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Expansion vessels



Expansion vessels preloaded with replaceable membranes suitable for solar energy installations.
Manufactured according European Directive 97/23/CE for pressure vessels, two dish ends and curved metal sheet joined by welding process and procedures by homologated staff. Models  DP/VS y DP/VSV, are manufactured, tested, checked and verified by Mecalia.

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ApplicationsReplaceable membrane EPDM. - Working temperature : -10ºC.On heating installations when water is heated , his volume increase, this can be a dangerous fact. Expansion vessel are conceived and designed to compensate the variation on volume of water caused


Working Pressure: 8 bar
Max. Working Temp.: -10ºC up to +140ºC
Membrane: EPDM Replaceable
Marked: CE according Directive PED 97/23/CE.
Composition: Galvanized steel flange with internal polypropylene protection in the area in ​​contact with water.
Mixing: Water/glicol at 50%.
Colour: White RAL 9010.
Operation: There is a full air chamber under pressure between the membrane and the tank plate. Once connected the expansion vessel to the circuit to which is intended, the temperature rises and also does the volume of water (image 1) When membrane is filled with water, the air is pushed and compressed. The water volume keeps expanding until maximum working temperature is reached. At this state, the membrane occupies almost all the space of the tank (image 2). Once the effort stops, the temperature of the installation goes down gradually and also the water volume. The water starts to come our of the tank due to the pressure of air found in the pressurized chamber. The air pushes the membrane till it gets the original pressure back. Finally, when the vessel reaches initial position, a new cycle begins (image 3). At the moment of setting up the vessel in a solar installation, the following points must be kept in mind: * Before proceeding to the installation, make sure that the expansion vessel volume has been calculated by proffesional staff. * The expansion vessel will be placed in the return piping of solar installation, as far as possible from the solar collector. * The expansion vessel will be installed in such a way that airbeds cannot be produced. * Avoid radiations near the expansion vessel to protect membrane against the possible increase of temperature. * It is not allowed any valve that could be closed and insulate the circuit of the expansion vessel. * Fit the inflating pressure of the vessel to the network pressure (PINFLATING=PNETWORK+0,2 bar)
Maintenance: Maintenance must be carried out exclusively by authorized staff. At least once every six months, check through the inflating valve that pressure is correct, with the precaution of doing so by contrasting values ​​at the same temperature and with the installation depressurized. Never disassemble the vessel without having previously depressurized the installation. Standard pressure should be regular and adjusted according installation. Protect the vessel from weather inclemences.
Advantages: Water hammer decrease. Reduction of the consumption of water and electrical energy, due to the safety group, avoiding water leaks.