Vertrel Solvents - Case Studies

Aircraft wheel and brake assemblies undergo high mechanical and thermal stresses. During an aircraft landing, extraordinary quantities of kinetic energy is transformed first into heat from the braking system while carrying the mechanical stress of the aircraft and its cargo. The brake heat pack assembly subsequently transfers this thermal load to surrounding elements, including the wheel, tire and brake components.

Further stress occurs while in flight. The hot wheel assemblies quickly are subjected to extremely cold temperatures at high altitudes. Due to the potential for generating ice crystals, entrapment of moisture in the wheel assemblies is a primary concern.

Cleaning and subsequent lubrication of these parts is critical to safe operation. Vertrel^® MCA has been used successfully in the cleaning of the wheel assemblies as part of a continual preventive maintenance program to maintain highly reliable operation.

Items to be cleaned included:

The cleaning process for landing gear assemblies and their component parts uses a standard two sump vapor degreaser. The process consists of an immersion in the boil sump, followed by a spray, followed by a rinse sump immersion, then drying. This process removes contaminants from the intricate parts and from hard-to-access locations.

The initial immersion in the boil sump removes the majority of the soil. Spraying with pure solvent vapor distillate further removes contaminants from component surfaces. Components then are rinsed using ultrasonic energy to remove any fine particulates.

After removal from the rinse sump, the parts are held in the vapor zone. There, the parts equilibrate to the temperature of the solvent vapor, condensation ceases, and the parts are clean, dry and safe to handle.

Typical materials and surfaces cleaned included aluminum, steel, titanium and various gaskets for the hydraulic systems.

Typical contamination removed included grease, hydrocarbon oils, Krytox^® dry lubricants, water with a wide variety of contaminants, and various particulates including tarmac from the runways.

Typical cycle times are less than eight minutes per batch of parts.

Low residues
Excellent solvent penetration
Fast and thorough drying
Easily recycled
Chemically stable
Environmentally preferred
Low (good) toxicity

Moisture entrapment
Low grease-cutting capability
Long soak times for cleaning
Low penetration for complex parts
Long drying time
Large potential for rust
High energy consumption

Trichloroethylene --

Hazardous composition
Extensive venting required
Banned in some regions due to high photochemical reactivity
High disposal costs


About \| News
	Aircraft Maker uses Vertrel® to Clean Aircraft Landing Gear
		Synopsis Because of superior cleaning results, toxicity ratings and materials compatibility, Vertrel^® MCA was selected by a major aircraft manufacturer as a replacement for trichloroethylene for the degreasing of landing gear components. Background Aircraft wheel and brake assemblies undergo high mechanical and thermal stresses. During an aircraft landing, extraordinary quantities of kinetic energy is transformed first into heat from the braking system while carrying the mechanical stress of the aircraft and its cargo. The brake heat pack assembly subsequently transfers this thermal load to surrounding elements, including the wheel, tire and brake components. Further stress occurs while in flight. The hot wheel assemblies quickly are subjected to extremely cold temperatures at high altitudes. Due to the potential for generating ice crystals, entrapment of moisture in the wheel assemblies is a primary concern. Cleaning and subsequent lubrication of these parts is critical to safe operation. Vertrel^® MCA has been used successfully in the cleaning of the wheel assemblies as part of a continual preventive maintenance program to maintain highly reliable operation. Items to be cleaned included: Wheel bearings Bearing seals Heat shields Retaining pins and rings Bushings Valves Cleaning with Vapor Degreaser The cleaning process for landing gear assemblies and their component parts uses a standard two sump vapor degreaser. The process consists of an immersion in the boil sump, followed by a spray, followed by a rinse sump immersion, then drying. This process removes contaminants from the intricate parts and from hard-to-access locations. The initial immersion in the boil sump removes the majority of the soil. Spraying with pure solvent vapor distillate further removes contaminants from component surfaces. Components then are rinsed using ultrasonic energy to remove any fine particulates. After removal from the rinse sump, the parts are held in the vapor zone. There, the parts equilibrate to the temperature of the solvent vapor, condensation ceases, and the parts are clean, dry and safe to handle. Typical materials and surfaces cleaned included aluminum, steel, titanium and various gaskets for the hydraulic systems. Typical contamination removed included grease, hydrocarbon oils, Krytox^® dry lubricants, water with a wide variety of contaminants, and various particulates including tarmac from the runways. Typical cycle times are less than eight minutes per batch of parts. Major Advantages of Vertrel^® MCA Low residues Excellent solvent penetration Fast and thorough drying Easily recycled Chemically stable Environmentally preferred Low (good) toxicity Disadvantages of Other Cleaning Systems Aqueous wash -- Moisture entrapment Low grease-cutting capability Long soak times for cleaning Low penetration for complex parts Long drying time Large potential for rust High energy consumption Trichloroethylene -- Hazardous composition Extensive venting required Banned in some regions due to high photochemical reactivity High disposal costs


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