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Mobile Equipment Engine Kit Case Study

Mobile Equipment Filtration – Engine Kits (ENG-2) Large Surface Coal Mine


Large Surface Coal Mine
Montana, USA





Coal takes miners deep into the bowels of the earth, and scrambling around a coal mine is, without a doubt, some dirty business.

Jessika Toothman

Top 10 Dirty Jobs: Manufacturing ,

The Challenge

Mines are home to one of the harshest industrial environments, yielding large amounts of dust, dirt, debris and water. Contamination control in mines can be a constant, everyday battle. Des-Case takes very seriously the challenges our customers face, and for over 25 years has provided the contamination control industry with innovative product designs that will battle even the most demanding industrial environment.

When a 25,000 acre surface coal mining operation in Montana was in search of a solution to extend equipment life and lower overall maintenance costs on their mobile equipment fleet, they turned to AMS Filtration, A Des-Case Company, to improve their diesel engine reliability.

The mining company conducted oil analysis to determine the service life of their engines was being cut short by particles the OEM full flow filtration was not designed to remove. Their vehicles included several drag-line excavators, bulldozers, haul trucks and loaders. The first vehicles analyzed were the CAT 992G bucket loaders − equipped with 3508B engines that hold 27 gallons of an SAE 15W40 engine lubricating oil. Oil analysis on one 992G in the mine’s fleet indicated a particle count by pore blockage method of 22/21/18 with copper and iron levels at 118ppm and 53ppm, respectively. Oil analysis on the other loaders indicated similar conditions.

The Solution:

Des-Case Corporation manufactures customizable filtration solutions for all industry applications, including innovative dedicated filtration kits specifically tailored for mobile equipment. One such system, the ENG-2, was installed to filter the engine oil.

The Des-Case ENG-2 mobile equipment engine kit provides filtration with depth media for a constant contamination control solution at very low ISO cleanliness levels. The system works by taking approximately 10% of the oil flow after the OEM full flow filter and directing it through the ENG-2 system. Oil flows through the canisters at a set rate and is returned directly to the engine sump. The system is designed to prevent the canisters from being emptied when the equipment is shut down, while the small amount of oil directed through the ENG-2 system at any given time ensures the engine is never starved of oil. A pressure relief valve is also installed to prevent accidental over pressuring of the canisters during cold cranking.

The ENG-2 is a depth type secondary (slip-steam) filtration system. The system is designed to meter engine oil flow through the filters at ½ GPM. This slow flow rate, combined with the depth filtration, allows the system to have significant impact on soot and particles less than 1 micron in size.

Target cleanliness targets at the time of installation were established at ISO 19/17/14 (c) which, compared with the engine oil cleanliness prior to installation of ISO 22/21/18 (c), should yield a sixteen-fold reduction in particle contamination within the engine, resulting in a projected three-fold extension of the engine life.


Product Specifications:
  • Two swing bolt lid filter canisters with two wound cellulose depth elements

  • 50 psi pressure relief valve

  • ½” NPT plumbing connections

  • Flow control orifices at inlet

  • Designed to prevent empty canisters at engine shut down

Engine Kit Filter Media – Wound Cellulose Depth Media
  • High efficiency filtration at very low micron levels (≤1 micron)

  • Ideal for filtering petroleum-based fluids

  • Performance to β<3(c)=1000 (per ISO 16889)

  • Dirt holding capacity up to 10lbs per element

  • Absorbs up to 1 gallon of water per element

  • Can maintain moisture levels below 50 ppm

The Results:

After 931 hours, oil analysis was conducted to determine ISO cleanliness levels went from ISO 22/21/18 (c) to ISO 17/16/13 (c), soot levels were maintained at or below 0.1% vol, copper levels dropped from 118ppm to 2ppm, and iron levels dropped from 53ppm to 7ppm. Based on life extension projections, cleanliness levels of ISO 17/16/13 (c) in an engine should result in a four-fold increase in engine life.

Purchase and installation costs of the AMS Engine filtration kit were approximately $ 3,000, with an annual replacement element cost of about $1,000-$2000. A typical “top end” overhaul costs at minimum $ 12,000 – $ 15,000. Based on the target cleanliness levels achieved, the top end overhaul interval is projected to increase from an average of 13,500 to 54,000 hours, resulting in a net present value savings across the mines fleet of six loaders of $129,841 over 5 years, at an annualized rate of return of 216%. To date, the mine has been able to sustain the improved levels of fluid cleanliness achieved with the Des-Case Mobile Equipment Engine Kit and has paid off the investment in the system in a little over 5 months.

Standard OEM Filtration
Secondary Filtration
with ENG-2
ISO Cleanliness Code 22/21/18 17/16/12
Hours on oil 306 931
Soot Levels ≤0.1%
Copper Levels 118ppm 2ppm
Iron Levels 53pm 7pm
Life Extension $9,733 4x
Annual overhaul costs $2,433
5-year Net Present Value (NPV) Savings (6 loaders) $129,841
Internal Rate of Return (IRR) $219