Expansion vessel for domestic hot water CIMM ACS 24 L, pressure 2.5/8 bar, temperature -10 to +100 °C

The Expansion vessel for domestic hot water CIMM ACS 24 L is a membrane-type pressure vessel intended for closed DHW systems. It has a nominal volume of 24 litres and is built to accommodate thermal expansion in domestic hot-water circuits. The vessel supports operation across a wide temperature range from -10 °C to +100 °C and is designed to reduce pressure fluctuations and relieve stress on boilers, heaters and storage tanks connected to the system.

Advantages

The device features a membrane design that separates the water from the pre-charged gas chamber, ensuring consistent pressure buffering and minimizing waterlogging. Compact construction and nominal capacity make it suitable for most household hot-water systems while maintaining stable hydraulic conditions. Its temperature tolerance allows use with typical domestic heaters, and the rated maximum working pressures support safe operation within common DHW installations.

Suitable for

• Closed domestic hot-water (DHW) systems
• Boiler and water heater installations requiring thermal expansion compensation
• Hot-water storage tanks and accumulators
• Systems where pressure fluctuation reduction and protection of fittings are needed

Key specifications

• Nominal volume: 24 litres
• Maximum working pressure: up to 8 bar (with an intermediate reference at 2.5 bar for specific operating conditions)
• Operating temperature range: -10 °C to +100 °C
• Membrane (diaphragm) separation between fluid and gas chamber
• Designed for installation in closed hot-water circuits

How to use

Install the expansion vessel on the return line or at a suitable point in the closed DHW circuit following local plumbing codes and manufacturer installation guidelines. Verify the pre-charge pressure of the gas chamber before connection and adjust it to match the static system pressure if necessary. Mount the vessel on an appropriate bracket or support to prevent mechanical stress on connections. After installation, fill and pressurize the system, then inspect for leaks and correct operation of the pressure-buffering function.

Usage recommendations

Check the pre-charge regularly and inspect the membrane for integrity during scheduled maintenance. Ensure the vessel’s pre-charge is compatible with the system’s static pressure and consider using an automatic air-vent and pressure gauge for ongoing monitoring. Replace the expansion vessel if signs of membrane failure, persistent waterlogging, or pressure instability occur.