Adjusting the pressure in the expansion vessel

Before connecting the expansion vessel to the water supply system, the initial pressure of the gas space must be created.

In an empty expansion vessel with a previously created pressure of the gas space Pг, the entire volume of the tank is filled with air (nitrogen gas).

After the pump is turned on, the system is filled with water and as soon as the water pressure exceeds the initial pressure of the gas space, the water, stretching the membrane and compressing the gas, enters the expansion vessel, and when the minimum working pressure Pmin for the water supply system is reached, it fills it by 10-15%.

A 15% water reserve in the expansion vessel tank is necessary to cover the water consumption during the time from the moment the pump is turned on until the water arrives from the pump to the water distribution valve. In the absence of a reserve, an unstable water consumption mode with interruptions is possible at the moment when all the water has been squeezed out of the expansion vessel, but the pump has not yet turned on.

How to create pressure in an expansion vessel tank

The initial pressure of the gas space is calculated for specific operating conditions. You can calculate the pressure in the expansion vessel in the [Calculations] section on our website. If the initial pressure of the gas space of the expansion vessel, set at the factory, exceeds the calculated value, it should be lowered by releasing the air, and if it is less, the pressure should be raised using a compressor.

The initial pressure of the gas space is accepted at 0.2 - 1 bar less than the pump turn-on pressure. The further the expansion vessel tank is installed from the point of maintaining constant pressure, the less gas pressure should be accepted initially.

The [Calculations] section provides a program that will help you determine all the parameters necessary for setting the pressure in the expansion vessel: the initial pressure of the gas space Pг, the turn-on pressure Pmin, and the turn-off pressure Pmax of the pump, for specific conditions.