01
Leak rate: definition and engineering context
Air or vacuum leakage rate. Rate at which gas enters or escapes a system under stated conditions.
The term belongs to the vacuum context. Its exact limits can depend on the cited standard, catalog convention, unit system, reference state, and component configuration.
02
Why Leak rate affects pneumatic selection
It sets pump/ejector demand and pressure retention time.
- Vacuum level: Record the reference and unit; percentages of vacuum can hide assumptions.
- kPa abs: Lower absolute pressure means a stronger vacuum.
- Holding force: Derate for acceleration, orientation, leakage, surface texture, and cup geometry.
- Safety factor: Choose it from motion, surface, failure consequence, and application guidance.
03
How to evaluate Leak rate in a catalog or replacement project
Read the value together with its unit, test basis, operating pressure, temperature, circuit state, and manufacturer definition.
For replacement work, compare the complete datasheet and drawing. A matching abbreviation or nominal size does not by itself prove functional or dimensional interchangeability.
- Pressure below atmosphere: Magnitude of sub-atmospheric pressure stated as gauge vacuum or absolute pressure.
- Kilopascals absolute: Absolute-pressure unit commonly used for vacuum work.
- Vacuum-cup holding force: Ideal pressure-difference force over effective cup area before losses and safety factors.
- Design factor: Multiplier between calculated minimum and selected capacity.
Selection checklist
What to verify before selection
- 01
It sets pump/ejector demand and pressure retention time.
- 02
Record the reference and unit; percentages of vacuum can hide assumptions.
- 03
Lower absolute pressure means a stronger vacuum.
- 04
Derate for acceleration, orientation, leakage, surface texture, and cup geometry.
Application caution
Common mistakes
- Treating Leak rate as a universal definition without checking the manufacturer or standard context
- Mixing gauge and absolute values, incompatible units, or different reference conditions in one comparison
- Selecting a component from the term or nominal value alone without checking the complete operating point and drawing
FAQ