Water Ballasting / Magnesium Chloride

Principle

The inner tubes for tractor drive wheels are equipped with valves suitable for both air and water flow. Filling the tyres with water requires the use of a special auxiliary filling device.

75% Water Fill

The tyre retains approximately the same flexibility as when filled with air only, as the remaining volume (25%) is filled with air at the pressure specified for the tyre size and load.

Antifreeze Agents: Calcium Chloride or Magnesium Chloride

For tractors operating in cold climates, freezing of the filling water must be prevented. This is achieved by adding calcium chloride (CaCl₂), which does not attack either natural or synthetic rubber. The calcium chloride is added to the water (not the other way around) contained in a galvanized vessel. The mixture must be stirred thoroughly to obtain a proper solution. The table below specifies the required quantities of calcium chloride for each tyre size with a 75% water fill. The specific gravity of the solution that protects the tyre against freezing down to −30 °C is 1.2 g/cm³ (approximately 45 kg CaCl₂ per 100 litres of water).

When using magnesium chloride (MgCl₂) as an antifreeze agent, a mixing ratio of approximately 55 kg MgCl₂ per 100 litres of water is required for the same temperature range. In this case, the increase in weight is reduced by about 10% compared with the use of CaCl₂.

Weight Increase Due to Water Ballasting