Expansion vessel VAREM R1018228, 18 L capacity, for heating and potable systems

VAREM expansion vessel R1018228 with 18 L nominal capacity is designed to control thermal expansion and pressure fluctuations in closed heating and potable water systems. The tank uses an internal elastomeric membrane to separate the air cushion from the water side, maintaining constant operating pressure and reducing the frequency of pump cycling. Its compact form factor makes it suitable for installations where space is limited while providing protection for boilers, heat pumps, solar thermal circuits and piping against overpressure and hydraulic shocks.

Advantages

The diaphragm design prevents mixing of air and water, ensuring reliable pressure maintenance and reducing corrosion risk. An 18 L working volume provides sufficient buffering for small to medium domestic systems. The compact construction and standardized connections allow for straightforward integration into existing heating or potable water circuits. Materials and design focus on durability and stable performance under typical domestic operating conditions.

Suitable for

• Domestic boiler heating systems
• Heat pump installations
• Solar thermal systems
• Small closed potable water circuits requiring pressure buffering

Key specifications

• Nominal capacity: 18 litres
• Internal diaphragm separates air and water
• Compact tank body suitable for space-constrained installations
• Designed for closed heating and potable water systems
• Reduces pressure fluctuations and pump cycling

How to use

Install the expansion vessel on the system return line or as recommended by the system designer, ensuring the vessel is positioned vertically for correct diaphragm operation. Pre-charge the air side to the recommended pressure for the installation, typically matching the static system pressure, and verify tight connections before commissioning. During routine system checks, confirm the pre-charge pressure, inspect for visible leaks and ensure the vessel remains free of external damage. Follow local codes and the system manufacturer's instructions when integrating the vessel into potable water loops.

Usage recommendations

Verify pre-charge pressure before installation and adjust to match system static pressure. Periodically check the vessel during scheduled maintenance to maintain correct pre-charge and detect any loss of diaphragm integrity. For potable water applications, follow hygiene and backflow prevention guidelines when connecting the vessel.

Keywords: VAREM expansion vessel R1018228 18 L expansion tank heating potable systems diaphragm compact