Case Study 1 (Truck Market)
A sample of engine oil was submitted to the lab following a recent servicing of the equipment as part of a small condition monitoring trial. It was noted that sodium was present, which indicates a coolant anti-corrosion additive. A pressure test was requested to confirm, which showed a significant drop in pressure confirming a coolant leak.
The coolant analysis showed only 17% glycol in the coolant system, significantly below the recommended limit of 50% and also showed evidence of tap-water top-up.The client chose to send another confirmation engine oil sample as well as a coolant sample before replacing any parts. This showed an increase in sodium as well as the presence of Copper, Lead and Tin consistent with bearing wear.
Examination of a bearing from one of the other trucks in the fleet, but not part of the trial, showed similar symptoms and bearing “wiping” before failing. Under the microscope it showed evidence of overheating. The engine repair of this vehicle had cost 26000 GBP.
It appeared the coolant leak had been caused by repeated topup with tap-water rather than pre-mix coolant leading to dilution of glycol causing overheating, pinhole corrosion and a porous liner.
The study was extended to the remainder of the fleet of 2500 vehicles in which 9 similar scenarios were found in the next 3 months of the project
Total saving: 234000 GBP
Na =sodium, Al= Aluminium, Sn=tin, Pb=lead, Cu=copper
Case Study 1a – (Left) pressure of coolant showed significant drop on testing. (right) Bearing shell showed wiping from coolant
Case Study 1b – Analysis of the bearing shell showed evidence of severe overheating.
Case Study 2 (Mining)
A pilot study with an underground mining customer in which over 150 samples across 30 machines were monitored to determine the condition of the fleet (approx. 500 machines in total). The mine manager ran a KPI using the LearnOilAnalysis.com web portal showing the predominant failure flag to be ISO cleanliness code on approximately ¾ of the hydraulic samples. It was found that the samples were approximately 16 times dirtier than the OEM recommendations with the servo valves in use, which greatly increases the risk of failure, seizing & uncontrolled movements.
The laboratory organised a site visit with the client to investigate. The predominant issue was lubricant storage procedures (see images to right). The oil barrels were stored upright allowing debris & water to collect on top (2b), use of dirty open topup cans (2c) & cracked breathers (2d). All potential source of contamination ingress.
The oils in use were predominantly fully-synthetic with long oil life, combating these contamination issues could give potential cost saving in extended drain intervals. Consultations with the mining equipment operators found that most days there was at least one critical piece of equipment down for part of the shift and ~40 engineers were working full time repairing the equipment.
Following the visit the mine implemented improved lubricant storage procedures and a new automated lubricant delivery system to avoid the use of topup cans. LearnOilAnalysis also provided a BINDT ISO 18436 training course in Lubrication Management to a team of 30 engineers to aid in improvement programme. A new KPI ran 6 months after the visit showed an improvement from only 38% of the fleet normal to 88% normal.
Case Study 2a – LearnOilAnalysis.com Analysis by Test KPI showing ISO code cleanliness of oil predominant amber flag cause.
Case Study 2b – Storage drums showing evidence of dirt and debris on barrel top.
Case Study 2c – Dirty topup cans, showing grit and dirt on the handle and within the container.
Case Study 2d – Cracked breather introducing dirt and debris into lube storage tanks.
Case Study 2e – KPI showing significant improvement in lubricant conditions following site visit. Left to right number of normal/caution/serious per quarter.
- 525000 EURO
- extended drain intervals across entire fleet
- 1/3 of services removed.
- Machine availability improved from ~75% to ~85%
Case Study 3 (Industrial)
A pharmaceutical production facility that have been using a Laboratory service service since 1996. Between 2013 and 2015 rises in wear metals were identified in 6 separate gearboxes and a failure was avoided in each. 2 of the examples are listed below. The trending chart data is taken from the providers trending section.
Case Study 3a – LearnOilAnalysis trending charts showing an increase in Copper linked to Silicon and Aluminium. It was found a small amount of dirt / debris had entered the system during a topup/change and caused wear to cage metal. There was also some evidence of iron wear not shown in trend chart above. Owing to the volumes of oil being used, an offline filtration system was fitted to remove this debris. The photograph on the right shows some of the material removed by the filter. Estimated saving 81000 GBP to replace damage components.
Case Study 3b – LearnOilAnalysis trending chart showing an increase in Zinc and Iron. The Iron was linked to topup with lower load carrying lubricant (using ZDDP rather than EP anti-wear additive). The oil was changed and iron levels returned to normal. Gearbox system shown to right. Estimated saving 52000 GBP to replace damaged components.
Total savings: 318000 GBP
Based on 2013 to 2015 avoided failures repair cost for client.
Loss of production costs was not available to calculate any additional savings.
Case Study 4 (Power Generation – Wind)
In 2016 a European based Windfarm as part of their condition monitoring package submitted grease samples from their turbine Front and Rear bearings. High wear was not unexpected as these bearings would commonly have high iron and PQ values due to the operation type. However, it was noted the dramatic difference between the front and rear bearings conditions.
Findings from Analysis Laboratory in UK.
|Test||Front Main Bearing||Rear Main Bearing|
The client then took advantage of the laboratories specialist further analysis capabilities and took the advice of the lab diagnostic support to conduct further analysis on these samples. This further analysis included microscopic analysis of the debris.
Microscopic analysis findings – (Left – Front main bearing, right rear main bearing sample). The Front Main Bearing showed considerable small sized rubbing/sliding wear particles throughout the sample, which if in a smaller concentration would be considered normal. However, owing to the concentration this suggested the lubricant film was being overcome in one bearing and not the other despite both using the same lithium based grease and having been re-greased at the same time.
The findings supported that the Front bearing was being overly loaded compared to the rear main bearing. Discussions with the client identified that the turbine blades had recently been replaced and it was found that the blades were imbalanced in weight by ~40kg. The blade imbalance was corrected and the system was re-greased with a follow-up at next service to monitor the wear trends.
Total savings: 52000 GBP
Based on labour and materials cost to replace the failed bearings. Cost expected to be higher if loss of production costs included.