X5S is a liquid alkaline formulation, suitable to be used with hard waters, for the recovery cleaning of closed lines subject to heat exchange in the food and dairy industry. X5S is able to easily remove organic and inorganic residues from surfaces, while the presence of controllers of the water hardness enables to work also with waters with a high content of salts. The formulation enables to postpone over time the acid descaling stage. The absence of surfactants enables to reduce the polluting charge which goes to the drains. X5S is particularly suitable for the single phase washings where a conductimetric automatic control is necessary.