What is the function of a vacuum pump?

A vacuum pump removes gas molecules from a sealed space to create a partial vacuum, enabling processes that require low pressure. In practical terms, it pulls air and other gases out of a chamber so the pressure inside can be much lower than atmospheric. This enables a wide range of manufacturing, laboratory, and industrial applications.

What a vacuum pump does

Vacuum pumps create a pressure difference that draws gas out of a chamber, lowering the internal pressure relative to the outside environment. They are used to keep chambers free of contaminants, to remove moisture or volatile components, and to support processes that would be compromised by air or oxidation.

• Positive displacement pumps: These traps and expel a fixed volume of gas with each cycle. They include diaphragm pumps, piston pumps, and rotary vane pumps and are often used for rough vacuum.


• Momentum transfer pumps: These remove gas by imparting momentum to gas molecules, effectively expelling them from the chamber. Examples include turbomolecular pumps, diffusion pumps, and ion pumps, which are common for high to ultra-high vacuum.


• Backing and combination systems: Many high- or ultra-high vacuum setups use a backing pump (often a scroll or rotary vane pump) to support the high-vacuum stage.

Understanding these pump types helps you match a pump to the process’s vacuum requirements and maintenance needs.

How vacuum levels are categorized

Vacuum levels are described in pressure units such as mbar or Torr. The main categories guide which pumps are appropriate for a given job:

• Rough vacuum: from atmospheric pressure down to roughly 1 mbar. This range is commonly served by basic rotary vane, diaphragm, or scroll pumps.


• High to very high vacuum: from about 1 mbar down to around 10^-3 to 10^-6 mbar, depending on the system. Turbomolecular, diffusion, and ion pumps are typical choices here, often with a backing pump.


• Ultra-high vacuum (UHV): below about 10^-3 mbar, extending to 10^-10 or even 10^-12 mbar in specialized setups. UHV systems rely on advanced turbomolecular or ion pumps, getter pumps, and careful materials handling.

These ranges help determine equipment selection, system design, and maintenance requirements for achieving and sustaining the desired vacuum level.

Common applications

Vacuum pumps enable a broad spectrum of activities across industries and research institutions. Here are some of the most common uses:

• Vacuum drying and degassing of liquids and solids to remove moisture and entrapped gases.


• Thin-film deposition and coating (sputtering, evaporation, chemical vapor deposition) for electronics, optics, and solar cells.


• Material processing under reduced pressure to prevent oxidation or contamination during manufacturing.


• Laboratory research, including mass spectrometry, electron microscopy sample prep, and vacuum-assisted spectroscopy.


• Industrial processes such as vacuum packaging, food preservation, and drying electronic components.


• Semiconductor and LED production, which require precise vacuum environments to control films and impurities.

The wide range of applications underscores why vacuum pumps are a staple in modern science and industry.

Safety and maintenance

Safe operation and regular maintenance extend pump life and safeguard process integrity. Key considerations include:

• Follow manufacturer guidelines for startup, shutdown, oil changes (for oil-sealed pumps), and filter replacement.


• Check for leaks and ensure seals are intact; leaks compromise vacuum quality and can damage pumps.


• Handle oils, vapors, and any process gases with appropriate PPE and ensure proper ventilation in the work area.


• Prevent overheating by allowing adequate cooling and avoiding blocked cooling paths.


• Be mindful of backstreaming of pump oil into the chamber; use traps or oil separators where needed.


• Observe electrical safety, grounding, and compliance with hazardous materials handling for gases involved in the process.

regular maintenance and proper safety practices protect personnel and ensure consistent process results.

Choosing a vacuum pump

Selecting the right pump depends on the required vacuum level, pumping speed, gas composition, presence of moisture or contaminants, space, noise considerations, power availability, and whether oil-free operation is necessary for cleanliness. In many setups, a combination approach—using a roughing pump backed by a high-vacuum pump—offers flexibility and reliability.

Summary

A vacuum pump serves to create and sustain low-pressure environments by removing gas from a closed space. By selecting the appropriate pump type and managing maintenance, industries can accomplish processes ranging from drying and degassing to high-precision thin-film deposition and semiconductor fabrication. Understanding pump categories, vacuum levels, and safety considerations helps ensure effective, safe, and efficient operation.

Why do you use a vacuum pump?

Simply put, vacuum pumps are mechanical devices that enable the removal of air and gas molecules from a sealed area to create an area devoid of air and/or gas. Generally, their purpose is to clean and seal. Vacuum pumps come in wet or dry variants depending on the media being pumped through them.

What happens when the vacuum pump goes bad?

When a vacuum pump fails, the system it supports will stop functioning correctly, leading to a range of problems such as reduced braking assistance, poor engine performance, and climate control issues. In critical applications, such as aviation, this can mean the loss of essential navigation instruments. In industrial or laboratory settings, a pump failure can result in loss of vacuum, system contamination, or process failure. 
Symptoms of a failing vacuum pump

• Decreased performance: Loss of vacuum, difficulty stopping, lack of acceleration, and rough engine idle. 
• Mechanical issues: Increased noise, vibrations, overheating, or liquid leaks around the pump. 
• System-wide problems: Climate control may default to the defroster, and a check engine light may illuminate. 
• Catastrophic failure: In some cases, like a MINI N14 engine, failure can lead to severe engine damage. 

What happens in different scenarios

• In a vehicle: A failing pump can cause a hard or stiff brake pedal, reduced engine power, and issues with the climate control system. 
• In an aircraft: The failure of a dry vacuum pump can lead to the loss of gyroscopic instruments like the artificial horizon and turn-and-bank indicator. 
• In industrial or lab settings: Failure can result in a loss of vacuum, leading to process interruptions, contamination due to leaks, and increased energy consumption. 

You can watch this video to learn about the symptoms of vacuum pump failure in a car: 1mAuto Info GuyYouTube · Jan 12, 2023

How much horsepower do you gain with a vacuum pump?

“In a 600-800 horsepower engine, the combination of crankcase vacuum, improved ring seal, and low-tension rings can net between 15-25 extra hp. Even on an engine with rings that haven't been optimized for a vacuum pump, you can pick up at least 10-15 hp.”

What is the main function of a vacuum pump?

A vacuum pump is a device that removes gas molecules or air particles from a sealed volume in order to achieve difference in pressure creating a partial vacuum. Vacuum pumps are designed in a variety of technologies based on the pressure requirements and the application it services.