Expansion vessel for heating Reflex 12 l, diaphragm pressure tank for central heating systems

Expansion vessel Reflex 12 l is a diaphragm-type pressure tank designed for central heating systems. With a 12‑litre working volume, the vessel absorbs thermal expansion of water, stabilizes system pressure and reduces stress on boilers, radiators and piping. Its compact cylindrical design and pre-charged air chamber maintain hydraulic balance and help reduce pump cycling in residential and small commercial installations.

Advantages

The diaphragm design separates the air cushion from the water, preventing air dissolution and maintaining consistent pressure control over time. The 12‑litre capacity is suitable for small to medium closed-loop heating circuits and helps protect components from overpressure. Installation is straightforward thanks to standard connection dimensions and an accessible air valve for easy pre‑charge and maintenance.

Suitable for

• Residential central heating systems
• Small commercial heating installations
• Boiler protection against pressure spikes
• Hydraulic stabilization of closed-loop heating circuits

Key specifications

• Type: diaphragm (membrane) expansion vessel
• Nominal volume: 12 litres
• Function: absorb thermal expansion and maintain system pressure
• Mounting: compact cylindrical body for wall or floor-adjacent installation
• Air pre-charge: accessible valve for pressure adjustment and maintenance
• Connection: standard heating system connection dimensions suitable for domestic plumbing

How to use

Install the expansion vessel in a dry, accessible location near the boiler or main manifold, following local regulations and the heating system designer's instructions. Ensure the vessel is oriented according to the manufacturer's guidelines and connect it to the heating circuit using appropriate fittings. Before commissioning, check and, if necessary, adjust the pre-charge air pressure to the value recommended for the specific system (typically slightly below the system's static pressure). After filling and purging the heating circuit, recheck the vessel pressure and system pressure to confirm correct operation.

Usage recommendations

Regularly inspect the air pre-charge pressure and the vessel for external damage or corrosion. Check the system pressure and bleed air from the circuit as part of routine maintenance. Replace the expansion vessel if the diaphragm shows signs of failure (frequent pressure loss, waterlogging of the tank) or if repair is not possible.