Expansion Vessel CIMM ACS 12 L for DHW, 2.5/10 bar, -10 to +100 °C, model 511242

The CIMM ACS 12 L expansion vessel for DHW is designed to control pressure changes in closed domestic hot water systems. With a 12-litre effective capacity and a diaphragm design approved for potable water (ACS rating), this vessel accommodates thermal expansion and reduces stress on pipes, valves and fixtures. It operates across a temperature range from -10 to +100 °C and is suitable for typical residential and small commercial installations where water hygiene and pressure stability are required.

Advantages

The diaphragm construction separates the potable water from the gas charging chamber, maintaining sanitary conditions while providing reliable absorption of volume fluctuations. A working pressure range from 2.5 to 10 bar allows use in most domestic hot water circuits, and the compact 12-litre size fits easily into plant rooms or under-sink installations. The ACS rating confirms suitability for drinking water applications and compliance with relevant sanitary requirements.

Suitable for

• Residential domestic hot water (DHW) systems
• Small commercial DHW installations such as offices or cafés
• Closed potable water circuits requiring pressure control and expansion compensation
• Retrofitting existing water heaters and storage tanks to reduce cycling and pressure spikes

Key specifications

• Nominal capacity: 12 litres (effective volume for expansion)
• Approved for potable water: ACS-rated diaphragm design
• Operating pressure range: 2.5–10 bar
• Temperature range: -10 °C to +100 °C
• Mounting: compact design suitable for wall or floor-mounted plant spaces

How to use

Install the expansion vessel in the cold-water line of a closed DHW circuit following local plumbing codes and manufacturer mounting recommendations. Ensure the vessel pre-charge (gas pressure) matches the static system pressure before connecting; adjust the pre-charge if necessary using an appropriate valve. Position the vessel so that the water connection is accessible for maintenance and check that all fittings and isolation valves are properly sealed. Regularly inspect for visible damage, leaks or loss of pre-charge and service according to local regulations.

Usage recommendations

Use the CIMM ACS 12 L expansion vessel in systems where potable water compatibility is required. Verify pre-charge pressure at installation and after prolonged downtime, and perform periodic checks to ensure the diaphragm integrity and correct operating pressure. For systems with higher capacity or unusual pressure conditions, consult a heating/plumbing specialist to select a suitably sized vessel.