PRELOAD ADJUSTMENT COOLING AND HEATING CLOSED SYSTEMS EXPANSION VESSELS
Adjustment of inflation pressure:
In order to ensure the correct operation of the expansion vessel, it is necessary to check and adjust the inflation pressure, both at the time of installation and at regular maintenance.
In cases where the expansion vessel is placed on the drive side of the system, the pressure differential of the circulation pump shall be taken into account when obtaining P0 and prevent the appearance of vacuum at the top of the heating system.
Pv: Not used in refrigeration
Installation water filling :
Pini initial pressure obtention. It is one of the values that can most influence in the optimal functioning of the expansion vessel. Indicates the lowest pressure in the operating range of the heating system. It is recommended for diaphragm expansion vessels to adjust the Pini value at least 0,3 Bar above the predefined P0 gas pressure. In addition, Pini shall be adjusted so that the pressure measured at any point in the heating system is always higher than 0,5 Bar. To do this, the circuit is slowly filled with cold water, purging the inside contained air through the points provided for it. The initial pressure at the height of the expansion vessel shall exceed the inflation pressure P0 of the expansion vessel by 0,3 Bar.
Installation water re-filling:
When setting the highest pressure in the operating range of the Pfin heating system, this value should not be higher than the safety valve adjustment pressure PSV minus a difference in the closing overpressure, as indicated in standard EN12828.
To this end, the heating system is put into operation at the maximum working temperature, and the air is regularly purged. Pumps are turned off and purged. Fill the water circuit to the final pressure (Pfin).
For more information consult the instruction manual.