TSA Process Equipments Pvt. Ltd. Manufactures Softening Unit with Ion Exchange Resin. TSA Process Equipments Pvt. Ltd. Manufactures piping needs of the food, beverages and pharmaceutical industries. The Softening Unit with Ion Exchange Resin is also known as Base Exchange softening. The Softening Unit is the most common and probably the easiest method of removing hardness like calcium and magnesium from water and renders the water suitable for utility purpose. As the name implies ion exchange is a process in which undesirable ions are exchanged for more desirable ions.