Breather for Conservator Tanks | Electrical Equipment Component

Product Specifications

Technical details and manufacturing context for Breather

Definition

A breather is a critical component of a conservator tank (expansion tank) in electrical equipment systems, particularly in power transformers. It maintains atmospheric pressure balance within the tank by allowing air to flow in and out during thermal expansion and contraction of the insulating oil, while simultaneously drying the incoming air and filtering out contaminants to protect the internal components. The breather typically contains a desiccant material (like silica gel) that absorbs moisture from air entering the conservator tank. As the transformer load and temperature change, the insulating oil volume fluctuates, causing the conservator tank's oil level to rise and fall. When the oil level drops, air is drawn into the tank through the breather, where it is dried. When the oil level rises, moist air is expelled from the tank through the breather. The breather is available in nominal diameters from DN50 to DN200 (ISO 6708) to match the conservator tank inlet size. It has an air flow capacity of 0.5 to 5 m³/h to handle oil expansion and contraction rates. Filtration efficiency is at least 99.5% for particles larger than 3 µm (ISO 16890). Moisture adsorption capacity is at least 200 g of silica gel desiccant, which should be replaced when saturated. Operating temperature ranges from -40°C to 85°C; outside this range, seal integrity may fail. Ingress protection is IP54 to IP65 (IEC 60529) to prevent water jets and dust ingress. The body is made of corrosion-resistant aluminum alloy AlSi12 (DIN EN 1706), and the desiccant is silica gel with cobalt chloride indicator (SiO2). Weight ranges from 5 to 20 kg depending on size and desiccant quantity. Always verify model-specific values and standards with the legal manufacturer or supplier.

Working Principle

The breather contains a desiccant material, typically silica gel, that absorbs moisture from air entering the conservator tank. As transformer load and temperature change, the insulating oil volume fluctuates, causing the oil level in the conservator tank to rise and fall. When the oil level drops, air is drawn into the tank through the breather, where it is dried. When the oil level rises, moist air is expelled from the tank through the breather. This process maintains pressure balance and protects the transformer from moisture and contaminants.

Common Materials

Aluminum alloy, Stainless steel, Silica gel desiccant

Technical Parameters

Parameter	Typical range	Notes & selection driver
Nominal Diameter	DN50–DN200 mm	Matches conservator tank inlet size.ISO 6708
Air Flow Capacity	0.5–5 m³/h	Must handle oil expansion/contraction rate.
Filtration Efficiency	≥99.5 %	For particles >3 µm.ISO 16890
Moisture Adsorption Capacity	≥200 g	Silica gel type; replace when saturated.
Operating Temperature	-40–85 °C	Outside range, seal integrity may fail.
Ingress Protection	IP54–IP65	Prevents water jets and dust ingress.IEC 60529
Body Material	AlSi12	Corrosion-resistant aluminum alloy.DIN EN 1706
Desiccant Material	SiO2	Silica gel with cobalt chloride indicator.
Weight	5–20 kg	Depends on size and desiccant quantity.

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

Desiccant chamber
Holds the moisture-absorbing material that dries incoming air

Material: Transparent polycarbonate or metal
Inlet/Outlet ports Part
Connects the breather to the conservator tank's air pipe

Material: Brass or stainless steel
Moisture indicator Part
Shows the saturation level of the desiccant (often color-changing silica gel)

Material: Glass or plastic window
Desiccant
The silica gel itself — it is what takes the moisture out of the air being drawn in.

Applied To / Applications

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

Conservator Tank (Expansion Tank)

View system integration details

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Frequently Asked Questions

What is the purpose of a breather in a conservator tank?

The breather allows air to enter and exit the conservator tank to maintain atmospheric pressure balance during thermal expansion and contraction of the insulating oil. It also dries the incoming air and filters out contaminants to protect the transformer's internal components.

How does the breather dry the air?

The breather contains a desiccant material, typically silica gel, which absorbs moisture from the air as it passes through. The desiccant must be replaced when saturated, as indicated by a color change if using an indicator type.

What are the key specifications to consider when selecting a breather?

Key specifications include nominal diameter (DN50–DN200), air flow capacity (0.5–5 m³/h), filtration efficiency (≥99.5% for >3 µm), moisture adsorption capacity (≥200 g), operating temperature (-40–85°C), ingress protection (IP54–IP65), and body material (AlSi12). Always verify these values with the manufacturer for your specific application.

How often should the desiccant be replaced?

The desiccant should be replaced when it becomes saturated, which is typically indicated by a color change if using silica gel with cobalt chloride indicator. The frequency depends on operating conditions and humidity levels. Regular inspection is recommended.

Data Basis

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

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pressure:	0 to 0.5 bar (g)
flow rate:	Up to 50 Nm³/h
temperature:	-40°C to +80°C
moisture removal:	Dew point -40°C

Breather

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