ERT-MODULO Modular extinguishing retention tank


Fire containment tank with suffocating slats for electrical transformers exceeding transport gauges

The ERT® MODULO range is made up of a number of made-to-measure fireproof retention tanks that can be assembled in modules. SANERGRID®‘s ERT-MODULO range enables you to meet all the regulatory and technical requirements for fire and hydrocarbon retention for your large high-voltage power transformers, without incurring increased transport costs.




The ERT-MODULO range makes it possible to create large areas and volumes for retaining the dielectric oils in your transformers thanks to an innovative and robust assembly in 2, 3, 4, 5 or “N” modules. Each module consists of a retention tank with single-slope suffocating slats from the ERT® range, which can be connected to the others using the SNG-Flow™ communicating vessel system for the passage of fluids between tanks.

The ERT-MODULO range is recommended for large transformers where the width of the container exceeds the European transport gauge (2500 mm). This makes it possible to create very large ERT-MODULOs to equip large electrical transformers of up to 300 T and more than 100 T of dielectric material.

The ERT-MODULO range is also used when on-site civil engineering is complicated or old, or when it is impossible to create a pit. The ERT-MODULO retention tank forms an “above ground” retention pit that replaces the traditional concrete pit, and rests on a flat, smooth, reinforced civil engineering concrete slab. This considerably reduces your structural work costs and the time it takes to bring your substations into compliance:

In just a few hours, you can use a simple concrete slab to create a retention area that complies with 4-in-1 regulations:

  • Retention: minimum 100% of the volume of the dielectric, sized by our design engineers
  • Extinguishing: hydrocarbon pool fires with the EXTICOV-CCF single-slope fire suffocating slats cover, which is fitted to all our range of tanks ERT®.
  • Filtration: thanks to SPI anti hydrocarbons filters for rainwater drainage with PETRO PIT 410 or PETRO PIPE PI616M2
  • Protection: of operators thanks to the systematic addition of an electro-forged 30×30 anti-slip grating, or an all-welded CUBE grating capable of withstanding 500daN/m² (2 operators + back-up can), but also SANERFALL™ technology guardrails or MODESCA™ stairs or PLATABUND™ access platform.

Other standard features of the ERT-MODULO range of fire-resistant retention tanks:

  • S235 steel tank, thickness 3, 4 or 5 mm; hot-dip galvanising certificate to ISO EN1461-2022.
  • Inter-tank cover caps with fastening clamp; bolts for fastening the tanks together and SNG-Flow™ watertight communicating vessel wall passages with seals, washers and installation keys
  • Double watertight welding on all parts of the retention tank area to ensure complete watertightness, with individual quality inspection before leaving the factory.
  • The upper part of each tank is fitted with an EXTICOV CCF extinguishing system consisting of CNPP-tested suffocating slats.
  • On top of each ERT-MODULO container, we design supports that allow the equipment to be easily placed on the containers. These can be fixed beams running the length or width of the modular enclosure, or adjustable beams, or beams fitted with rolling rails, or beams for shifting, or be made up of several elephant feet fitted with load distribution plates… depending on how you want to position the transformer on the enclosure: by craning, shifting or rolling.
  • At the foot of the bund, two watertight wall penetrations are available to accommodate 1.5 or 2 inch ¼-turn valves, depending on the format: the first valve for emptying the bund, the second for fitting an SPI rainwaters filtration kit. In the standard version, the bund is supplied with the two wall passages closed watertight with stainless steel plugs.
  • A safety siphon is always fitted to ERT-MODULO tanks. Fitted to the bottom of the tank, it allows overflowing water to be drained off without draining oil in the event of heavy rain or blockage of the filtration system.
  • Lifting hooks for easy unloading and on-site installation.

ERT® MODULO containers guarantee a service life in indoor and outdoor conditions similar to that of the electrical transformer or other machine they are fitted with.

Accessories and options

The ERT® MODULO range is 100% made-to-measure, depending on whether you use the enclosure indoors or outdoors. Please contact us with your transformer and/or transformer box dimensions.

This range also includes a number of accessories to suit your needs:

  • PETRO PIT kit or PETRO PIPE kit for outdoor use, to allow continuous drainage of rainwater.
  • SANERVIB-SP anti-vibration pads.
  • Galvanic anti-corrosion treatment C5H: GALVAGRID®.
  • Inspection hatch.
  • Earthing: MALT.
  • Wheel locking calipers: SANERBLOCK™.
  • Bodyguards SANERFALL™
  • Access staircase : MODESCA™
  • Maintenance platform : PLATABUND™
  • Bracket for fixing and anchoring to the ground.
  • Roll-on options: SANER-Rail, SANER-Grantex and Rippage (fixed beams range only).
  • Option of rolling the modular container with the transformer placed on top: ERT-MODULO-ROLL

Technical data

Additional information



Conditions of use

indoor, outside

Type of bin

fireproof, Modular


Adjustable, Fixed, Lengthwise, Widthwise



Use and maintenance

Before installing the tank:

  • Make sure that the ground surface is smooth, flat, clean and, above all, large enough to take the weight of the transformer and ERT® -MODULO tank.
  • Check that the positioning of the load pick-ups from the floor to the tray is appropriate, aligned and correctly dimensioned.
  • If the tanks are stored outside, they must be emptied regularly, and not handled with water inside.

