100 Liter / 26.4 Gallon Red Expansion Tank for Solar Water Heater Systems Thermal Pressure Protection

Duda Solar Expansion TanksRed / Solar Expansion TanksExpansion tanks are essential for solar water heater systems. The Red expansion tank is used for relieving pressure build-up in the closed loop system. This helps keep the pressure consistent and relieve pressure from the piping as the working fluid increases in temperature. Should the solar system go into overheat mode and shut down the circulation pump, the expansion tank is essential for preventing the pressure valve from blowing out the working fluid. The Red Duda Solar expansion tank is fitted with a special high temperature EPDM membrane made in Italy which can withstand the high temperatures of the solar systems.The size of the expansion tank needed depends on the total amount of fluid used in the closed loop (maximum possible volume). Some data regarding common fluid volumes in the solar systems is in the chart below.As an example, a standard 300 liter solar system has a 30 tube collector, 100 feet of 1/2 stainless steel tubing and a 300 liter tank (25m coil) for a total of ~7 liters of fluid volume, requiring at least an 8 Liter expansion tank.Tank SpecificationsDuda Solar expansion tanks come pre-charged with some air from the manufacturer. This charge can be increased or decreased with a typical inflation valve. This air charge should match the pressure at which you want the working fluid to begin entering into the expansion tank (usually just above the normal working pressure). As fluid pressure increases, some fluid enters into the tank, pushing the air back and thus rising the pressure of the air. Eventually, the tank will become nearly full with fluid or reach the maximum working pressure for both the fluid/air.