Chongqing Yuneng Oil-Filter Manufacturing Co.,Ltd, Beibei District, Chongqing (2026)

Name: Chongqing Yuneng Oil-Filter Manufacturing Co.,Ltd
Address: Beibei District, Chongqing, 400707, CN
Telephone: +86-23-63225705

Founded in 1995, 20 years experiences in R&D, manufacturing, and marketing of turn-key projects in oil purification, water and gas filtration, and other reclamation products. Pls feel free to contact us for discuss your oil filtration problem. Website: http://www.chinaoilpuriifer.com ; Email: [email protected] ; Hot line:86-23-63225705

29/05/2026

How to Choose the Right Dry Air Generator for Transformer Maintenance?
A dry air generator is used to supply clean, low-dew-point air during transformer installation, repair, and maintenance. Its main purpose is moisture removal from the internal space and protection of insulation materials from ambient humidity. In transformer maintenance work, the quality of the dry air directly affects drying efficiency and the final insulation condition.

Selecting the correct dry air generator is not only a matter of equipment capacity. It requires a clear review of dew point, flow rate, filtration quality, outlet pressure, site conditions, safety functions, and application type. This article explains the main technical criteria so engineers can choose a dry air generator that matches the actual maintenance task without over-specification or performance gaps.

dry air generator
Key Technical Specifications of Transformer Dry Air Generator
When choosing a dry air generator for transformer maintenance, there are specific important factors that need to be assessed due to their direct impact on the efficiency of the process and the reliability of operations.
1. Dew Point (The Absolute Priority)
Dew point defines the moisture content in the output air. Lower dew point means drier air.

A dew point of -40°C or lower is an essential requirement for transformer applications. In the case of ultra-high voltage transformers, even lower dew points up to -70°C may be required.

A low dew point ensures:

Effective moisture extraction from insulation
Prevention of condensation inside transformer tanks
Stable insulation performance

When comparing a dry air generator, dew point stability under continuous operation is more important than the minimum achievable value.
2. Flow Rate (Capacity)
Flow rate determines how quickly dry air can replace moist air inside the transformer.

The required flow rate depends on transformer volume. A simplified calculation approach is:

Small transformers: lower airflow requirement
Large power transformers: significantly higher airflow needed

A general guideline:

Air exchange rate should allow complete internal air replacement within a defined time frame

Insufficient flow rate leads to slow drying and inefficient maintenance. Oversized systems increase cost without proportional benefit. Therefore, matching flow rate to transformer size is essential when selecting a dry air generator.
3. Filtration and Purity
Air supplied into a transformer must be free from contaminants.

A standard dry air generator should include:

Particulate filtration (dust removal)
Oil mist filtration
High-efficiency air purification stages

Contaminated air can introduce particles and oil v***r into the transformer, affecting insulation quality. Filtration accuracy should typically reach 0.01 μm or better.
4. Outlet Pressure
Stable outlet pressure ensures consistent air delivery.

If pressure fluctuates:

Airflow becomes unstable
Drying efficiency decreases
Internal transformer conditions become unpredictable

A dry air generator should maintain constant pressure output with minimal variation. Adjustable pressure settings are recommended for different transformer types.

09/04/2026

SF6 Gas Refining Machine: Turning Waste Gas into a Strategic Asset
Recovered SF6 gas is rarely reusable without treatment. Decomposition products—such as SO₂, SOF₂, HF, moisture, and air contamination—accumulate over years of operation, especially in high-load HV and EHV systems.

A modern SF6 gas refining machine enables utilities to:

Restore degraded gas to ≥99.9% purity
Meet IEC 60480 regenerated gas standards
Eliminate the need for virgin SF6 procurement
Support circular economy objectives
Core Refining Technologies
Advanced SF6 gas refining machines integrate:

1. Multi-stage filtration:
Molecular sieves for moisture removal (dew point ≤ −40 °C)
Activated alumina and carbon for acidic by-products

2. Cryogenic liquefaction and separation: Efficient separation of SF6 from air, N₂, or CF₄

3. Precision purity control: Output gas purity ≥ 99.9% by weight

These features are vital, particularly for HV (52-145 kV) and EHV (greater than 145 kV) equipment, where the quality of gas has a direct impact on the machine's insulating materials and, hence, its long-term reliability.

