Slot Cleaning

It is imperative to eliminate absolutely every trace of carbon vane dust and particles from the rotor slots. Use powerful, dry compressed air.

Inlet Filters

Do not clean filters; replace them. A saturated filter causes a pressure drop (Delta P) that forces the pump to overwork, drastically raising internal temperature.

Bevel Orientation

Critical Point: The higher part of the blade bevel must always face the direction of rotor rotation. Mounting the vanes backwards is fatal.

Rotor Inspection

Examine rotor slots under powerful light. Look for "washboarding". If present, the new carbon vane will vibrate and eventually stick or break.

Temp. Control

Monitor exhaust temperature. It should not exceed 120-130°C. Higher temperatures indicate excessive friction on the blades.

Shaft Bearings

Check radial and axial clearance. If there is play, the rotor loses its center and will strike the cylinder ("chattering"), pulverizing the carbon vanes.

Dimension Check

Measure the height of the old blades and compare with the minimum specification to determine if replacement is due to wear or premature breakage.

Cylinder Condition

Run your finger along the stator interior. It must be mirror-smooth. If you feel grooves, the surface acts like sandpaper against new carbon vanes.

Motor Coupling

Inspect the elastic transmission elements (spiders). A worn coupling transmits shock loads and torsional vibrations directly to the rotor vanes.

Regulating Valve

Verify the vacuum relief valve setting. If improperly adjusted, the pump may operate outside its design curve, leading to severe overheating.

Exhaust Filters

Ensure they are not saturated. High exhaust backpressure restricts airflow and causes the motor to draw excessive amperage.

Side Clearance

Insert the new carbon blade into the clean slot. It should drop by its own weight. If force is needed, the vane will seize when hot.

Cover Gaskets

Never reuse damaged gaskets. A vacuum leak in the cover alters internal airflow and cooling efficiency. Always use new gaskets.

External Radiator

Blow compressed air through the external cooler (counter-flow). Accumulated dust acts as a thermal blanket, preventing heat dissipation.

Room Ventilation

If the technical room ambient temperature exceeds 40°C, the pump cannot cool properly. Consider installing forced extraction.

Rotor Burrs

If small nicks are detected at the slot entries, use very fine sandpaper. A sharp edge acts like a guillotine on the new blade.

Non-Return Valve

• The Issue: Upon shutdown, negative pressure causes backflow that reverses rotor rotation and damages the carbon blades.

• The Solution: It is essential to install a non-return (check) valve or verify its spring closes correctly.

Consumption (Amps)

Use a clamp meter. Consistent high amperage indicates something is braking the rotor: tight vanes, clogged filters, or seized bearings.

End Plate Wear

Inspect the side covers. If the vane has "dug" a deep groove, gas will leak past the rotor. The plate must be ground or resurfaced.

Safe Storage

Carbon vanes are hygroscopic. Keep them in sealed bags until assembly. A blade swollen by humidity will jam in the slot.

Solvent Usage

Use fast-evaporating, residue-free cleaners. Any liquid remaining inside will form a paste with the carbon dust.

Rotation Direction

If the motor was disconnected, confirm rotation with a quick "jog" start. Spinning in reverse will destroy a new set of carbon blades.

Initial Break-in

Let the pump run for 20 mins in "free running" mode (open intake). This seats the vanes in the stator without maximum pressure load.

Piping Stress

Ensure pipes do not exert force on the pump. This deforms the housing, reducing tolerances and causing rotor seizure.

Grease Points

Only if greasable bearings are present, apply the exact amount. Excess grease is as damaging as a lack thereof due to viscous friction.

Maintenance Log

Record hours and dates. Keeping a log allows you to predict the real service life of the carbon vanes and schedule the next change.