A useful vacuum-pump enquiry starts with the process. What are you pumping, what pressure do you need, and how much time do you have to get there?
A model number helps when replacing existing equipment. For a new application, a short description of the job is often the best starting point.
Describe what happens inside the system
“Laboratory use” or “industrial vacuum” leaves a lot unanswered. Explain what the equipment does and what the pump will encounter. Evacuating a clean, dry vessel is a different duty from removing water vapour during drying or handling solvent vapour from an evaporation process.
Name the gases and liquids involved. Mention dust, droplets or other material that could reach the pump. If the composition varies during a cycle, describe that too. This affects the choice of pump technology, materials and equipment needed between the process and pump.
State the pressure you need during operation
The lowest pressure a pump can reach is not necessarily the pressure at which it will do most of its work. A system may evacuate an empty chamber and then admit process gas. Another may release vapour continuously as a product dries.
Give the normal operating pressure and any lower pressure needed before the process starts. Include the units and say whether the reading is absolute or relative to atmospheric pressure. Our guide to pumping speed and ultimate pressure explains the distinction.
If you do not know the required pressure, describe the result you need to achieve. That is more useful than guessing a number.
Include chamber volume and cycle time
A 20-litre vessel and a 200-litre vessel present different evacuation duties, even when both need to reach the same pressure. Give the chamber volume, starting pressure and time available for evacuation. Include connected volumes where significant.
Explain how often the system returns to atmosphere. Equipment opened between every batch may need a different selection from equipment that remains under vacuum for days. For drying, the amount and rate of vapour released can be a major part of the requirement.
Be specific about cleanliness and installation
If oil contamination would affect the process, explain what is sensitive: the sample, a coating, an analytical measurement or the finished product. A dry pump may be appropriate, but chamber materials, seals, previous use and handling also matter.
A photograph or sketch of the connection can save several rounds of questions. Include pipe length and internal diameter, plus valves, filters and traps. For a replacement, check available space, electrical supply, exhaust arrangements and maintenance access.
Tell us whether the pump will run continuously, cycle frequently or be used occasionally. Include any noise or vibration constraints and describe difficulties with the existing equipment.
A short brief you can send
| Detail | What to provide |
|---|---|
| Application | What the equipment does |
| Process media | Gases, vapours, liquids and possible particles |
| Pressure | Operating and starting requirements, units and pressure reference |
| Volume and timing | Chamber size and required evacuation time |
| Duty | Operating hours and frequency of cycles |
| Cleanliness | Sensitivity to oil or other contamination |
| Installation | Connections, space, power and exhaust |
| Existing equipment | Pump model and reason for replacement |
Send Girovac the information you have, together with photographs if helpful. Leave unknowns marked as unknown. A clear account of the application gives us a sound starting point for discussing suitable equipment.
Technical reference: Leybold, Fundamentals of Vacuum Technology, 2016 edition, sections 2.1–2.3. Leybold’s online vacuum fundamentals provides further reading.
Updated September 2026. Model-specific settings and limits must be checked against the equipment’s operating instructions.