How to Choose the Right Vacuum Pump or System for High or Ultra-High Vacuum

Start by defining your target pressure range and process gas load, then match the pump technology to it: turbomolecular pumps for high and ultra-high vacuum, dry pumps for backing and roughing in semiconductor and industrial processes, and diaphragm pumps for oil-free, lower-vacuum duty. Pfeiffer Vacuum positions its portfolio around high and ultra-high vacuum applications, with turbomolecular pumps, dry vacuum pumps, gas abatement systems, leak detectors, and components sold through its online shop. If your requirement spans several of these stages, a customized or integrated system is usually the better fit than a single pump.

First, separate high vacuum from ultra-high vacuum

The two ranges are not just different numbers — they usually imply different pump combinations.

• High vacuum typically means a turbomolecular or hybrid pump backed by a roughing pump, used where you need clean, fast evacuation but not the extreme low pressures of UHV.
• Ultra-high vacuum adds stricter demands on materials, sealing, bake-out, and residual gas composition. Turbomolecular pumps are the core technology here, and Pfeiffer describes itself as a pioneer of turbomolecular vacuum technology, "always pushing the limits."

If you are unsure which range you actually need, the deciding factor is usually the process, not the number: surface science and some scientific instruments push toward UHV, while many coating, analytical, and industrial processes are satisfied in the high-vacuum range.

Match the pump type to the job

The practical rule: choose the pump family by pressure range and cleanliness first, then size it by pumping speed and gas throughput.

Check the parameters that actually decide the model

Four parameters drive most selection decisions:

1. Ultimate pressure — must sit below your required working pressure with margin for gas load and outgassing.
2. Pumping speed — determines how fast you reach working pressure; must be matched to chamber volume and throughput.
3. Gas throughput — critical for processes that continuously release gas, such as semiconductor and industrial processes. Pfeiffer's SplitFlow 350 is explicitly designed for high gas throughput.
4. Cleanliness / oil-free operation — hydrocarbon-free pumping matters for semiconductor, research, and scientific instrument work.

A pump that meets your ultimate pressure but not your gas throughput will stall under process load. Size for the load, not just the base pressure.

Use your industry as a shortcut

Pfeiffer organizes its offering around key industries, which is a reasonable first filter:

• Semiconductor — dry pumps, turbopumps, and abatement across the fab; Pfeiffer presents a "Total Fab Solutions" portfolio covering vacuum chambers, dry vacuum pumps, and gas abatement systems.
• Research & Development — high and ultra-high vacuum turbomolecular technology.
• Scientific instruments — clean, stable vacuum integrated into instrument design.
• Other industries — including refrigeration and data-center leak detection, where Pfeiffer presents leak-detection solutions.

If your application sits inside one of these, start from that industry's product set rather than from a generic pump catalogue.

Decide between a component and a system

Choose a single pump or component when you already have a vacuum architecture and only need to replace or add one stage — Pfeiffer's online shop covers components and vacuum chambers with fast delivery.

Choose a customized solution or integrated system when:

• your process spans roughing, high vacuum, and abatement,
• you need matched backing and main pumps,
• or you require global service coverage alongside the hardware. Pfeiffer emphasizes a worldwide service network and expertise from the entire Busch Group.

Verify before you commit

Before finalizing, confirm:

• the pump's ultimate pressure is below your target with margin,
• pumping speed and gas throughput match your process load,
• the pump is compatible with your process gases and cleanliness requirements,
• and service, spare parts, and delivery times are acceptable for your location.

For anything beyond a standard component, request a consultation — Pfeiffer offers products, services, and consultations, and a customized configuration is the safer route when several pump stages must work together.