Installing the tank:

The tank must be unloaded using suitable handling equipment.

Installation by crane :

Place the transformer on the supports provided. Avoid vertical acceleration or transverse shearing.

Installation by rolling or shifting :

In the event of handling by rolling the transformer onto the tank or shifting the transformer from the lorry onto the tank, please consult us beforehand or refer to the SANER-Rail, SANER-Grantex and Rippage options.


Regular visual inspection of the equipment should cover the following points:

  • Installation of suffocating slats: no overlaps or missing slats, presence of CCF-STOP™, maintenance slat lockout screw.
  • Tightness at wall penetrations, accessories and/or plugs correctly screwed in.
  • Integrity of the tank walls, no deformation or damage (knocks, impacts, rust, etc.).
  • State of ageing of the hot-dip galvanising protective layer and potential touch-ups.
  • Check that rainwaters are flowing properly through the filters: if they are clogged, clean the pre-filters, or change the filters if they are saturated or have exceeded their recommended service life.
  • Tightness and ageing condition of SNG-Flow™ communicating fluid system seals.
  • The frequency of these checks depends on the constraints of each site, depending on its degree of corrosion, dirtiness, presence of organic matter, etc.

Refer to the user manual for further details.

Failure to comply with good practice in use and failure to deal with anomalies and defects in the field are the responsibility of the owner of the equipment.

Additional information

As standard, all our series head designs are factory-tested by means of a so-called type test, which is accompanied by a complete quality file including the following elements:

  • Certificate of inspection of load-bearing welds and watertightness by penetrant testing of the ARDROX 996 p2 or PENTRIX 100 type or equivalent by a third-party organisation.
  • Certificate of inspection of critical dimensions after welding
  • Hot-dip galvanising certificate in accordance with standard EN-1179 and Galva thickness control certificate in accordance with standard EN-ISO-1461 issued by a third-party organisation.
  • Manufacturer’s certificate of material conformity and factory pre-assembly before shipment

On request, we can provide you with certificates, tests or specific calculation notes.

Our transformers are in line with EU Regulation No 548/2014 also known as ECODESIGN on the implementation of Directive 2009/125/EC, which lays down ecodesign requirements for the placing on the market or putting into service of transformers with a power rating of at least 1 kVA used in 50 Hz electricity transmission and distribution networks or for industrial applications. Called ECODESIGN Tiers 1 (2015) and ECODESIGN Tiers 2 (2021).

Our standard range of SANERGRID ERT-MODULO retention tanks complies with French, European and international standards and recommendations concerning the retention of dielectric fluids, fire risk management, the management of contaminants and rainwaters in high-voltage substations and the protection of people and property.

  • French standards NF C13-100 and NF C13-200 prevent electrical risks, overcurrents, earthing problems, fire risks, short circuits and lightning, soil pollution and environmental pollution.
  • Standard NF EN 61936-1, relating to the design and installation of electrical installations, which requires watertight retention representing 100% of the volume of oil used, and provides the necessary indications for pre-dimensioning retention volumes and surfaces, fire safety distances and systems, and rainwater management associated with the outdoor storage of hydrocarbons.
  • CIGRE 23-07 and IEEE 980 recommendations on the use of fire suffocating covers for transformer pits and tanks, as well as guidance on the pre-sizing of indoor and outdoor retention pits and tanks.
  • Our retention tanks are designed and manufactured in accordance with the European norms and standards of EUROCODE 3 (Calculation of steel structures).
  • Our manufacturing plants are certified ISO 9001 for their quality management process and IS0 14001 for their environmental management process, and are all based in Europe to encourage short supply chains and limit carbon emissions.
  • Our French and European sites enable us to guarantee that all our steel comes from European production, which is made up of over 50% recycled steel in order to limit the over-exploitation of resources and limit the carbon emissions linked to our manufacturing activities SANERGRID.
  • Rainwater drainage and oil pollution for outdoor use:

Thanks to the SPI anti hydrocarbons filter system, the tank is empty most of the time and ready to receive hydrocarbons. In compliance with the French Water Act (decree 77-254), the water discharged from the tanks is not contaminated with more than 5 ppm of hydrocarbons, in accordance with standard EN 858-1 (“light liquid separation installations”).
SPI® filters are regularly tested by independent laboratories: SANERGRID Bureau Veritas report certified COFRAC I.D.: 003606/2776443/1/1/1 in 2015 (France), SPI Phoenix laboratory reports I.D.: AR67044 in 2002, 2004, 2005, 2009, 2018, 2022 (USA), TÜV report Nr 2432974 in 2016 (Germany), NUA report -Z-11895-1/1-2016. (Non-exhaustive list)


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