Transformer Tank - Sealed Enclosure for Power Transformers

Product Specifications

Technical details and manufacturing context for Tank

Definition

In a power transformer, the tank is the primary structural enclosure that contains all internal components including the magnetic core, high and low voltage windings, insulating oil, and cooling systems. It provides mechanical protection, contains the insulating medium, and serves as the foundation for mounting accessories like bushings, conservators, and radiators. The tank is typically fabricated from carbon steel or stainless steel, with wall thicknesses ranging from 4 to 12 mm, depending on pressure and mechanical requirements. Material grades commonly specified are Q235B to Q345R, with Q345R offering higher strength and corrosion resistance for demanding applications. The tank must withstand internal pressure variations caused by temperature changes and fault conditions, and it is designed to operate within a pressure range of 1.0 to 1.6 MPa. Leak rate is a critical parameter, with a maximum allowable leak rate of 0.1 mL/min to ensure seal integrity. The tank's dimensions and weight vary widely, from 1500×800×1200 mm and 500 kg for smaller units, up to 5000×2000×3000 mm and 20,000 kg for large power transformers. These dimensions and weight affect installation and foundation requirements. The tank is also rated for ingress protection (IP54 to IP65) to suit indoor or outdoor use, and corrosion resistance classes C3 to C5 per ISO 12944 are specified for different environmental conditions. Operating temperature range is -40°C to 85°C, which influences oil viscosity and material performance. The tank's design must comply with relevant standards such as IEC 60076 for transformers, GB/T 6451 for oil-immersed transformers, and GB/T 3274 for steel plates. When selecting a transformer tank, it is essential to verify model-specific values and standards with the legal manufacturer or supplier, as the parameters listed here are reference ranges for typical applications.

Working Principle

The tank functions as a pressure vessel that maintains the insulating oil in a sealed environment. It withstands internal pressure variations caused by temperature changes and fault conditions, prevents oil contamination from external elements, and facilitates heat dissipation through its surface and attached cooling equipment. The tank's design must ensure structural integrity under operating pressures and thermal expansion, while providing a leak-tight enclosure to preserve the insulating properties of the oil. Proper sealing and material selection are critical to prevent leaks and ensure long-term reliability.

Common Materials

Carbon Steel, Stainless Steel

Technical Parameters

Parameter	Typical range	Notes & selection driver
Rated Capacity	50–10000 kVA	Determines transformer size and costIEC 60076
Rated Voltage	10–220 kV	Higher voltage requires larger clearancesIEC 60076
Leak Rate	≤0.1 mL/min	Exceeds limit indicates seal failure
Wall Thickness	4–12 mm	Thicker for higher pressure ratingsGB/T 6451
Material Grade	Q235B–Q345R	Q345R for higher strength and corrosion resistanceGB/T 3274
Corrosion Resistance	C3–C5 ISO 12944	C5 for coastal or industrial environmentsISO 12944
Operating Temperature	-40–85 °C	Outside range may affect oil viscosityIEC 60076
Ingress Protection	IP54–IP65	IP65 for outdoor useIEC 60529
Weight	500–20000 kg	Affects installation and foundation
Dimensions (L×W×H)	1500×800×1200–5000×2000×3000 mm	Must fit transport and site constraints

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Components / BOM

Tank Body Part
Main structural shell providing containment

Material: Carbon Steel
Flanges Part
Connection points for accessories and covers

Material: Carbon Steel
Lifting Lugs Part
Attachment points for crane lifting during installation

Material: Carbon Steel
Drain Valve
Bottom outlet for oil drainage and sampling

Material: Brass or Stainless Steel
Tank Seals
Gaskets at every cover and flange joint; they are what makes the tank oil-tight.

Applied To / Applications

This component is essential for the following industrial systems and equipment:

Power Transformer

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Power Transformers

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Manufacturers of Tank

Manufacturer profiles associated with Tank.

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Compiled and source-reviewed by the CNFX editorial team. Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review · Page last updated 6 September 2026

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Frequently Asked Questions

What is the primary function of a transformer tank?

The transformer tank is the main structural enclosure that houses the core, windings, and insulating oil. It provides mechanical protection, contains the insulating medium, and supports accessories like bushings and radiators.

What materials are commonly used for transformer tanks?

Common materials include carbon steel and stainless steel. Material grades such as Q235B to Q345R are specified, with Q345R offering higher strength and corrosion resistance.

What are typical pressure and leak rate requirements?

Operating pressure is typically 1.0 to 1.6 MPa, and the maximum allowable leak rate is 0.1 mL/min to ensure seal integrity.

Why is it important to verify model-specific parameters?

Parameters like dimensions, weight, and material grades vary with transformer rating and application. Always confirm these values with the legal manufacturer or supplier to ensure proper fit and compliance.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records.

Preliminary Technical Classification

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pressure:	0 to 0.5 bar gauge (normal), 1.0 bar gauge (max test pressure)
other spec:	Dielectric strength >30 kV, moisture ingress <50 ppm, seismic zone 4 compliant
temperature:	-40°C to 105°C (operating), -50°C to 115°C (storage)

Tank

Product Specifications

Applied To / Applications

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