Desiccant Breathers Prevent Bulk Fluids Moisture from Damaging Machine Components

1.0 Introduction

A desiccant breather on a bulk oil tank

The best way to reduce machine powertrain cost per hour is to maximize component life and utilize all of the value built into the component. Avoiding premature component failure is essential to maximizing component life. There are many variables that contribute to premature component failure. One of those variables is corrosion damage of highly loaded precision components, such as bearings or fuel injectors.
Bearings are susceptible to corrosion damage from water in lube oils, and fuel injectors may be damaged by excess water in fuel. Keeping moisture out of bulk fluids is essential to prevent damage to machine components.

The use of desiccant breathers on bulk fluid storage tanks prevents atmospheric moisture from entering the tank and contaminating the fluid. Also preventing atmospheric moisture from entering bulk fluid storage tanks during normal fill and drain cycles will prevent failures due to corrosion. These practices will help extend component life, reduce cost per hour, and improve machine availability.

2.0 Best Practice Description

A desiccant breather beginning to change color

Many bulk fluid storage tanks at dealer and customer facilities have breathers with unfiltered tank vents. This allows both airborne dirt and moisture to enter the tank and contaminate the fluid. This can be easily corrected by installing desiccant breather filters to the tank vent. Desiccant breathers come in a wide variety of sizes and arrangements. The most common is a disposable spin-on unit that changes color as the desiccant capability is depleted. This allows for easy visual inspection to determine if the unit is functional or requires replacement.

Filter sizing is determined by:
• The maximum flow rate of air into or out of the tanks during usage or refill.
• The pipe or fitting size of the vent pipe where the breather will be attached.

3.0 Implementation Steps
Desiccant breathers are not available through the Caterpillar parts system. They are available from several outside suppliers. Two of the most common suppliers are Des-Case and Parker Hannifin.
The use of desiccant breathers should not be limited to very large tanks. Any size storage vessel, down to barrels, can introduce contamination. Desiccant breathers are recommended for any storage vessel equipped with a breather vent.

4.0 Benefits
Many dealer facilities with modern bulk fluid handling have incorporated desiccant breather filters. The actual incremental benefit is difficult to measure without a baseline of moisture and particulate contamination before the desiccant filtration was installed. However, if stored fluid is found to be contaminated with dirt or moisture, the presence of properly working desiccant breathers indicates the contamination was present in the fluid before delivery.
Operations that have endorsed the usage of desiccant breathers:
• Finning Chile Antofagasta Component Rebuild Center
• Finning Argentina – Alumbrera Mine
• Ferryros Peru – Yanococha Mine
• Western States Equipment – Simplot Smoky Canyon Mine

5.0 Resources Required
Initial installation or fitting of filters to existing vent pipes typically runs from $100 - $500 US. Cost of replacement filters range from $30 for small filters used on barrels and small tanks up to $800 for very large filters used on large bulk storage tanks.

6.0 Supporting Attachments / References
None

7.0 Related Best Practices
0806-2.1-1000 - Fluid Cleanliness Management
0806-2.1-1002 - Off-Board Machine Filtration
0806-2.1-1004 - Breather Filters
0806-2.1-1005 - Bulk Oil Filtration
0806-2.1-1006 - Bulk Fuel Filtration

8.0 Acknowledgments
This Best Practice was written by:
Richard Douglas
CGM Product Support
Douglas_richard_d@cat.com
(309 675-5699
Other contributors include:
Dave Baumann
MPSD Contamination Control
Baumann_david_l@cat.com
(309) 675-6849
Carmen Rose
MPSD Contamination Control
Rose_carmen_l@cat.com
(309) 675-8074
Kiwi Haig
CGM LACD Product Support
Haig_kevin@cat.com
+56 55 200947

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Measuring Oil Cleanliness

1.0 Introduction
Maximizing component life requires maintaining high levels of fluid cleanliness. The ability to effectively and consistently measure debris in fluids is a key element in catching failures before they occur. Laser particle counters are used to measure the amount of debris in oil. These units may be permanent installations in an oil analysis lab or portable units for field use.
Lab units are more repeatable and have less variability, but transportation to a lab and processing could take up to two days.
Portable units provide real-time information at the mine site but are more variable due to instrument quality and operator variability of how samples are processed. Both approaches have benefit and drawbacks.

2.0 Best Practice Description
Closely monitoring and tracking particle count data for each compartment is an effective way to manage fluid cleanliness and component performance. Particle counts before and after PM service help to identify the following;

2.1 Cleanliness at the Start of the PM Period
Compartment oil cleanliness after PM service, off-board filtration, etc. at the beginning of the PM interval.

2.2 Cleanliness at the End of the PM Period
Compartment oil cleanliness at the end of the PM interval prior to PM service. This indicates if the on-board filtration is capable of keeping the oil clean.

