EEXPANSION VESSELS FOR HEATING
Preload expansion vessels with replaceable membrane for installation of heating closed circuits
Tanks made of steel according to the European Directory 97/23/CE for Pressure Units, made from two bottoms connected to each other through welding cords, following the procedures and with homologated staff.
All the expansion vessels of our DP/VR and DP/VRV types are manufactured, tested, checked and certified by our company.
APPLICATION:
Expansion vessels type DP/VR and DP/VRV are designed for heating installations which allows absorbing the volume rise caused by the rise of temperature of the heating fluid.
It can happen in a heating system when the water heating is produced, water dilates increasing in this way its volume, which can cause a dangerous situation for the installation. Expansion vessels are intended to compensate the variation of the volume of water due to the variation of the temperature in heating systems, avoiding the circuit to exceed the nominal pressure of its components. For example, the water heating up form 0ºC to 100 ºC increases its volume of about 4,5%. This means that there should be dimensioned a space inside the system that can keep the exceeding volume of water.
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, whit it, also the volume of water (see image 1)
When the membrane is filled with water, the air is pushed and it is compressed. The water volume keeps expanding until the maximum working temperature water is reached. At this state, the membrane occupies almost all the space of the tank (see image 2)
Once the effort stops, the temperature of the installation goes dawn gradually and also the water volume. The water starts to come out of the tank due to the pressure of the air found in the pressurized chamber. The air pushes the membrane till it gets the original pressure back. Finally, when the vessel reaches its initial position, a new cycle begins (see image 3).
At the moment of setting up the vessel in a heating installation, the following points must be borne in mind:
· Before proceeding to the installation, make sure that the expansion vessel volume has been calculated by the authorized staff.
· The expansion vessel will be placed preferably in the return piping in order to avoid the water temperature can damage the membrane. The expansion vessels will be compulsory assembled between the boiler and the mixing valve, preferably in the return piping to the boiler.
· For an installation of heating closed circuit, apart from the expansion vessel, a safety valve and a manometer must be compulsory set up. Safety valve will be perfectly rated according to the boiler pressure and the installation, and it will never exceed the maximum pressure of the vessel (with the monometer incorporated).
· The expansion vessel will be installed in such way that airbeds cannot be produced.
· Avoid radiations near the expansion vessel to protect membrane against the possible rises in temperature.
· No allow any valve that could be closed and insulate the own circuit of the expansion vessel.
· Fit the inflating pressure of the vessel to the network pressure.(P INFLATING= P NETWORK + 0,2 bar).
MAINTENANCE
- The maintenance must be done exclusively by authorized staff.
- At least once every six months, check through the inflating valve that the air chamber pressure is maintained in the correct values. Be careful of checking the contrast of values at the same temperature.
- Never disassemble the expansion vessel without having depressurized the installation previously.
-The standard pressure of the vessel must be regulated and fitted according to the function of the installation in which the vessel is installed.
- When the installation is filling with water, make sure the pressure indicated in the manometer exceeds slightly to the static pressure of the installation. Keep the installation at the maximal working temperature during half a day, eliminate the air of the system and replace it by water.
- Protect the expansion vessel from the inclemency of the weather.
- To prevent the expansion vessels from the inner rust is advisable to drain the closed circuit regularly.
TECNICHAL DATA
- Replaceable EPDM membrane.
- Working conditions: -10 ºC to 100 ºC
- CE marked according to Directory PED 97/23/CE.
- Galvanized steel flange with inner protection of polypropylene in the contact zone with the water.
- External finish colour RED RAL 3.000.
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