Cleaning Components with Carbon Dioxide (CO<SUB>2</SUB>) {0680, 1000, 7000} Caterpillar

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Introduction

© 2019 Caterpillar® All Rights Reserved. This guideline is for the use of Cat dealers only. Unauthorized use of this document or the proprietary processes therein without permission may be violation of intellectual property law.

Information contained in this document is considered Caterpillar: Confidential Yellow.

This Reuse and Salvage Guideline contains the necessary information to allow a dealer to establish a parts reusability program. Reuse and salvage information enables Caterpillar dealers and customers to benefit from cost reductions. Every effort has been made to provide the most current information that is known to Caterpillar. Continuing improvement and advancement of product design might have caused changes to your product which are not included in this publication. This Reuse and Salvage Guideline must be used with the latest technical information that is available from Caterpillar.

For technical questions when using this document, work with your Dealer Technical Communicator (TC).

To report suspected errors, inaccuracies, or suggestions regarding the document, submit a form for feedback in the Service Information System (SIS Web) interface.

Canceled Part Numbers and Replaced Part Numbers

This document may include canceled part numbers and replaced part numbers. Use NPR on SIS for information about canceled part numbers and replaced part numbers. NPR will provide the current part numbers for replaced parts.

Important Safety Information

Illustration 1	g02139237

Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools to perform these functions properly. Safety precautions and warnings are provided in this instruction and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive. If a tool, a procedure, a work method, or operating technique that is not recommended by Caterpillar is used, ensure that it is safe for you and for other people to use. Ensure that the product will not be damaged or the product will not be made unsafe by the operation, lubrication, maintenance, or the repair procedures that are used.

Safety precautions and warnings are provided in this manual and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons.

The hazards are identified by the safety alert symbol which is followed by a signal word such as danger, warning, or caution. The "WARNING" safety alert symbol is shown below.

Illustration 2	g00008666

This safety alert symbol means:

Pay attention!

Become alert!

Your safety is involved.

The message that appears under the safety alert symbol explains the hazard.

Operations that may cause product damage are identified by "NOTICE" labels on the product and in this publication.

Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. The safety information in this document and the safety information on the machine are not all inclusive. Determine that the tools, procedures, work methods, and operating techniques are safe. Determine that the operation, lubrication, maintenance, and repair procedures will not damage the machine. Also, you must determine that the operation, lubrication, maintenance, and repair procedures will not make the machine unsafe.

The information, the specifications, and the illustrations that exist in this guideline are based on information which was available at the time of publication. The specifications, torques, pressures, measurements, adjustments, illustrations, and other items can change at any time. These changes can affect the service that is given to the product. Obtain the complete, most current information before you start any job. Caterpillar dealers can supply the most current information.

Summary

Carbon Dioxide (CO₂) cleaning process removes micron and sub micron particles and hydrocarbon-based contamination. The CO₂ cleaning method has the following benefits:

• Waterless

• Chemical waste free

• Residue-free

• Non-corrosive

• Non-abrasive

• Non-conductive

• Uses no hazardous chemicals

• Reduces downtime

The cleaning process is based on the expansion of carbon dioxide through an orifice. This expansion leads to the formation of dry ice particles in a high velocity gas carrier stream. Upon impact with the dirty surface of the component to be cleaned, the dry ice media removes the contaminants/dirt. The smallest particles that have been removed were about 0.03 microns.

This cleaning process can be used for either the initial or the final cleaning of components.

Examples of equipment that would require off-site cleaning:

• Power generation applications

• Marine applications

• Other applications where the equipment could not be brought to the repair facility.

Do not perform any procedure, outlined in this publication, or order any parts until you read and understand the information contained within.

Service Letters and Technical Information Bulletins

Safety Requirements

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Personal injury or death can result from contact with liquefied Carbon Dioxide (CO2). Contact of liquefied CO2 with bare skin can result in frostbite. Keep all exposed skin away from contact with liquefied CO2 with the use of proper Personal Protection Equipment (PPE). Inhaling CO2 in high enough concentrations can cause asphyxiation. Work only in well-ventilated areas.

Adhere to the following list of safety rules to perform the procedure safely as outlined in this guideline.