2.3 Break-In Period Completion
If end of PM readings exceed ISO 18/15, off-board filtration is recommended during PM to remove excess contamination. If oil cleanliness is ISO 18/15 or better, the filters are capable of maintaining fluid cleanliness and off-board filtration is not required.

2.4 Component Failure In Progress
After the break-in period is complete, particle counts will usually stabilize to +/- 1 ISO code range (due to measurement variability). If particle increase is more than the normal range of variability, a failure may be in progress. Failures almost always generate large amounts of debris that can usually be detected by particle count. SOS sample data should be used to verify if a failure is in progress.

3.0 Implementation Steps

3.1 Oil Analysis Lab
If an oil analysis lab is close, it is the lower cost option for particle count measurements. Some dealers and customers use portable counters for immediate results and oil analysis at PM or if the portable counter indicates a problem.

3.2 Portable Particle Counters
Portable counters are expensive, costing $10,000 or more per unit. However, they are rapidly gaining acceptance due to their convenience and real-time feedback. Particle counters are available with a variety of functions, including data recording.

3.3 Data Management
Looking at row after row of particle count numbers can be mind numbing. If particle count is to be used as a tool, it must be displayed in a manner which permits easy visual assessment of trends and abnormal increases. Particle count data for each compartment of each machine can be tracked using the attached software.

3.4 Develop New Wear Material Trends
If replacing standard filtration with HE or UHE filtration, more debris will be captured and wear materials in the oil will increase at a much slower rate. New trends will be much lower than traditional level. New trends will need to be developed based on the performance with the improved filtration.

4.0 Benefits
1. Trending particle data for all particles provides an easy-to-use and convenient tool to monitor component health. If particle count raises sharply, an SOS sample can be used to determine the specific wear metal showing elevated levels.
2. Lower levels of contaminants extend the duration of failures in progress and allow more time to schedule repairs before a catastrophic failure occurs.
3. Portable counters allow real time multiple samples from all machine compartments, as well as new bulk fuel and bulk oils.

5.0 Resources Required
• Oil analysis lab or portable particle counter
• Access software program that allows input of particle count data, stores information in tables and provides output reports.
o Developed and shared by Griff Jones (Unatrac).
o Obtained through Jeff Wolffe, EAME Mining Rep. Wolffe_Jeffrey_S@cat.com
(Available mid-July 2006)
• Advice on particle counter selection features and use available from Caterpillar Marketing & Product Support Division Contamination Control Group.
o Contact Dave Baumann, Baumann_David_L@cat.com or Carmen Rose. Rose_Carmen_L@cat.com

6.0 Supporting Attachments
Component Life Management Master Document PDF file. (Click on Attachments within this document to view/open file)

7.0 Related Best Practices
0806-2.10-1000 -Managing Fluid Cleanliness

8.0 Acknowledgements
This Measuring Oil Cleanliness Best Practice was authored by:
Dick Douglas
Market Consultant
Caterpillar Global Mining
Douglas_Richard_D@cat.com
1-309-675-5699

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Managing Fluid Cleanliness

1.0 Introduction

This Best Practice provides an overview of the importance of maintaining clean fluids and offers suggestions on how best to achieve that. Detailed information can be found in the specific Best Practice publications cited.

Minimizing machine operating cost is critical to minimizing cost-per-ton. Aside from the cost of tires, fuel, and operator, about 70% of total machine operating cost is the life cycle costs of machine powertrain components. On a typical large mining truck, the cost distribution is as follows:

- Engine 40%

- Transmission & Torque Converter 10%

- Final Drive & Differential 40%

- Miscellaneous 10%

Component life cycle cost is roughly defined as cost to rebuild the component divided by actual component life in hours. Example:

($100,000 rebuild cost ÷ 10,000 hour life = $10 hour life cycle cost)

Extending the life of a component is the most important factor in reducing its life cycle cost. This does not mean simply extending overhaul intervals and allowing components to wear more severely. It means implementing a strategy to reduce the rate of wear and achieve longer

component life without incurring excessive wear.

2.0 Best Practice Description

The best way to minimize power train cost per hour is to extend component life and utilize the value built into the component. The most effective way to accomplish this is to operate the component with very clean oil throughout its entire life.

Fluid cleanliness management is a strategy to:

• Remove component and/or system break-in debris as quickly as possible on new and rebuilt components.

• Maintain very clean oil in the component and/or system throughout the entire PM interval and entire component life.

