30, 60, 100 Liter PE Reservoirs protect stored water quality Millipore's 30, 60, and 100 L polyethylene (PE) reservoirs are designed to provide effective protection against airborn contaminants. Stored Type 2 (analytical-grade) and Type 3 (laboratory-grade) water is used in various lab applications including glassware rinsing, microbiological media preparation, buffer preparation, equipment feed, manufacturing chemical and biochemical reagents.