8 Liter / 2.1 Gallon Blue Expansion Tank for Wells & Domestic Hot Water Supply Tank Thermal Pressure Protection

Duda Solar Expansion TanksBlue / Water Expansion TanksBlue Duda Solar Expansion tanks are constructed with a food grade EPDM diaphragm for potable water applications. These should be used for relieving pressure from building up in the domestic water tank as it heats from the solar loop. Use of an expansion tank helps regulate the pressure so that it does not get too high in the tank and cause water loss due to the T/P valve opening when the pressure of the water exceeds the limit.The difference in water density from cold (4°C) to near boiling (99°C) is approximately 4%. For maximum expansion capabilities, your expansion tank capacity should be 4% the size of your water heater. ie: A 300 liter tank should have a 12L expansion tank.Expansion tanks are also very useful in well pump applications. In order to avoid the pump turning off and on constantly, an expansion tank of adequate size should be placed in line to receive a hold water. When the tap is opened, the expansion tank will push out water using the pressure created by the air inside of it. The well pump will only need to turn back on when most of the expansion tank is empty and the water pressure has dropped below the minimum pressure threshold.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.