SF6 gas recovery unit

At Amperis, we are committed to providing our clients with all sorts of instrumentation and testing solutions. Ranging from high voltage testing equipments to gas recovery units, our instruments are reliable, easy to use and most importantly, safe to operate.
These SF6 gas recovery units from AGRU-8 series are easy to operate, trustworthy and efficient.

More about SF6 Gas recovery units from AGRU-8 series:
SF6 gas is a great electrical insulator. Employing SF6 gas in switchgears is found to be a more effective method than relying on air or vacuum for dielectric functions. SF6 gas not only provides insulation, it provides the kind of stable operation at routine pressure levels that vacuum cannot provide.
That being said, SF6 gas has a high degree of greenhouse effect associated with it. Hence, simply releasing this gas into atmosphere is not only utterly unprofessional but also very dangerous for our planet. That’s where the SF6 gas recovery units from the AGRU-8 series come in. These units are extremely effective in utilising the negative pressure (partially or wholly) provided by gas absence in switchgears to extract and store traces of SF6 gas in the provided storage tanks. Thus, you can ensure that you maintain an efficient and environment-friendly operation while saving SF6 gas for future usage after purification.
The operation of AGRU-8 series units is very simple and convenient. The operation consists of a simple 2-valve system that can be used to recover up to 99.99% of SF6 gas in one cycle.
The operation schematic is given below:

  • Suction and Compression: The AGRU-8 series gas recovery units use sophisticated and durable suction and compression machinery that allows for powerful suction and further compression of SF6 gas.
  • Purification: Molecular sieves are employed in these units to purify the compressed SF6 gas for further processing. Impurities as small as 0.1 microns in diameter can be filtered out.
  • Liquefaction: Further compression and condensation assembly liquefies the compressed SF6 gas for easy storage and discharge.

The important technical specifications of AGRU-8 units are given below:

Physical specifications

58" (1470 mm) Wide x 45" (1140 mm) Deep x 74" (1900 mm) // 950 lbs. (432 kgs.)

Input power

110Vac/60Hz - 220Vac/50Hz - other available configuration

SF6 Compressor

Three (3) High Pressure Single Stage Direct Drive Oil-less Compressors capable of producing pressures of 70 bar. Compressor motor 1/2 kW, 3450 rpm. Compressor has metal valve construction. 6.6 m3h-1 displacement (60Hz).

Suction pressure regulator

One Suction pressure regulator, brass body, 0-2 bar, spring

Vacuum compressor

One diaphragm type vacuum compressor, 0.24kW motor, 5 m3h-1 displacement (60 Hz), ultimate vacuum: 20 mbar. (Optionally available - Scroll vacuum compressor with ultimate vacuum whilst recovering SF6 of < 1 mbar – allows 99.9% SF6 gas recovery)

Equalization circuit

One Equalization circuit, to allow for high-pressure restarts of the compressor

Discharge check valve

Nine discharge check valve, brass, prevents high pressure going back to compressor when performing a low-pressure equalization.


One High efficiency, 4-pass, air-cooled SF6 condenser to aid in liquification of SF6 at higher ambient temperatures.

Discharge pressure

One High discharge pressure switch set to automatically shut unit down when it reaches maximum allowable pressure

Vacuum Pump

Motor: 1.1 kW, 1750 RPM, TEFC electric motor. Optionally available 40 m3h-1 vacuum pump


  • 30 m3/h (60Hz – 110V)
  • 25 m3/h (50Hz – 220V)

Blank off pressure: 0.08 mbar.
Pump also includes: positive non return valve, isolation valve, gas ballast, and automatic oil return system.

Storage Tank

Cylinders secured onto a tray and manifold, in order to store up to 156 kgs. of SF6 in liquid form indefinitely, at ambient temperatures of less than 114ºF (45.5ºC), without the need for refrigeration. The AGRU-8 shall come equipped with an external storage port, to which any SF6 Gas cylinder or tank rated at 40 bar minimum) can be attached to allow for unlimited storage of SF6. All storage tanks shall include an isolation valve, and an approved safety relief valve.


(D1) & (D2) – Dryer Pre- Filter & Filter - Contains activated alumina to aid in the drying and purification of SF6 Gas

(P1) - Purification Filter - Contains Molecular Sieve 5X to remove arcing by-products

(F1) - Particulate Filter - Will filter all particulate matter down to 0.1 micron nominal


Designed for pressure, temperature and flow. Bronze body with Teflon seats and seals, quarter turn.

Pressure Gauges

One (4” stainless steel) for equipment pressure (compound)

One (4” stainless steel) for discharge pressure

Vacuum Gauge

0-50 mbar for vacuum system

Pressure Regulator

One Pressure Regulator, Brass body, 0-7 bar spring, to allow for safe regulated filling of SF6 equipment.

The standard applications of SF6 Gas Recovery Units in AGRU-8 series are:

  • SF6 recovery and purification :  AGRU-8 series units are efficient at operating a variety of pressures to recover as much as 99.99% of SF6 gas from switchgears.
  • Evacuate Air and Moisture before recovery:  AGRU-8 series recovery units have a preliminary refinement process in place which makes sure that no air or moisture can enter the SF6 gas stream.
  • SF6 purification: All AGRU-8 units have an effective purification assembly that remove impurity particles as small as 0.1 micron in diameter. Thus, only pure SF6 gas is further sent for condensation.
  • SF6 storage: AGRU-8 units comprise of a series of compression and condensation mechanisms that liquefy the extracted SF6 gas for better storage and handling. The liquefied SF6 can then be stored in auxiliary bottles for on-site handling or transport.
  • Regulated filling: AGRU-8 SF6 recovery units have pressure monitors and regulators that maintain safe and appropriate working pressures in all components of the unit. The use of anti-suck-back valves makes sure that the reversal of gas stream is kept in check.

Prominent advantages of using AGRU-8 series SF6 recovery units :

  • The most striking feature of AGRU-8 units is the ease of operation. These units can be handled safely and conveniently by inexperienced operators, too.
  • AGRU-8 units are designed to be ergonomic and compact. They weigh less that 85% of standard industrial units and can be easily moved to and from between various sites of operation. The high-stability pneumatic tyres make sure that the transport through gravels, ditches or uneven roads doesn’t affect the unit itself.
  • Standard input voltage and power make sure that usage is possible across the globe.
  • The pressure regulators and valve systems don’t allow the pressure to build or drop easily, ensuring the safe operation.
  • Oil-free compressors require minimal maintenance.
  • Moisture indicators detect the presence of moisture through colour changes on dial.
  • A host of auxiliary connections and upgrades are available to suit wide varieties of operations.