- Easily used by ships maintenance staff right out of the box
- Instant indication of condition for motor bearings, gears, compressors, slewing rings, hoists, winches...
- Plan maintenance and have the spares available on time. Minimise off-hire and demurrage.
Glycol Detection Sensors
On-Line – Glycol detection via sensor can be indirectly accomplished by noting a sharp change in dielectric constant, as determined by ‘oil condition’ sensors. The reading should then be vetted via direct testing for glycol, water and other possibilities.
On-Site – There are numbers of useful ways to test for lube oil glycol at this tier, including
- Paper Chromatography (“blotter test”), wherein a drop of oil is placed on blotter material. The oil drop will expand concentrically on the blotter. Certain characteristics or colours observed will be suggestive of glycol contamination
- Schiff’s Reagent: a reaction involving conversion of glycol to aldehyde causes a colour change in the Reagent from clear to pink to red to purple. Red and purple indicate high amounts of aldehyde (glycol*). One-shot test kits are commonly available. *False positives can occur in certain fresh oils
- Portable infrared spectrometric devices
Off-Site – Several possibilities exist:
- Gas Chromatography: This instrument is capable of very high precision with glycol (and fuel) contamination, provided there are no interferences from other of the in-service oil’s contaminants
- Infrared Spectroscopy (IR/FTIR) – Provided proper referencing is accomplished, and provided there are no other interfering constituents, FTIR has become a popular method for glycol determination because numbers of other inspections for lube degradation and contamination can be performed simultaneously
- UV Emission or Absorption Spectroscopy – Most glycols used for water jacket heat dissipation will have some combination of potassium (K), sodium (Na), boron (B) or silicon (Si), sometimes-even molybdenum (Mo), as part of an additive package for inhibiting corrosion and other desirable features. These elements have proven to be excellent and sensitive inferential indicators of glycol presence with relatively little interference (false positives)
Reporting Units: Glycol is most often reported as POS or NEG, unless gas chromatography or infrared spectroscopy is used, in which case reporting units might then be in ppm or % from GC, or AU (Absorbance Units) from FTIR.
Discussion: Glycol is usually of concern in reciprocating, liquid-cooled engines and compressors, as well as auto-powershift transmissions with oil coolers. It can enter the oil sump under a variety of conditions:
- Pinholes or other compromise in cooler cores. Most heavy-duty cooler cores are copper (Cu), and sometimes Cu levels in the oil, absent lead (Pb) in corresponding proportion, will help corroborate this particular problem source
- Leaking or blown head gaskets, or loose heads
- Liner or block cracking
- Injector seal/tube
- Liner cavitation
Significant lube oil glycol can wreak havoc in an engine, first causing oil thickening and loss of lubricity, but later forming a very tacky, resinous material with the lube that is capable of causing engine seizure and abrupt stoppage (or rod-through-the-block ruination) at either a piston-liner or bearing-shaft interface.