Expansion Vessel CIMM ERE 18 L for Central Heating, 1.5/3.5 bar, -10 to +100°C

The CIMM ERE 18 L diaphragm expansion vessel is designed for central heating systems to absorb thermal expansion of the heating medium and maintain stable pressure in closed hydronic circuits. With an 18-litre capacity and an operating pressure range of 1.5/3.5 bar, this vessel fits typical residential and light commercial boilers and radiator systems. It operates across a wide temperature range from -10 to +100°C, making it suitable for systems subject to seasonal and operational temperature variation.

Advantages

The diaphragm design separates the gas and liquid sections to reduce corrosion and prolong component life while ensuring rapid pressure compensation during temperature changes. Compact cylindrical construction allows flexible installation in boiler rooms or near manifolds. The vessel’s rated pressure range and broad temperature tolerance provide reliable protection against overpressure and frequent pump cycling, contributing to more consistent system performance.

Suitable for

• Domestic central heating systems with boilers and radiators
• Closed-loop hydronic heating circuits in small commercial installations
• Systems requiring a compact expansion vessel with moderate capacity
• Applications where temperature variations range from below freezing to high operating temperatures

Key specifications

• Capacity: 18 litres
• Operating pressure range: 1.5 to 3.5 bar
• Temperature range: -10 to +100°C
• Diaphragm (membrane) type separating gas and liquid
• Compact cylindrical form factor for wall or floor mounting

How to use

Install the expansion vessel on the return line or at a location recommended by the heating system designer, ensuring the vessel’s gas side is accessible for pressure adjustment. Pre-charge the vessel to the required initial pressure matching the static system pressure, then connect using appropriate fittings and support to avoid strain. After installation, perform a system fill and venting procedure to remove air and verify that the vessel compensates for pressure changes during heating and cooling cycles.

Usage recommendations

Check and adjust the pre-charge pressure periodically, especially after prolonged downtime or maintenance. Inspect the vessel and its connections for leaks and corrosion during routine servicing. Select the vessel capacity and pre-charge pressure in accordance with the heating system’s volume and manufacturer guidance to ensure stable operation and prevent excessive cycling.