Tribologie R

Raffinate
Distillate enhanced by chemical and/or physical procedures.
 

Ramsbottom test
Carbonisation test for lubricating oils: DIN ISO 4262; EN 8.
 

Reclaimed oil
Reclaimed used oil is the product of reprocessed used oils. This involves centrifugal processing and filtering of sludge, water and mechanical contaminants. MOTOREX never uses reclaimed oils.
 

Redwood seconds (R”)
A conventional measure for viscosity commonly used in England, Redwood
viscometer.
 

Refining
Hydrocarbons still contain compounds with sulphur, oxygen, nitrogen and other contaminants after distillation and vacuum distillation; these are separated from the hydrocarbons during subsequent refining as a result of chemical-physical processes using solvents or acids, thus improving quality considerably.
 

Reforming
Conversion of hydrocarbons (benzin) with a low octane number into benzin with a high octane number.
a) Thermal reforming: Long-chain paraffin hydrocarbons are converted into aromatics and olefins.
b) Catalytic reforming: Long-chain paraffin hydrocarbons are converted into isoparaffins and aromatics.
 

REFRACTION INDEX
Specifies the deflection of a beam of light of a certain wavelength as it passes through a material, e.g. to identify oils. Provides information on the molecular composition.
 

Refractometer
Device to determine by visual means (calculate the light beam) the oil content of a water-mixed coolant (emulsion).
 

Regular oil
Non-compounded lubricating oil, in some cases high-quality refined products but without active
ingredients (additives).
 

Residual oils
In the context of distilling or cracking, the liquid parts that have not evapor ated, axle oil, bright stocks, etc.
 

Resin formation
Ageing of mineral oil products through the formation of highly polymerised condensation products.
 

Ring sticking
Sticking and formation of residues in piston ring groves; piston rings stick.
 

Roller-contact bearing greases
Lubrication for roller-contact bearings, generally lubricating grease containing lithium soap or, in some cases, sodium soap lubricating grease as well. Calcium soap lubricating grease is suitable for use when subject to exposure to considerable amounts of water.
 

RON
Research Octane Number = Dimension value for the anti-knock properties of petrol, e.g. 95, 98 or 100 RON.
 

Rope grease
Grease to preserve rope made of all kinds of natural fibres and keep it supple. Rope grease is often rapidly biodegradable.

Rust
Corrosion produced by the simultaneous effect of oxygen and moisture on the surface of iron or steel (hydrated ferric oxide).
 

Rust-inhibiting oil
See corrosion-protecting oils and greases.