Matching SF6 Treatment Strategies to Voltage Classes
1. Medium Voltage (≤24 kV) – Ban Effective 2026
Immediate transition to alternative gases in new equipment

Existing installations require:

Compact sf6 gas vacuum pump units
On-site or centralized SF6 gas treatment systems
High maintenance frequency makes fast recovery cycles essential

2. High Voltage (52–145 kV) – Ban Effective 2028
Large installed base remains operational well beyond 2030

Requires:

High-capacity vacuum pumping systems
Industrial-grade SF6 gas refining machines
Emphasis on gas purity to maintain insulation margins
3. Extra-High Voltage (>145 kV) – Ban Effective 2032
Long asset lifespans (40–50 years)
Extremely high gas volumes per compartment
Demands:
Multi-stage vacuum and recovery systems
Advanced refining to avoid costly gas replacement
Redundant monitoring and digital compliance records

24/03/2026

How SF6 Gas Treatment Supports Compliance Under the EU Ban After 2026
Sulfur hexafluoride (SF6) is a common choice for medium-, high-, and extra-high-voltage switchgear as the insulation and arc-quenching gas. However, with the number of global warming potential (GWP) values of around 24,300, SF6 is currently the focus of strict regulatory measures, especially the EU F-gas Regulation (EU) 2024/573.
The rule does not prohibit the use of SF6 in new electrical equipment immediately via a voltage-dependent phased banning system, unlike sudden bans. As a matter of fact, this measure, step by step, changes the way maintenance, refurbishment, and the management of asset life-cycle must be planned by utilities, EPC contractors, and equipment owners.

In this situation, SF6 gas purification, which is based on modern SF6 gas vacuum pumps and SF6 gas refining machines, is turned into an important compliance and sustainability strategy rather than a regular maintenance job.
Understanding the SF6 Ban: Voltage Levels and Effective Dates
Not all types of equipment are affected by the EU regulation in the same way. Rather, it is centred on low-voltage systems first and then spreading to higher voltage classes, which might require longer validation cycles for technical alternatives.
FAQ
Q1: How does investing in an SF6 gas refining machine reduce operating costs?
An SF6 gas refining machine is available that purifies and reuses contaminated or aged SF6 to ≥99.9% purity, thereby eliminating repeated purchases of virgin gas.
Refining can reduce the lifecycle gas costs by 40-70% for high- and extra-high-voltage equipment with large gas volumes. This will also be a way to adhere to the future restrictions on the use of virgin SF6.

Q2: What specifications should be prioritized when sourcing SF6 gas handling equipment?
Oil-free sf6 gas vacuum pump systems (to avoid gas contamination)
Refining systems compliant with IEC 60480
High recovery efficiency (≥99.9%)
Digital logging and audit-ready documentation

Q3: Why is oil-free vacuum technology recommended for SF6 recovery?
Oil-sealed pumps can introduce hydrocarbons into recovered SF6, making it unsuitable for reuse or refining.
The oil-free dry SF6 gas vacuum pumps play a role in eliminating subsequent pollution, also help in improving the gas quality and lessening the work of the following SF6 gas refining machines, which are mostly used in HV and EHV GIS systems.

Q4: When should recovered SF6 be refined instead of reused directly?
If the gas shows elevated moisture, acidic by-products, or air contamination—common in long-service or heavily loaded equipment—it must be processed through an SF6 gas refining machine.
Refining ensures dielectric strength is restored and prevents insulation failure after refilling.

28/01/2026

Best Practices for Transformer Oil Maintenance in Harsh Environmental Conditions
Transformers are critical components in power distribution networks, and their performance heavily relies on the condition of their insulating oil. Environmental conditions--such as extreme temperatures, moisture, dust, and chemical contaminants--can accelerate transformer oil degradation, leading to reduced efficiency and potentially equipment failure.
Maintaining transformer oil properly is critical to ensure its reliability and prolong its lifespan, so this article explores causes of oil degradation in extreme environments and provides best practices for keeping transformers running at their optimal level.

