The Ultimate Guide to Two-Stage Rotary Vane Vacuum Pumps: How They Work and Applications

Posted by FLUIDX on 25th Aug 2023

Vacuum technology plays a pivotal role in the world of industrial and scientific processes. 

Whether it's in manufacturing, research laboratories, or even medical applications, the need for efficient and reliable vacuum pumps cannot be overstated. Among the various types of vacuum pumps available, the two-stage rotary vane vacuum pump stands out for its exceptional performance and versatility. In this comprehensive guide, we will delve into the inner workings of two-stage rotary vane vacuum pumps, explore their operational principles, and highlight their diverse range of applications.

What is a Two-Stage Rotary Vane Vacuum Pump?

A Two-Stage Rotary Vane Vacuum Pump is an oil-sealed vacuum pump used in many laboratory, scientific and production vacuum systems. These pumps have both a high and low-pressure vacuum stage, which improves the vacuum pump performance. The rotor chambers are lubricated with a specifically formulated oil which acts as a sealant and lubricant between the sliding vanes, pump rotor and stator. Most laboratory rotary vane pumps are direct drive coupled pumps and typically get to a base pressure of near 1 x 10-3 torr (1.3 mbar).

How does a Two-Stage Rotary Vane Pump Work?

The pumping action works on the principle of reducing the gas by gradually increasing the pump volume within the pumping cavity. The vanes rotate inside the stators and slide within the rotors. They are sealed by a specifically formulated, low vapor pressure oil, which acts as a sealant, lubricant, and coolant for the vacuum pump (You can find the right oil for your pump here). The two-stages are the high pressure and the low pressure. Gas enters the inlet or suction chamber (high pressure stage) and is transferred to the low-pressure stage where it is immediately compressed by the vane of the rotor and expelled to atmospheric pressure. The second stage improves base pressure or vacuum level of the pump.

Applications of Two-Stage Rotary Vane Vacuum Pumps

The versatility of two-stage rotary vane vacuum pumps is a testament to their engineering excellence. These pumps find their place in a plethora of applications across diverse industries. Below are some of the most common applications

1. Analytical Instruments:

In laboratories and research facilities, these vacuum pumps are used to create a controlled environment for analytical instruments such as mass spectrometers, electron microscopes, and surface analyzers. The pumps facilitate accurate measurements and analyses by ensuring a clean, stable vacuum.

2. Vacuum Furnaces and Metallurgy:

Two-stage rotary vane vacuum pumps are indispensable in metallurgical processes and vacuum furnaces. They aid in the production of high-quality, pure metals by maintaining controlled environments free of impurities and oxygen.

3. Food Packaging and Processing:

In the food industry, these pumps are employed for vacuum packaging, extending shelf life by removing air from packaging containers. They are also used in freeze-drying processes to preserve food items and maintain their nutritional value.

4. Pharmaceuticals and Chemicals:

Two-stage rotary vane vacuum pumps contribute to pharmaceutical production, distillation, and purification processes. They assist in creating precise conditions for drug synthesis, distilling solvents, and drying chemical products.

5. Semiconductor Manufacturing:

Semiconductor fabrication demands an ultra-clean environment, making these pumps vital for wafer processing and deposition. They help maintain vacuum chambers during the creation of microchips and other electronic components.

6. Environmental Testing:

These pumps are used in environmental testing chambers, where controlled vacuums simulate extreme conditions like outer space or high-altitude environments. Such chambers are essential for testing the resilience of various materials and equipment.

Considerations When Selecting Your Pump

As you look at applications, here are the items you should consider when selecting your rotary vane vacuum pump.

  1. Vacuum Level: Choose based on required vacuum range.
  2. Pumping Speed: Ensure efficient gas removal for your process.
  3. Gas Compatibility: Pick materials and oil compatible with gases.
  4. Ultimate Pressure: Match pump's pressure capability to your needs.
  5. Noise and Vibration: Consider impact on workspace.
  6. Maintenance: Evaluate ease, parts availability, and service.
  7. Size and Portability: Account for space and transport requirements.
  8. Power Requirements: Check power supply compatibility.
  9. Cost and Budget: Balance cost with suitability and long-term expenses.
  10. Support and Warranty: Prioritize reliable customer support and warranty.


Two-stage rotary vane vacuum pumps are versatile tools that find applications in a wide array of industries, from scientific research to manufacturing and beyond. Their ability to create and maintain controlled vacuums plays a pivotal role in achieving precision, purity, and reliability in various processes. By understanding the inner workings of these pumps and exploring their diverse applications, we gain a deeper appreciation for their significance in modern technology and industry.