Abstract: A device for the saturation of liquids with gases is described and makes it possible to compensate for temperature-dependent changes in the length of the string of the aerating device without affecting its intactness. The device includes an air conduit connected to coaxially arranged and tightly held together aerating modules each of which has a perforated tubular air distributor coaxially encompassed with a tubular dispersing element. The air distributor of at least one module is sectional as for length and is made up of three coaxial components. A central component of the three components is in fact a tubular perforated element having its ends extended, with a possibility of sliding reciprocatingly, in the respective ends of extreme components. The dispersing element of the module overlaps at least partially the zone of interconnection of the sectional air distributor.