Impurities in transformer oil
Transformer Oil Degradation in Harsh Environments

Transformer oil is essential to insulation and cooling in transformers, yet harsh environments can quickly degrade its performance. Key factors contributing to oil breakdown include:

Oxidation - Long-term exposure to high temperatures and oxygen can form acidic compounds, which compromise efficiency, leading to the formation of sludge and waste products that compromise its efficiency and thus diminish effectiveness.
Moisture Ingress - Humidity and water contamination decrease dielectric strength while hastening corrosion.
Thermal Stress - High temperatures hasten chemical degradation while freezing temperatures may lead to oil thickening.
Contaminants - Dust, dirt, and chemical pollutants found in industrial or coastal environments can clog filters and diminish insulation properties, significantly decreasing insulation properties and making filtration systems inefficient.
Electrical Stress - Arcing and partial discharges produce harmful gases which deteriorate oil quality, creating electrical tension within a circuit and degrading its quality.

20/01/2026

How Double-Stage Vacuum Transformer Oil Filtration Works
A double-stage vacuum transformer oil filtration machine has two stages of vacuum. The first stage is usually a vacuum booster pump and the second stage is a rotary vane or similar backing pump. This design makes the vacuum level much deeper and more stable.

In double-stage systems, transformer oil undergoes enhanced atomization and extended exposure time inside the vacuum chambers. This allows not only free water but also deeply dissolved moisture and gases to be efficiently removed.

Key Characteristics of Double-Stage Systems:

Two-stage vacuum pump configuration
Higher and more stable vacuum levels
Superior degassing and dehydration performance
Suitable for high-voltage and critical applications

Double-stage vacuum transformer oil filtration machines are widely used in high-voltage substations, power plants, and transformer vacuum oil filling processes.

06/01/2026

Common Uses in Vacuum Processing of A Transformer
Vacuum pumping systems are crucial in starting up and maintaining a transformer.

1. Vacuum Drying (Moisture Removal)
There is a need in the process of vacuum drying, which comes from the hygroscopic nature of the solid insulation of the transformer. Even the smallest amounts of moisture in the insulation diminish the dielectric strength and speed its thermal degradation. The system starts the process by lowering the pressure, thus enabling moisture trapped in the cellulose to v***rise. This is the principle on which the transformer vacuum drying machine functions, where, under a vacuum, the boiling point of water drops to a lower level. This ultra-deep, low-temperature vacuum is the only process that does not thermally stress the insulation, thus resulting in the removal of deep-seated moisture.

2. Transformer Evacuation and Oil Injection
After the drying phase, the transformer has to be filled with insulating oil under vacuum conditions. This process is the work of the transformer evacuation system, which serves two purposes.

Removal of Gas: We have to ensure that there is no air and residual gases in the tank and windings. This is to ensure there is no partial discharge activity when the unit is activated.
Complete Impregnation: If an oil tank is maintained under high vacuum and oil is injected, the fibrous insulation is fully penetrated, and no air bubbles are trapped because of the high vacuum. It is very important to the EHV/UHV systems that pumps like the 150m3/h vacuum pump for power transformers can do vacuum drying and then, injection of oil directly to high voltage transformers, including 1000kV, for ultra high voltage systems.

3. Broader industrial applications
Deep vacuum generation principles extend the use of these systems to other high-precision industries, even beyond the power sector. The versatile transformer evacuation system is beneficial to vacuum smelting, chemical pharmacy, welding, and the production of electric vacuum devices, along with multiple other devices, showcasing its use beyond grid maintenance.

Conclusion: Elevate Your Grid Reliability with Yuneng
Much more than a simple pump, the vacuum pumping system is a sophisticated multifunctional device, which forms an integral part of the complex system of critical electrical infrastructure of utmost importance, ensuring operational integrity. These systems, with the help of advanced vacuum configurations like the ZJ Series with Roots Pumps, achieve and maintain ultra-deep vacuum levels, facilitate efficient vacuum drying, and ensure flawless oil impregnation. Improved grid reliability and reduced maintenance costs, coupled with extended transformer life, are what these systems promise.

If you are seeking to minimize transformer downtime, achieve unparalleled deep vacuum for your 1000kV apparatus, and ensure decades of reliable service, choose the proven efficiency of Yuneng’s specialized vacuum pumping systems.

Stop compromising on quality. Contact Yuneng today to request a quote, explore our ZJ Series units, and secure the definitive solution for your transformer evacuation and drying needs.

Address

Beibei District
Chongqing
400707

Telephone

+86-23-63225705

Website

http://www.yunengoilpurifier.com/

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