Multi-Stage Roots Vacuum Pumps

Multi-stage Roots vacuum pumps for clean applications

Multi-stage Roots vacuum pumps from Pfeiffer combine exceptional robustness and high reliability. They are perfectly suited for applications requiring clean, oil- and particle-free vacuum, such as in semiconductor manufacturing or vacuum coating.

Ideal solutions for clean vacuum applications

The ACP series, the A 100 L and A 200 L as well as the TORRI BD pumps are cutting-edge solutions specially designed for clean processes that demand high purity and reliability.

With its variable speed drive, air cooling system and minimal maintenance requirements due to precisely calibrated clearances that ensure contact-free operation, the ACP series delivers consistent performance and durability. These features enable the vacuum pumps to operate efficiently in multiple versions. Each is optimized for specific applications: from handling clean, non-corrosive gases to processing traces of corrosive gases. A gas ballast valve within the ACP improves the pumping of light gases prevents condensation inside the pump. Together, these qualities make the ACP series ideal for dry vacuum processes across industries such as semiconductor manufacturing, medical and pharmaceutical, and R&D.

The A 100 L and A 200 L series feature a compact design and flexible connection options with horizontal or vertical inlets, enabling seamless integration into existing systems. With their exceptional performance and energy efficiency, they are able to quickly process large gas volumes, enabling fast and frequent pump-down cycles in load lock and transfer chambers.

Another solution for load lock chambers are the compact TORRI BD vacuum pumps. They combine high energy efficiency, low ultimate pressure thanks to their proven operating principle, and best-in-class chamber pump-down times.

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Multi-stage Roots vacuum pumps for harsh chemical applications

In semiconductor and coating processes, there are harsh to extremely harsh applications, such as chemical vapor deposition (CVD), that require the use of highly corrosive and aggressive chemicals. This imposes equally high demands on the anti-corrosion protection and temperature control of the vacuum pumps.

Highly reliable dry pumps for harsh chemical processes

Our A4 series multi-stage Roots vacuum pumps offer a highly reliable and efficient solution for processes involving corrosive gases and aggressive chemicals. Thanks to the use of corrosion-resistant materials, these vacuum pumps are well-suited for handling corrosive gases while delivering consistent and reliable performance. Ideal for demanding applications such as semiconductor etching, chemical vapor deposition (CVD), and other harsh chemical processes, the A4 series ensures reliable operation and exceptional durability.

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A multi-stage Roots vacuum pump is a positive displacement pump designed to deliver clean and oil-free vacuum. The pumped medium passes through several stages. In each stage, at least two counter-rotating lobes convey the medium onwards until it is expelled in the final stage. By utilizing multiple stages connected in series, the pump achieves higher differential pressures and lower ultimate pressures than a vacuum booster.

Their robust design combined with anti-corrosion coatings make multi-stage Roots vacuum pumps like the A4 series from Pfeiffer highly resistant to aggressive gases and particles. Thanks to these characteristics, they are ideal for demanding applications that require clean and dry vacuum, such as semiconductor manufacturing, vacuum coating, analytics and R&D.

A multi-stage Roots vacuum pump comprises multiple stages arranged in series. Each stage contains rotating lobes that convey the pumped medium through the pump. Transfer channels regulate the flow of the medium between the stages, and a gear unit synchronizes the movement of the lobes to prevent contact with each other or the housing.

The operating principle can be explained in three steps:

1. Inlet (first stage):

2. Compression in multiple stages:


3. Outlet (final stage):

Multi-stage Roots vacuum pumps are specially designed to handle a wide range of chemicals, including corrosive and aggressive substances. From acids and solvents to gases and vapors, these pumps efficiently and reliably manage a multitude of chemical compounds. The A4 series from Pfeiffer features a particularly robust construction and corrosion-resistant materials, such as special anti-corrosion coatings. Together with temperature control features like integrated heaters, they help prevent condensation and unwanted chemical reactions, like the creation of by-products.

The required multi-stage Roots vacuum pump type depends on the specific process in which it should be used. Different applications demand varying pumping speeds, ultimate pressures, inlet flow capacity and gas handling capabilities. For example, in semiconductor manufacturing, compact multi-stage Roots vacuum pumps with high throughput are preferred for fast pump-down cycles. In contrast, surface analyzers and leak detectors may require versions with specific gas-port options. Additionally, in particle accelerators, models with radiation resistance are essential. Therefore, understanding the unique demands of each application is crucial in selecting the most suitable multi-stage Roots vacuum pump to ensure optimal performance and efficiency.

Multi-stage Roots vacuum pumps from Pfeiffer meet the stringent demands of coating processes, making them an excellent choice for these applications.

1. Clean and dry vacuum: Multi-stage Roots vacuum pumps generate clean and dry vacuum, which is essential for coating processes to prevent contamination.

2. High reliability: Their contact-free operation minimizes wear and ensures consistent performance over extended periods, which is especially important for coating processes where process stability and uptime are critical.

3. High energy efficiency: Many models of our multi-stage Roots vacuum pumps are equipped with variable speed drives, reducing energy consumption. This is particularly important in coating processes that often run continuously or in long cycles. Here, energy savings can have a significant impact on overall operating costs.

4. Durability: These vacuum pumps are designed to handle slightly corrosive gases and condensation. For example, the ACP 120 G is equipped with a nitrogen gas-ballast valve system, and the A4 series features an anti-corrosion coating, which is ideal for coating processes involving condensable or aggressive substances.

5. Compact design: Compact multi-stage Roots vacuum pumps like the TORRI BD, A 100 L and A 200 L can be easily integrated into existing semiconductor systems. This small footprint is particularly advantageous in coating setups where space is limited.

Both vacuum boosters and multi-stage Roots vacuum pumps operate on the same proven Roots principle, using at least two counter-rotating lobes to convey the pumped medium through the system. However, they differ in their design and function:

A vacuum booster used in combination with a backing pump increases the pumping speed and enhances the performance of a vacuum system. Unlike a conventional vacuum pump, it does not internally compress the pumped medium. Instead, it transfers the medium to a backing pump, where the actual compression occurs.

In contrast, multi-stage Roots vacuum pumps consist of several stages connected in series. It compresses the pumped medium within its compression chamber gradually through the stages before it exits the pump.