Pressure expansion vessel - water supply systems - 300l; 10bar; 5/4"; horizontal IVAR.AFH 300 - AQUACOLD

Product detailed description

Pressure expansion vessels are essential components in closed potable water systems where thermal expansion must be safely accommodated. This model is commonly used in residential, commercial and industrial buildings with central water heating systems. Installers typically integrate these vessels into systems with fixed pressure points, such as those with pressure-reducing valves or pump controls. The horizontal orientation allows for space-efficient installation in mechanical rooms, basements or utility areas. The vessel’s design ensures that pressure fluctuations are absorbed without overloading the system, helping to prevent damage to pipes, fittings and appliances.

Correct sizing and selection of expansion vessels depend on system volume, temperature range and pressure conditions. The 300L capacity is suitable for systems with moderate thermal expansion, while the 10bar pressure rating ensures compatibility with standard domestic and low-pressure commercial water systems. The 5/4 inch connection size allows for integration with standard pipe sizes and fittings. The operating temperature range from -10°C to +99°C, with a recommended maximum of +80°C, ensures suitability for typical domestic hot water applications.

Technical parameters

Code	A042L51
Brand	IVAR

The technical parameters define the vessel’s suitability for specific system conditions. The 10bar pressure rating ensures compatibility with standard water supply systems, while the 300L capacity is appropriate for systems with moderate thermal expansion. The 5/4 inch connection size is a key factor in system integration. The recommended operating temperature up to +80°C ensures the EPDM membrane remains effective and durable under normal operating conditions.

Installation and connection

This vessel is installed in the water supply system to absorb thermal expansion. The horizontal orientation requires secure mounting on a flat surface or wall. The 5/4 inch connection should be fitted with appropriate pipe fittings and sealed with thread sealant or PTFE tape. Installers should ensure the vessel is positioned close to the heating source or pressure point to maximise efficiency. Common installation errors include incorrect orientation, insufficient support, and failure to check the pre-charge pressure before commissioning. Always verify the system pressure and ensure the vessel is installed in a location that allows for easy access during maintenance.

Compatibility and accessories

This vessel is compatible with standard potable water systems using EPDM-compatible media. It is typically used with pressure-reducing valves, pressure switches and pump controls. Accessories such as mounting brackets or wall hangers may be required for secure installation. Related models include IVAR.AC (for hanging installation), IVAR.AFH (horizontal with feet) and IVAR.AFV (vertical with base). These alternatives offer different mounting options depending on space constraints and system layout.

Technical background for designers

The vessel operates by separating water and air using a replaceable EPDM membrane. As water expands due to heating, the membrane compresses the air chamber, preventing pressure surges in the system. The EPDM material is resistant to ozone and UV light, ensuring long-term durability. The vessel must be pre-charged with air to a pressure slightly below the system’s minimum operating pressure. System integration requires careful calculation of expansion volume to ensure the vessel can accommodate the expected thermal expansion without over-pressurisation. The vessel’s service life is affected by operating temperature, water quality and correct pre-charge pressure.

Service and operation

Regular checks should be performed to ensure the vessel is functioning correctly. The pre-charge pressure should be verified periodically and adjusted if necessary. The membrane should be inspected for signs of wear or damage, and replaced if required. No specific service intervals are provided in the brief, but maintenance should be carried out according to the manufacturer’s technical data sheet. The vessel should be drained and flushed if the system is to be left unused for extended periods. Always follow the manufacturer’s guidelines for safe operation and maintenance.

Frequently asked questions

Can this vessel be used in a closed-loop hot water system?
Yes, the vessel is suitable for closed-loop hot water systems where thermal expansion must be accommodated. The EPDM membrane is compatible with potable water and the operating temperature range supports typical domestic hot water conditions.

Is the EPDM membrane replaceable?
Yes, the membrane is designed to be replaceable, allowing for maintenance and repair without replacing the entire vessel. Replacement should be carried out according to the manufacturer’s instructions to ensure correct installation and performance.

Can this vessel be mounted vertically?
No, this model is designed for horizontal installation only. For vertical mounting, alternative models such as IVAR.AFV should be considered.

What is the maximum operating temperature for this vessel?
The recommended maximum operating temperature is +80°C. While the vessel can technically operate up to +99°C, it is advised to keep the temperature within the recommended range to ensure optimal performance and longevity of the EPDM membrane.