Other Line Systems

In addition to fuel lines and air brake lines, VESTAMID® compounds are also used to produce other air and liquid-conveying lines. Depending on its function and the environment in which it occurs, each application emphasizes different properties, so we adapt our compounds to meet specific, individual requirements.

• For the clutch line system, we offer flexible VESTAMID® L compounds with particularly high resistance to engine oil, aggressive chemicals, and hydraulic fluids. Their low water absorption trough diffusion ensures that the function of the hydraulic fluid is not impaired. Due to their good resistance to heat aging, the lines are suitable for use at elevated temperatures in the engine compartment. Compatible polyamide 12 connectors, obtained by direct injection molding, provide a seamless connection with a high degree of security against pressure and leakage. Clutch line systems made entirely of VESTAMID® consist of fewer components than the conventional metal-elastomer systems and are therefore lighter in weight and more advantageously priced.
• Vacuum brake booster lines are exposed to temperatures up to approximately 150°C. They are placed between the brake booster and the engine, and they must have the necessary flexibility and low-temperature impact strength. In addition to generally good resistance to attack by chemicals and the ability to withstand stress cracking by air-gas mixtures, both internally and externally, good resistance to ozone is important—conditions that VESTAMID® L compounds are custom-tailored to satisfy entirely.
• Steel tubes for hydraulic brake systems in passenger cars and light utility vehicles are fitted, for better corrosion protection, with a 0.15 mm thick extrusion coating of VESTAMID® L. This must, of course, adhere well to the metal and possess good low-temperature impact strength against stone impacts, not to mention feature good chemical resistance to de-icing salt and salt-spray.
• Lines for windshield washer systems convey water-ethanol mixtures containing cleaning agents. The lines should be able to tolerate these fluids. Moreover they must be flexible and easily installable, and most importantly, they should not kink. EPDM tubes are still widely used for this purpose, despite the fact that plastic lines offer certain advantages. Other things being equal, corrugated tubes of VESTAMID® E with quick connectors are denser, more durable, and more inexpensive to install. Because of the increased aggressiveness of windscreen washing liquids as a result of the change from isopropanol to ethanol, we also offer VESTAMID® D compounds developed specially for this application.
• EPDM tubing has again been traditionally used in coolant circulation. Here again monotubes made of VESTAMID® L or VESTAMID® D are preferred on grounds of price, weight and assembly because they are easily installed with quick connectors, for example, in the case of vent lines between the cooling water overflow reservoir and the radiator. If the requirements for temperature and pressure resistance are more stringent as regards contact with the coolant, multilayer tubing made from VESTAMID® L with an internal layer of DYFLOR® or polyolefins is used. Larger tube diameters are also available for this purpose.
• To support engine performance, tubes located near the engine block have to supply air or air-gas mixtures. To supply air, VESTAMID® L tubes are invariably used if other polyamides fail to have the requisite flexibility, low-temperature impact strength, and heat aging resistance.
• A feature that has long been widely used in utility vehicles is now being increasingly offered by manufacturers in passenger vehicles to increase comfort and safety: electronically controlled balancing of the vehicle on the road by means of an air suspension system. We have adapted the VESTAMID® L tube and connector system, already proven in trucks, to the requirements of passenger cars: standard compounds for flexible air suspension lines that are resistant to pressure and zinc chloride and that feature low-temperature impact.
• Good chemical resistance is required for plastics of clips holding various pipes locate underneath car chassis. Zinc chloride in de-icing salt does not cause stress cracking in clips made of DAIAMID.