QTHS-3-250

SF₆ Gas Vacuum Pumping Service Unit

The YUNENG SF₆ Gas Vacuum Pumping Service Unit is a specialized high-performance equipment designed for vacuuming and initial evacuation of SF6 gas-insulated electrical equipment (such as GIS, circuit breakers, and transformers).

As SF₆gas requires an extremely dry and clean environment to maintain its insulation properties, our unit ensures that all air and moisture are efficiently removed from the gas chambers before refilling. This series combines a high-speed roots pump with a reliable rotary vane vacuum pump, achieving rapid evacuation to the required vacuum level, ensuring the long-term stable operation of high-voltage power systems.

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SPECIFICATION
ADVANTAGE
APPLICATION
GALLERY

The performance of an SF₆ vacuum pumping unit is defined by its ultimate vacuum degree and pumping speed. YUNENG’s systems are engineered with a high-efficiency dual-stage vacuum architecture, integrating a premium rotary vane pump with a powerful Roots blower. This configuration enables rapid evacuation to the required vacuum level (down to ≤1 Pa), effectively removing moisture and non-condensable gases from GIS chambers and associated gas systems.

The following technical parameters apply to the model with a 250 m³/h pumping capacity, designed for efficient evacuation of medium to large SF₆ gas compartments during installation and maintenance operations.

YUNENG also provides units with other pumping capacities, such as 500 m³/h, 1000 m³/h, and larger or smaller configurations, which can be customized according to specific project requirements.

Item	Name of Parameter	Unit	QTHS-3-250
Technical parameters	Type	/	Mobile
	Working temperature	℃	-20℃～50℃
	Ultimate vacuum of vacuum pump unit	Pa	≤1
	Pumping rate	M³/H	≥250
	Measuring range of vacuum gauge	Pa	0-100000 (Absolute pressure)
	The vacuuming time to 1mbar for a container with a volume of 1m³ and an initial pressure of 1bar	mins	≤13
	The vacuuming time to 0.2mbar for a container with a volume of 1m³ and an initial pressure of 1bar	mins	≤46
	Number of evacuation interface groups	/	1
	Size of evacuation interface	DN	20
	Working power	/	As per buyer’s option
	Dimension for reference	mm	13008501350
	Total power	kW	≤4
	Weight for reference	Kgs	260
*Due to different equipment configurations, its dimensions, weight and gas treatment indexes will vary slightly.

1. Advanced Design with Complete Functions

The 250 m³/h SF₆ Gas Vacuum Pumping Unit features an advanced and integrated design with optimized structure and user-friendly operation. The system layout ensures reliable performance while keeping operation simple and intuitive for field engineers.

2. High-Performance Rotary Vane Vacuum Pump

The vacuum pump adopts a double-stage rotary vane structure, providing stable vacuum performance and high pumping efficiency. An automatic anti oil-backflow device is integrated to prevent oil return during shutdown, ensuring clean and safe operation.

3. Roots Booster Pump for Improved Pumping Efficiency

Combined with a Roots booster pump, the unit significantly enhances pumping speed in medium and low vacuum ranges, reducing evacuation time for SF₆ insulated equipment.

4. Automatic Phase Protection Electrical System

The electrical system automatically detects three-phase power sequence and provides automatic phase-loss protection, ensuring safe startup and preventing motor damage under abnormal power conditions.

5. SF₆ Dedicated Valve Control System

The control system adopts specially designed SF₆ service valves, improving sealing performance and operational reliability during vacuum pumping processes.

6. Mobile and Field-Oriented Design

The equipment is designed as a mobile trolley type, allowing easy transportation and convenient operation in substations and onsite maintenance environments.

This unit is indispensable for the installation and maintenance of: