ERT-F-W Extinguishing retention tank with widthways fixed beams


Tank with suffocating slats for electrical transformers

The ERT® F-W range comprises 12 standardised references of fireproof, self-supporting, fixed-beam, one-piece troughs in the width direction. SANERGRID®‘s ERT-FW range is designed to meet the regulatory, technical and environmental requirements of oil-filled electrical transformers from 160kVA to 20MVA.




The ERT-F-W range of bunds is part of SANERGRID®‘s ERT® family of transformer fire protection bunds and comprises a series of standardised bund references with integral dielectric containment and fixed beams (F) in the width direction (W), particularly where the centre-to-centre distance of the transformer is known.

Description of the ERT-F-W standard range :

  • S235 steel tank, thickness 3, 4 or 5 mm; hot-dip galvanising certificate to ISO EN1461-2022.
  • Double sealed welds on all parts of the retention zones to guarantee a completely watertight tank, with individual quality inspection before leaving the factory.
  • The upper part of each tank is fitted with an EXTICOV CCF fire extinguishing system consisting of single-slope fire dampers tested by CNPP.
  • A set of 2 support beams is fitted widthways (W) above each ERT-F-W tray, making it easy to place the equipment on the trays.
  • These are fixed (F) and are welded to the trays at centres that comply with the ECODESIGN.  All dimensions are available on the technical data sheet. On request before ordering, we can adapt to a special centre-to-centre distance if required.
  • The maximum allowable load (or MAL) for each tray is calculated and supplied for each tray with an additional safety coefficient to accommodate the transformer on its support beams.
  • At the foot of the bund, two watertight wall penetrations are available to accommodate 1.5-inch ¼-turn valves: the first valve to allow the bund to be drained, and the second to fit an SPI® PETRO PIT rainwater filtration kit. In the standard version, the bund is supplied with the two wall passages sealed with stainless steel plugs.
  • A safety siphon is always fitted to ERT-F drip trays. Fitted to the bottom of the drip tray, it allows overflowing water to be drained away without draining oil in the event of heavy rain or blockage of the filtration system.

ERT® F-W containers guarantee a service life in indoor and outdoor conditions similar to that of the electrical transformer or other machine they equip.

Accessories and options

The ERT® range comprises a range of monobloc bunds with different retention volumes, depending on whether they are used indoors or outdoors. Please contact us with your transformer dimensions.

Depending on the configuration of your project, the ERT® range is available in several versions:

  • Adjustable widthwise beams: ERT-W range 
  • Longitudinal beams: when entry to the substation is via the door or the site configuration requires it: ERT-L range (adjustable longitudinal beams) or ERT-F-L range (fixed longitudinal beams).
  • Addition of a grating for walking on the tray and accessing the transformer control unit, DGPT2 or auxiliary units: ERT-AUX range
  • ENEDIS ERDF configuration: Reinforced sizing + gratings for autotransformers (AT 5 MVA, 10 MVA, 15 MVA or 20 MVA), compensating impedances (IC 600 or IC1000), Peterso coils: ERT-AT range (adjustable beams widthwise + gratings) or ERT-F-AT range (fixed beams widthwise + gratings).
  • Non-carrying fireproof bund when embedded in a retention pit, under a substation or photovoltaic skid: ERT-NP range
  • Rolling bins to roll the bin directly with the transformer fixed on top, reusing the transformer’s wheels: ERT-R range (adjustable centre-to-centre beams) or ERT-F-R range (fixed centre-to-centre beams).
  • When the width of the bin exceeds the European transport gauge, modular tanks: ERT MODULO range in the case of larger transformers, the bins are placed side by side and linked together in 2, 3, 4, 5 or “N” modules connected together using the SNG-Flow™ system.
  • For skid-mounted photovoltaic applications to integrate the drip tray between the skid and the transformer: ERT-SKID range
  • Finally, for any customised design: you need the transformer to be rolled onto the trough, special support studs, a low-profile design, special geometry or design: consult our project managers with our ranges: ERT-SP range

The ERT-F-W range also comes with a number of accessories and options to suit your needs:

  • PETRO PIT kit, for use outdoors to allow continuous drainage of rainwater.
  • Lifting hooks.
  • SANERVIB anti-vibration pads.
  • Galvanic anti-corrosion treatment C5H GALVAGRID®.
  • Self-locking directional wheels: ROLL.
  • Inspection hatch.
  • Earthing, MALT.
  • SANERBLOCK™ transformer wheel locking stirrups.
  • Bodyguards : SANERFALL™
  • Access staircase : MODESCA™
  • Maintenance platform : PLATABUND™
  • Bracket for fixing and hanging on a photovoltaic skid or on the ground.
  • Rolling options: SANER-Rail, SANER-Grantex and Rippage (ranges for fixed beams only).

Technical data

Additional information



Conditions of use

indoor, outside

Type of bin



Fixed, Widthwise



Fire resistance


Use and maintenance

Before installing the tank:

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

Installing the tank:

The tray must be unloaded using suitable handling equipment. Once installed in the final position, fix the support beams, adjusting the centre-to-centre distance so that the transformer is centred on the supports of the ERT® tray.

Installation by crane :

Place the transformer on the beams of the trough, taking care not to obstruct the rainwater drainage holes. Avoid vertical acceleration or transverse shearing.

Installation by rolling or shifting :

In the event of handling by rolling the transformer onto the box or shifting the transformer from the lorry onto the box, 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 fire dampers: no overlaps or missing dampers, presence of CCF-STOP™, maintenance damper 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 rainwater is 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.
  • 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.

The owner of the equipment is responsible for and liable for any failure to comply with good usage practices and for any failure to deal with anomalies and defects in the field.

Additional information

Our tanks are in line with EU Regulation No 548/2014 also known as ECODESIGN on the implementation of Directive 2009/125/EC which sets out 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 retention tank complies with French, European and international standards and recommendations for the containment of dielectric fluids, fire risk management, the management of pollutants and rainwater 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, as well as soil 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 concerning the use of fireproof covers for transformer pits and tanks, as well as guidance on the pre-sizing of indoor and outdoor retention tanks and pits.
  • Our bunds 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 hydrocarbon pollution when used outdoors:

Thanks to the SPI anti-hydrocarbon water filter system, the tank is empty of water 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 COFRAC I.D. certified report: 003606/2776443/1/1/1 in 2015 (France), SPI Phoenix I.D. laboratory reports: AR67044 from 2002, 2004, 2005, 2009, 2018, 2022 (USA), TÜV report Nr 2432974 in 2016 (Germany), NUA -Z-11895-1/1-2016 report. (Non-exhaustive list)


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