Water Treatment > Quality Water Solutions > FAQ > What types of equipment should I use to store and transfer alum and PACl?

At a minimum, tanks should accommodate a liquid weighing 12 lb./gal and temperatures to 125 °F. Maintain liquid alum at 45 to 60 °F whether in indoor tanks, heated enclosures, or heated and insulated outdoor tanks. Materials that can be used with both coagulants include high-density polyethylene, fiberglass and fiberglass reinforced plastic. Do not use copper, zinc, aluminum, galvanized iron (black, mild, ductile, or low carbon), tin or lead with alum. Also avoid these materials when using PACl, as well as those made of stainless steel, brass or bronze.

Pumping system specifications are site specific and depend on user preference. Centrifugal transfer pumps work well for alum and most PACl products. Formulated coagulants, however, may be sensitive to the high velocities in centrifugal pumps and may need vane or progressive cavity pumps. Metering pumps can include diaphragm, piston, solenoid-operated diaphragm, progressive cavity and peristaltic types.

Schedule 80 PVC with socket connections is recommended for piping, provided it is adequately supported and the temperature remains below 120 °F. In order to adequately support piping above 120 °F, use Schedule 80 CPVC and Type 316 stainless steel for alum-based products and Alloy 20 and CPVC for PACl.