Solar Expansion Vessel Pressure

Mab when we took the pressure of the expansion vessel as in air pressure when the fluid system was registering zero the vessel showed an air pressure of 2 bar.

Solar expansion vessel pressure. The expansion vessels are tested according to the pressure systems directive. The expansion vessel in a solar installation is placed on the pressure side of the circulation pump see figure 2. If you have a combi boiler you will have an expansion vessel. Calculating the expansion tank size vet through out the course of its life span a closed loop solar hot water system will get exposed to wide temperature changes.

As the liquid heats up and expands the pressure of the system increase to an amount greater than the air pressure inside the expansion vessel and causes the membrane to take up more liquid to the air side. Vapour in the expansion vessel itself is not wanted because the high temperature of the vapour damages the membrane. The diaphragm within the expansion vessel ensures that the system pressure does not exceed or go below the limits specified. But the expansion vessel was still empty of liquid and the corrugated pipe leading to the vessel was only warm for the first 6 inches from the system side.

Reduce the system pressure to zero. Zilmet and elbi are a popular producer of expansion vessels. Although we can pump them up with a foot pump it is likely that the vessel will deflate again if the pressure has been lost before. The solar expansion tanks has a rubber membrane which separates the solar liquid loop and the other side is filled with pressurized air.

This prevents vapour from entering the expansion vessel as much as possible. This vessel contains air and water from the central heating system and its purpose is to maintain the right level of pressure in the system. For more information on our range of stainless unvented cylinders visit w. Does any of you know the reason for this little fearure.

Expansion vessels also known as expansion tanks can be found in most domestic pressurised heating systems. Solar expansion vessels also known as expansion tanks are the most common source of failure in solar thermal solar water heating installations. If not re inflate but only check the vessel presure with the system presure showing zero on the gauge. Take a look at our step by step guide for checking and recharging external vessels.

All solar expansion vessels are suitable for installation in solar systems complying with din 4757 and en 12977 and are suitable for use with a mixture of water and propylene or ethylene glycol. To prevent the system from exceeding the pressure range allowed by the designer there s a need to park the fluid volume expansion. Then measure the presure oif the vessel should be about 0 7 bar for a normal 2 storey house.