Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/1475671
4 | July - August 2022 | www . machinerylubrication.com Problem Loss of oil clotting/ packing Impaired seal performance (e.g., dimension change, structural change, deterioration, compression set issues, etc.) Sludge mobility (sludge and deposits become mobilized by change in lubricant chemistry) Impaired lubricant performance due to clashing additives and base oils Perform a chemical flush and repair leakage before the machine is returned to service Run tests for compatibility to elastomer types used in the machine; repair/ replace old and worn seals High-velocity flush, chemical flush and other flushing methods needed to purge system of sludge and deposits before new lubricant is introduced Complete drain and flush of all remnants of the previous lubricant Old machines; switching from mineral oil to formulations with esters, detergents, dispersants and other polar additives Old machines; switching to a synthetic lubricant that has a sharply different aniline point than the previous lubricant Old machines; switching from mineral oil to formulations with esters, detergents, dispersants and other polar additives Incompatible lubricant mixtures such as acid/ base reactions Oil leakage (both internal and external) and potential starvation Oil leakage (both internal and external) and potential starvation Clogged oil flow through glands and orifices resulting in starvation and accelerated wear Possible reliability issues from: • Production of sludge and other insolubles • Loss of interfacial tension leading to chronic aera- tion problems, foam and/ or oil-water emulsions • Impaired oxidation stability • Corrosion • Impaired film strengh Greatest Danger Consequences Controlling the Risk AS I SEE IT surface treatments, filters, elastomers, caulking, adhe- sives, etc.). Some aggressive lubricant additives can leach sensitive metals (tin or copper, for instance). • e backup lubricant was incompatible with oper- ating conditions a nd exposures (temperature extremes, contaminants, gases, process chemicals, washdown sprays, cool- ants, etc.). • e backup lubricant had performance weaknesses or drawbacks that the previous lubricant did not. While some characteris- tics of the new lubricant may be superior to the previous lubricant, many ot hers cou ld ex hibit substandard performance. e highest risks coming from backup lubricant change- overs are associated with: • Old equipment (long service with the previous lubricant) • Unknown additive chem- i s t r y a n d l i m i t e d c ompat ibi l it y te st i ng performed • High machine duty and criticality • Complex lubricant formu- lations Verify Compatibility in Advance T here a re nu merou s industry standards that provide guidance on compatibility testing (ASTM, FTC, etc.). e typical protocol for oil (e.g., ASTM D7155) involves Figure 2.