Expansion Vessel FLAMCO 8 L, 0.5–3.0 bar (model 25300)

FLAMCO expansion vessel 8 L is designed for closed heating and domestic hot water systems to provide hydraulic compensation for thermal expansion. With an 8-litre bladder volume and an adjustable operating pressure range from 0.5 to 3.0 bar, this vessel helps stabilise system pressure, reduce water loss and protect pumps, valves and other components from pressure-related stress. The product is compatible with a wide range of residential and light commercial boilers and heating circuits and is intended for installation on systems where controlled pressure management is required.

Advantages

The expansion vessel provides reliable pressure control across the specified 0.5–3.0 bar range and reduces cycling of circulating pumps by absorbing excess volume during thermal expansion. Its compact 8 L capacity allows flexible installation in tight plant rooms or near boilers. The pre-charged bladder design separates air and water, minimising air ingress into the system and helping to maintain stable pressure for longer periods.

Suitable for

• Closed-loop residential heating systems
• Domestic hot water circuits
• Light commercial boiler installations
• Radiator and underfloor heating systems requiring pressure compensation

Key specifications

• Nominal volume: 8 litres
• Operating pressure range: 0.5–3.0 bar
• Bladder-type vessel with pre-charge
• Suitable for closed heating and hot water systems
• Compact dimensions suitable for confined installation spaces

How to use

Install the FLAMCO expansion vessel in accordance with local plumbing and heating regulations and the system manufacturer’s instructions. Mount the vessel on a straight run of pipe or on the boiler return as recommended, ensuring correct orientation and secure fittings. Set the pre-charge pressure to match the system’s static pressure (typically slightly below the system fill pressure) before putting the system into operation. After installation, pressurise the heating system, check for leaks and verify that the vessel is absorbing expansion by observing stable system pressure during a heat cycle.

Usage recommendations

Regularly inspect the vessel for external damage and check the pre-charge pressure at service intervals. If system pressure drifts or the vessel loses effectiveness, verify bladder integrity and pre-charge pressure and replace the vessel if necessary. Use the vessel within the specified operating pressure range and follow manufacturer guidance for connection fittings and mounting to ensure reliable long-term performance.