TRT-W Single welded retention tank with adjustable widthwise beams


Galvanised steel tank for electrical transformer

The TRT®-W range comprises 14 standardised, hot-dip galvanised, one-piece drip trays with welded fronts, fitted with width-adjustable support beams. SANERGRID®‘s TRT-W range is designed to meet the regulatory, technical and environmental requirements for indoor and outdoor live oil-filled transformers from 160 kVA to 20 MVA.




Description of the TRT-W standard range:

  • S235 steel tank, thickness 3 or 4 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.
  • At the bottom of each TRT® W trough, a set of 2 support beams is installed in the width direction. These adjustable beams make it easy to place the electrical transformer in the trough and keep it above the ground level of any residual water that may be present at the bottom of the trough when used outdoors. You can adjust the position of the TRT® beams on site to suit the centre-to-centre distance of your transformers.
  • At the foot of the bund, two watertight wall penetrations are provided by 316L steel/stainless steel inserts to accommodate 1.5″ diameter valves: the 1st valve to allow the bund to be emptied, and the 2nd 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 TRT-W drip trays. Fitted at the top of the drip tray, it enables overflowing water to be drained off without draining oil in the event of heavy rain or blockage of the filtration system. Threaded outlet supplied with plug: don’t forget to remove the plug if using outdoors.
  • Each TRT has 8 earthing points with lugs at each corner of the tray (lugs not supplied).

Its basic design, high degree of solidity, robustness and versatility of use have made the TRT® range a benchmark in the transformer containment market, whether for indoor or outdoor use, for short or long-term transformer storage, for use with live transformers, for new substations or substation renovation.

The TRT® W containers guarantee a service life in indoor and outdoor conditions similar to that of the electrical transformer or other machine they are fitted to, and offer a high degree of customisation (see Accessories and Options tab).

Accessories and options

The TRT®-W range comprises 14 standard monobloc drip trays, each with the required retention volume and matching the length and width of the transformer they are fitted to, depending on whether you are using the drip tray indoors or outdoors. Please contact us with your transformer dimensions.

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

  • Fixed beams where the transformer centre distance is known: TRT-P-F-W range (widthwise) and TRT-P-F-L range (lengthwise)
  • Addition of a grating to walk on the tray and access the transformer control unit, DGPT2 or RIS2 type protection relay or auxiliary units: TRT-AUX range
  • When you have rising vertical cable ducts on the HV and LV side: TRT-H range
  • When you have rising vertical cable ducts on the HV or LV side: TRT-U range
  • For skid-mounted photovoltaic applications to integrate the drip tray between the skid and the transformer: TRT-SKID range
  • In the case of larger transformers, when its width exceeds the standard European transport gauge of 2500 mm, several TRT trays are then placed side by side and linked together in 2, 3, 4, 5 or “N” modules connected together using the SNG-Flow™ system: TRT MODULO range
  • You can fit your TRTs with NFC-13200-compliant damper gratings: TRT-LHD range (monobloc) and TRT-LHD-MODULO range (modular with N connected modules).
  • For any bespoke application where you need to roll the transformer onto the pan, roll the pan with the transformer, or a special geometry or design: consult our project managers: TRT-SP range

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

  • PETRO PIT kit, an anti-hydrocarbon rainwater drainage filter for use outdoors to allow continuous drainage of rainwater.
  • SANERVIB anti-vibration pads to be fitted at the bottom of the tank to reduce transformer noise and vibration.
  • Galvanic anti-corrosion treatment C5H GALVAGRID®.
  • Earthing of gratings or MALT.
  • Wheel locking calipers SANERBLOCK™.
  • Lifting hooks.

Technical data

Additional information

Conditions of use

indoor, outside






Adjustable, Lengthwise, Widthwise

Fire resistance


Use and maintenance

Before installing the tank:

  • Make sure that the ground surface is smooth, flat, clean and, above all, large enough to support the weight of the transformer and the TRT® 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 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 TRT® trough.

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.


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

  • 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.

Please refer to the user manual for further details. Failure to follow good operating practices and to deal with anomalies and defects in the field are the responsibility of the owner of the equipment.

Additional information

Our bins 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 TRT tanks complies with French, European and international standards and recommendations on the retention 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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