3.0 Implementation Steps

3.1 Dealer & Customer Commitment

3.1.1 Understand the Causes of Component Wear and Failure

• Reference Improving Component Durability booklets

(See Section 6.0 Supporting Attachments)

• Tolerate Early-Hour Filter Plugging

• Use Off-Board Filtration to Remove Break-In Debris

3.2 Bulk Fuel Filtration

For a variety of unavoidable reasons, fuel delivered to mine sites is usually contaminated with dirt and water. Because fuel is a very low margin commodity, suppliers almost never provide adequate bulk fuel filtration or exercise recommended storage practices. As a result, mines receive and use contaminated fuel, resulting in premature injector failure and wear out. This results in excessive fuel consumption and often results in mid-life injector set replacement.

The fuel filters on the machine are designed to provide final filtration for moderately clean supply fuel. Machine filtration is not intended to clean fuel contaminated with large amounts of dirt and water. If contaminated fuel is used, the capability of the onboard filtration is overwhelmed and injectors either wear out prematurely or seize.

Bulk fuel filtration has been used in the aviation industry for more than 50 years to address the same problems. Caterpillar has now adopted this proven technology to help mining customers clean contaminated fuel.

Bulk fuel filtration consists of high capacity filters, which remove both excess dirt and water from the supply fuel before it is put into the machine.

Caterpillar has engineered a packaged system to remove both dirt and water. It requires very little maintenance and contains safeguards to prevent contaminated fuel from passing through the unit. The unit is self-contained on a skid and is located between the fuel storage tank and fueling station. It provides single pass filtration, and is offered in four sizes depending on the maximum flow rate of the fuel delivery system.

3.3 Bulk Oil Filtration

A widespread misconception is that new oil is automatically clean because of its appearance. In fact, nearly all new oil is contaminated to some degree with dirt, metal particles, plastic, water, or other foreign debris. These contaminants are introduced in the transportation and storage process from the time the oil leaves the refinery until it is used by the end-user.

Very little new bulk oil meets the recommended Caterpillar cleanliness spec for new oil of ISO16/13. This includes oil delivered in bulk tanks, steel barrels, plastic cubes, and small plastic containers.

Unfiltered new oil should never be taken directly from the container and placed into the machine.

This is true whether the oil is being used for refilling a compartment at an oil change interval or simply topping off a system.

A variety of bulk oil filtration methods are available and the best one for each situation is dictated by factors such as: volume of oil used, location, available infrastructure, and cost.

3.4 Off-Board Machine Fluid Filtration

Filtration carts can make a major contribution to extending component life. Many mines and Caterpillar dealers use filtration carts for the major systems during normal preventive maintenance. Carts are connected to major systems (rear axle, transmission, hydraulics, steering) and operate unattended while PM services are completed.

3.5 On-Board Machine Fluid Filtration

The micron rating of filters on many mining machine systems are sized so as not to plug during the initial break-in period on new machines. This does not provide optimal filtration capability to maintain very high levels of oil cleanliness after the break-in period is complete.

The most aggressive approach to removing break-in debris as quickly as possible and maintaining the highest level of fluid cleanliness is to use Ultra-High Efficiency (UHE) 6-micron filters in place of standard filters for all machine systems except the engine. Because these filters effectively trap very small particles, some filter plugging will occur during the initial PM periods.

3.6 Breather Filters

Dust entering fluid compartments through inefficient breather filters is often a source of fluid contamination. This can be easily prevented with the use of spin-on High Efficiency 4-micron fuel filters as breathers for all compartments. When used as fuel tank breathers, HE filters have reduced or eliminated premature fuel filter plugging in extremely dusty applications. HE fuel filters are also larger than standard breathers and have much greater capacity.

3.7 Measuring Oil Cleanliness

Component life is maximized when high levels of fluid cleanliness are maintained. The ability to effectively and consistently measure debris in fluids is a basic requirement of managing fluid cleanliness. Tracking fluid particle data is one way to monitor component health. If a particle count raises sharply, an SOS sample can be used to determine the specific wear metal showing elevated levels.

4.0 Benefits

Improved Durability

-Up to 1/3 longer life of powertrain and implement hydraulic components

-Does not apply to engine due to soot in lube oil.

Improved Reliability

-Reduce or eliminate repairs caused by contamination debris.

Improved Parts Reusability

-Reduced wear rates of internal parts improve reusability.

