Expansion tank VAREM R1008228 8 L for potable water systems

VAREM expansion tank R1008228 with an 8 L capacity is a diaphragm-type vessel designed for potable water systems. It provides pressure buffering and absorbs thermal expansion in domestic and light commercial hot and cold water installations. The tank separates the water from an internal air cushion by a flexible diaphragm, helping to stabilise system pressure, reduce pump cycling and protect valves, fittings and pipes from pressure surges.

Advantages

The compact 8 L volume and diaphragm design ensure consistent pressure control without waterlogging. The air-water separation prevents corrosion of the internal shell and maintains reliable performance over time. Because it is intended for potable water use, materials and construction meet requirements for use in drinking water systems, allowing direct integration with hot or cold circuits. The tank’s simple installation profile minimises space requirements and maintenance interventions.

Suitable for

• Domestic cold and hot potable water systems
• Small commercial water installations and service loops
• Pressure boost and circulation systems to reduce pump on/off cycling
• Systems requiring compensation for thermal expansion

Key specifications

• Type: Diaphragm expansion tank for potable water
• Nominal capacity: 8 litres
• Function: Pressure buffering and thermal expansion compensation
• Connection: Standard plumbing connection for domestic water circuits
• Suitable media: Drinking water (hot and cold)

How to use

Install the expansion tank on the pressure side of the system according to local plumbing practice and the system manufacturer’s instructions. Ensure the tank is mounted in a stable position and connected with appropriate fittings and isolation valves to allow service and replacement. Adjust the precharge pressure of the air side to match the static system pressure before filling the circuit; this helps to ensure correct diaphragm operation and to avoid premature cycling of the pump. Verify that all connections are watertight and that the system is vented of air after filling.

Usage recommendations

Periodically check the tank’s precharge pressure and inspect for leaks or signs of loss of diaphragm function. For systems with variable operating pressures, set the precharge slightly below the minimum system pressure and follow manufacturer guidance for maintenance intervals. Replace the tank if the diaphragm shows irreversible failure or if you notice frequent pump cycling that cannot be resolved by pressure adjustment.