Case Study: Extended Drain Interval

This case study outlines the use of SEM-EDS Wear Analysis in an extended drain interval trial.

Background

Our client, a large open pit mining company, operates a fleet of approximately 80 active mining haul trucks. The company sampled their engines every 250 hours and changed oils every 500 hours. In the spring/summer of 2021, they conducted an extended oil drain interval project to determine if it was possible to extend drains from 500 to 750-800 hours.

Project Overview

A select group of 797 mining haul trucks were included in the project. In addition to routine oil analysis testing, SEM-EDS Wear Debris Analysis was done to monitor the condition of the oil at the “extremes” (i.e. worst case scenario: 100+ hours past the 750 hour planned interval).

Trial Actions

Engines in the select group of haul trucks were sampled at approximately every 250 hours during the trial. SEM-EDS analysis confirmed that at the 750+ hours interval did not increase iron, lead, soot % contamination to dangerous levels across the selected test trucks. The SEM-EDS results showed that across all trucks, oil condition was reasonable with regards to signs of wear and contamination, but not to the point of severe degradation.

Outcomes

Routine traditional oil analysis coupled with SEM-EDS analysis validated that oil drain intervals could be extended with negligible effect on oil condition and wear. The company decided to implement a 750-hour engine oil drain interval based upon this study. This modified oil drain schedule allowed for a reduction of six “level 1” PMs per year which results in 480 less PMs per year for the entire truck fleet. Routine oil analysis continues to be done to ensure the condition of the oil is being monitored.