Compressor
A flexing diaphragm draws and displaces air through check valves. Oil-free, hermetic, low flow.
Typical range
0.1–5 HP, to ~150 PSIG (single-stage), low CFM
Best for
Lab, medical, gas sampling, hermetic oil-free low-flow.
Operating principle
A flexible diaphragm flexed by a crank/eccentric draws and displaces air through check valves. The compression chamber is isolated from the drive — oil-free by design. Often multi-headed for flow.
Efficiency notes
Low CFM, low pressure; high purity (oil-free, leak-tight). Good for low-flow clean air where leakage must be zero.
Selection guidance
Sampling, lab, medical, gas transfer where oil-free and hermetic separation matter. Low pressure, low flow.
Components
- Diaphragm (PTFE/rubber)
- Check valves (reed)
- Eccentric/crank drive
- Sealed bearings
- Head/valve plate
Common issues
- Diaphragm rupture → flex fatigue, overpressure, debris
- Check valve failure → loss of capacity, backflow
- Pulsation → inadequate dampener
Maintenance
- Inspect diaphragm per OEM (typ. 2,000–4,000 hrs)
- Keep inlet clean — abrasives cut the diaphragm
- Replace check valves when capacity drops
Field tips
- Keep intake clean — abrasives cut the diaphragm
- Add a pulsation dampener for smooth discharge
- Hermetic separation makes this the cleanest low-flow option