Wet strength agents are polymeric additives that enhance water resistance properties, especially in sanitary and specialty papers. They are applied in the paper machine via a size press or spraying device. Because of their high pH value, these substances are stored in double-walled GRP (glass reinforced plastic) tanks. The high viscosity of the medium requires the use of a pneumatic conveyor system and special eccentric pumps for filling and emptying. With these pump types, dry run protection and pressure monitoring is a necessity.