5.0 Resources Required

• Bulk Fuel Filter Coalescer

• Bulk Oil Filtration

o Permanent filtration installation (or)

o Portable filtration carts (or)

o Barrels (or)

o Cubes (or)

o On-Machine (or)

o Off-Board Filtration Carts

• Portable Particle Counters

• Particle Count Data Management Software

• Improving Component Durability Training Booklets

6.0 Supporting Attachments

See Component Life Management Strategy Document (Click on Attachments tab within this document to view attached file)

Improving Component Durability booklets

7.0 Related Best Practices

0808-2.10-1006 -Bulk Fuel Filtration

0808-2.10-1005 -Bulk Oil Filtration

0808-2.10-1002 -Off-board Fluid Filtration

0808-2.10-1002 -On-board Fluid Filtration

0808-2.10-1004 -Breather Filters

0808-2.10-1001 -Measuring Oil Cleanliness

8.0 Acknowledgments

This Managing Fluid Cleanliness Best Practice was authored by:

Dick Douglas

Market Consultant

Caterpillar Global Mining

Douglas_Richard_D@cat.com

1-309-675-5699

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Bulk Fuel Filtration

1.0 Introduction

Modern fuel systems use electronic unit injectors which deliver precise amounts of fuel at pressures up to 25,000 psi, and control injection timing to within thousandths of a second. Electronic unit injectors control the performance and fuel economy of the engine and are expensive to replace when worn. A rough estimate of injector replacement cost with parts and labor is approximately $1,000 per cylinder. And, of course, there’s the cost of taking a machine out of production.
Injectors operated on clean fuel should last through engine overhaul. The fuel filters on the machine are designed to provide final filtration for moderately clean supply fuel. Machine filtration is not intended to clean fuel contaminated with large amounts of dirt and water. If contaminated fuel is used, the capability of the onboard filtration is overwhelmed and injectors either wear out prematurely or seize.
For a variety of unavoidable reasons, fuel delivered to mine sites is usually contaminated with dirt and water. Because fuel is a very low margin commodity, suppliers almost never provide adequate bulk fuel filtration or exercise recommended storage practices. As a result, customers receive and use contaminated fuel, resulting in premature injector failure and wear out. This causes excessive fuel consumption and often results in mid-life injector set replacement.
Bulk fuel filtration has been used in the aviation industry for more than 50 years to address the same problems. Caterpillar has now adopted this proven technology to help mining customers clean contaminated fuel.

2.0 Best Practice Description

Bulk fuel filtration consists of high capacity filters, which remove both excess dirt and water from the supply fuel before it is put into the machine.
Caterpillar has engineered a packaged system to remove both dirt and water. It requires very little maintenance and contains safeguards to prevent contaminated fuel from passing through the unit. The unit is self-contained on a skid and is located between the fuel storage tank and fueling station. It provides single pass filtration and is offered in four sizes depending on the maximum flow rate of the fuel delivery system.

2.1 Dirt (Particulate Filter)

4-micron, beta 200, full synthetic particulate filter elements remove dirt in a single pass. Filter change intervals of up to one month depending on the level of fuel contamination.

2.2 Water (Coalescing Filter)

Coalescer unit contains multiple elements capable of removing up to 3% water by volume to 1,000 ppm (0.1%) or less at the rated flow. Water is automatically drained, requiring no manual intervention. Coalescing elements do not plug and usually require changing only once a year.

2.3 Flow Control Valve

An automated flow control valve slows down or stops fuel outlet flow if particulate filters plug or there are massive amounts of water in the fuel. This assures only clean fuel leaves the unit.

3.0 Implementation Steps

Technical information and pricing on these units is available from Cat Global Mining and the Cat Filters and Fluids group. Unit sizing is determined by the maximum flow rate of the fuel delivery system. Four different sizes are available:
50 &100 GPM
Small units intended for remote day tank applications or for portable use on a fuel truck where fueling is done manually.
200 GPM
Intended for fuel stations using fast-fill where maximum flow does not exceed 200 gpm. This unit will handle trucks through 793.
300 GPM
Intended for fast-fill of 797 trucks where fuel flow rates exceed 200 gpm.

4.0 Benefits

Supplying clean fuel to the machine permits the onboard fuel filters to function properly without plugging.
Most injectors should last to engine overhaul and provide improved long-term fuel economy and engine performance.

5.0 Resources Required

Permanent installation requires only a small concrete pad downstream of the bulk storage tank and supply pump. The unit is installed in series in the fuel supply line to the fueling station.
A water container is required nearby to store the waste-water removed from the fuel. No electrical power is required for the unit unless it is used in freezing climates.
An optional electric heating element is available to prevent water from freezing in the bottom of the coalescer tank.

6.0 Supporting Attachments

Component Life Management Master Document, PDF file. (Click on Attachments within this document to view)
An explanation of how the unit works, along with visuals is available in the “Managing Fluid Cleanliness” booklet form SEBF1020.

7.0 Related Best Practices
0806-2.10-1005 -Bulk Oil Filtration
0806-2.10-1000 -Managing Fluid Cleanliness

8.0 Acknowledgments
This Bulk Fuel Filtration Best Practice was authored by:
Dick Douglas
Market Consultant
Caterpillar Global Mining
Douglas_Richard_D@cat.com
1-309-675-5699

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