Expansion vessel Comap SOLARIX 18/2.5, capacity 18 L, precharge 2.5 bar, max 10 bar

Comap SOLARIX 18/2.5 is an 18-litre diaphragm expansion vessel designed for closed heating and solar systems. The vessel has a factory precharge of 2.5 bar and a maximum allowable working pressure of 10 bar. It absorbs thermal expansion of the system fluid, reduces pressure spikes and helps stabilise operation by limiting on/off cycling of pumps and valves in domestic and small commercial installations.

Advantages

The diaphragm construction separates air and liquid, preventing gas absorption into the system and maintaining consistent performance over time. The factory precharge of 2.5 bar allows for immediate installation in systems with corresponding static pressure, while the 10 bar maximum pressure rating ensures compatibility with a wide range of closed heating and solar circuits. Its compact 18 L capacity offers a balance between effective expansion compensation and space efficiency.

Suitable for

• Domestic central heating systems
• Roof-mounted and drainback solar thermal circuits
• Small commercial heating installations
• Boiler and heat pump systems requiring closed-loop expansion control

Key specifications

• Capacity: 18 litres
• Factory precharge pressure: 2.5 bar
• Maximum allowable pressure: 10 bar
• Diaphragm (membrane) type vessel
• Designed for closed heating and solar systems
• Compact cylindrical form factor suitable for wall or floor mounting

How to use

Install the expansion vessel in a position where it is accessible for inspection and maintenance, typically near the system pump or manifold. Before connection, verify that the system’s static pressure matches the vessel precharge or adjust the vessel precharge as required using a suitable pressure gauge and pump. Connect to the system using appropriate fittings and ensure all connections are tightened and leak-free. After filling and venting the system, confirm that the operating pressure remains within the acceptable range and that the vessel accommodates normal thermal expansion without excessive cycling of system components.

Usage recommendations

For reliable long-term performance, check the vessel precharge annually and after major servicing or system draining. Ensure compatibility with system fluid (antifreeze or glycol mixes) and follow manufacturer guidance on minimum installation clearances and mounting orientation.