1. Contact with CO₂ pellets on exposed skin should be avoided, as the low temperature, −80° C (−112° F), of the pellets can burn the skin and cause tissue injury. Never hold CO₂ pellets in your bare hands.

2. Never point the nozzle at a person and extreme caution is required whenever there are people near the jobsite. CO₂ pellets leaving the equipment may deflect within a 100 ft area of the nozzle.

3. Protective clothing should be worn while working. The clothing will consist of several layers, protect against the cold, and totally cover the body. The clothing should have no pockets or creases, in to prevent CO₂ pellets from falling into them. Ensure that you are wearing ear and eye protection and gloves protecting against the cold.

4. Never work in a closed room that is not ventilated appropriately. Depending on the circumstances outside and on the size of the room, carbon dioxide can quickly displace the oxygen from the atmosphere.

5. Never use the equipment without first having read the operating instructions. Should there be any questions, do not hesitate to contact the manufacturer of the equipment.

6. The equipment must never be used by untrained personnel.

7. Only use the equipment on those components that are to be cleaned.

8. Any other person who is situated within the operating range of the equipment should respect the safety and clothing rules as mentioned above.

9. Never store CO₂ pellets in a hermetically sealed receptacle.

10. Never store CO₂ pellets in a cavity, a cellar, or in a closed room.

11. Never mix CO₂ pellets into liquids.

Equipment

Preparations for use of the CO₂ cleaning equipment must be made according to the equipment manufacturer recommendations. There are many manufacturers of cleaning equipment available each with specific controls and procedures that must be followed in to get acceptable results. Illustration 3 shows a typical CO₂ cleaning system.

Illustration 3	g02800141
Typical CO2 cleaning system.

Description of Operation

Illustration 4	g06382006
CO2 Cleaning System Components

The CO₂ cleaning system begins with liquid CO₂ stored in a tank (1) at 1378 to 2067 kPa (200 to 300 psi) which is then transported through a hose under its own pressure to a pelletizing machine (2).

A rapid expansion of the liquid in the chamber converts the CO₂ to a solid state of dry ice or snow. The snow is compressed and extruded through a disk die into small pellets (3). Pellets are available in several sizes, ranging from 1.02 to 3.05 mm (0.040 to 0.120 inch) in diameter.

These pellets are then placed into the hopper (7) of the dry ice cleaning equipment, which feeds the pellets into the pellet distributor (8).

Air pressure is supplied by an air compressor (4) capable of supplied 289 to 1585 kPa (42 to 230 psi) of air pressure. The air pressure is routed through and optional air dryer (5) and the air pressure regulator (6) to the pellet distributor.

The pellets are transported from the pellet distributor via air pressure through a hose to the blasting nozzle or gun (10).

High-pressure air from the air compressor is routed through an air pressure regulator (9) to the gun. At the gun, the pellets are fed into the high-pressure air varying from 310 to 1723 kPa (45 to 250 psi) by the way of a venturi effect, and are propelled from the nozzle with a velocity of 75-3600 feet per second (11). Pellet velocity is a function of the air pressure selected for the application being performed.

Cleaning Procedure

Note: The procedure shown in this instruction was performed without disassembling the engine completely.

1. Remove any components necessary to gain access to the area that is to be cleaned. Refer to the appropriate Service Manual for the proper procedures.
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   Illustration 5	g06382007
   Pistons and cylinder bores to be cleaned.

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   Illustration 6	g02820616
   Close-up of piston prior to cleaning.

2. Ensure that all openings are covered or plugged in, to prevent debris contamination.

3. Follow the directions supplied in the CO₂ cleaning equipment owners manual for proper set-up and operation procedures.
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   Illustration 7	g02820657
   Cleaning the piston and cylinder bores.

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   Illustration 8	g02820661
   Cleaning the cylinder head assembly.

4. Carefully clean the component following all safety precautions outlined in this guideline and the CO₂ cleaning equipment owners manual.
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   Illustration 9	g02821343
   Pistons and cylinder bores after cleaning.

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   Illustration 10	g02821418
   Close-up of piston after cleaning.

5. Inspect the area cleaned to determine if further cleaning is required.

6. Follow the shutdown and storage procedures outlined in the CO₂ cleaning equipment owners manual.

7. Refer to the appropriate Service Manual for the proper procedure to reinstall all removed components.

CO₂ Cleaning Equipment Suppliers