Expansion tank connection diagram

Expansion tank connection diagram to the heating system should include:

Shut-off valve - to disconnect the tank from the system and check the initial pressure in the gas chamber.

Drain valve - to drain water from the tank.

Pressure gauge for monitoring pressure at the point of connection of the expansion tank.

Safety valve - to protect the heating system from emergency overpressure.

Expansion tanks for heating systems are used in buildings with autonomous heat sources and in buildings connected to the heating network via an independent circuit.

The expansion tank is connected before the suction pipe of the circulation pump, and there should be no elements creating significant hydraulic resistance between the connection point of the tank and the pump. This connection scheme ensures stable excess pressure in the heating system, regardless of thermal and hydraulic conditions.

The connection is made using detachable joints, as it may be necessary to disconnect the tank for maintenance during operation.

Another feature of membrane expansion tanks is the increase in pressure in the heating system as the water temperature rises. Therefore, the tank must be designed so that at the maximum water temperature, the pressure does not exceed the maximum allowable, and at the minimum - it does not fall below the pressure required to fill the heating system. To avoid pressure fluctuations in the heating system due to temperature changes, an expansion tank with gas chamber pressure maintained by a compressor can be installed.

Boiler expansion tank is only needed if the boiler is connected to a closed heating system. It protects the boiler and the connected heating or hot water system from pressure exceeding the maximum allowable value. Low-power boilers (up to 30 kW) are usually factory-equipped with expansion tanks, while larger boilers require a separately selected expansion tank.

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