GEIGER Automotive has more than 20 years’ production experience and over twelve years’ development competence in this product segment – and is also the only supplier to manufacture these products using the hot gas welding method and can thus achieve a residual soiling level of less than one milligram. The company also excels with its high series production quality with minimum failure rate.

Field of application and function

• Coolant expansion tanks offer expansion volume for the thermal expansion of the coolant in the circuit.
• They remove gas bubbles from the coolant circuit and hence ensure the reliable flow and heat distribution in the system.
• Pressure hammers in the coolant system caused by dynamic effects such as an increase in speed of the water pump and switching of the different valves are attenuated by the tanks.
• Furthermore, they provide coolant as working volumes for dynamic effects (acceleration, inclined positions or expanded hoses due to pressure increases).
• Protect individual components against excessive pressure or vacuum in conjunction with the screw cap.
• Discharged coolant is diverted via the tanks into the engine compartment.
• Coolant expansion tanks warn the driver of coolant losses.

• The demands made on coolant expansion tanks are enormous. They have to withstand ambient temperatures between – 40° C and +125° C and coolant temperatures between – 40° C and max. +143° C.
• They can withstand pressures up to 2.5 bar.
• The leak tightness of the tanks has to be assured over the whole service life of the vehicle and at all temperatures and pressure changes.

Materials

• Standard materials are polypropylene (PP) and polyamide 66 (PA 66), PA 66 with 30 percent glass fibres; in addition, glass fibre-reinforced PP and PA with 15 percent glass fibre reinforcement are also employed.