FLEXCON PH5 2 GAL FLEX 2 PRO POTABLE WATER WELL / THERMAL EXPANSION VFD PRESSURE TANK USE AS A WATER WELL CONSTANT PRESSURE VFD TANK OR USE AS A HEATING SYSTEM EXPANSION TANK DRAWDOWN @ 30-50 setting : 0.7 gallons DRAWDOWN @ 40-60 setting : 0.6 gallons Factory pre-charged pressure: 40 PSI; Tank volume: 2 gallons