition by a visual inspection inside the tank.

In case of leakage, deterioration or any other repair to be done, contact us to define the best way to proceed...

End of life, recycling or destruction of the product :

The pit must be entrusted to an approved waste manager. On additional estimate, we can through the manufacturer propose you the scrapping and the destruction of the material.

Standard manufacturer's warranty: 24 months from delivery
To download the documentation, clic on the following image:

brochure DEPOSIT SANERGRID miniature

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