Solar expansion vessel IBAIONDO 18L

Product detailed description

Solar expansion vessels are essential components in closed-loop solar thermal systems, particularly in installations where the heat transfer fluid contains glycol. These systems are commonly found in residential and commercial solar water heating applications. The vessel compensates for thermal expansion caused by temperature fluctuations in the collector loop. Installers typically encounter these systems in medium-sized solar installations where the risk of overpressure or vacuum formation is higher due to the glycol content and variable solar irradiation levels.

Proper sizing and positioning of the expansion vessel are critical to maintaining system integrity and ensuring long-term reliability. The vessel must be integrated into the circuit in a location that allows for easy access during commissioning and maintenance. It should be installed after the pump and before the collector array to ensure that all thermal expansion is effectively absorbed. The vessel must also be protected from direct exposure to sunlight and extreme ambient temperatures to prevent premature degradation of internal components.

Technical parameters

Type	Solar expansion vessel
Volume	18 l
Max. working pressure	10 bar
Pre-charge pressure	2.5 bar
Operating temperature	-10°C to +100°C (peaks up to 130°C)
Membrane	DIN 4807-3
Max. glycol content	50 %
Colour	White
Connection	3/4 inch
Net weight	3.120 kg
Warranty	2 years
EAN	5900308748794
Code	NS.18.IB
Brand	Hydroland

The 18-litre capacity ensures sufficient space for thermal expansion in systems with moderate to high glycol content. The maximum working pressure of 10 bar and pre-charge pressure of 2.5 bar are key factors in determining the vessel’s suitability for specific system designs. The operating temperature range from -10°C to +100°C, with short-term tolerance up to 130°C, makes it suitable for solar systems in temperate climates with occasional high-temperature spikes. The membrane conforms to DIN 4807-3, ensuring compatibility with glycol-based fluids and resistance to thermal stress.

Installation and connection

The vessel is equipped with a 3/4 inch threaded connection, which must be matched with the corresponding pipe size in the system. Prior to installation, verify that the pre-charge pressure aligns with the system’s operating conditions. The vessel should be mounted vertically, with the air valve accessible for pressure adjustments. Common installation errors include incorrect orientation, which can lead to uneven pressure distribution, and failure to check the initial pressure setting, which can result in system instability or inefficient operation. Ensure that the vessel is installed in a location free from mechanical stress and vibration.

Compatibility and accessories

This solar expansion vessel is designed for use with glycol-based heat transfer fluids and is compatible with standard solar thermal systems that operate within the specified temperature and pressure ranges. For optimal performance, it should be used in conjunction with a pressure relief valve and a pressure gauge to monitor system conditions. No additional accessories are required for basic operation, though these monitoring devices are recommended for system diagnostics and safety. There are no alternative or related products listed for this model.

Technical background for designers

The vessel operates based on the principle of separating the gas and liquid phases of the heat transfer fluid using an internal membrane. This prevents direct contact between the fluid and the vessel’s internal chamber, reducing corrosion and extending service life. The membrane is constructed according to DIN 4807-3 standards, ensuring resistance to glycol and thermal cycling. The vessel is made from powder-coated steel, providing durability and protection against environmental factors. Its integration into the system depends on accurate sizing relative to the system’s thermal mass and expansion characteristics. The presence of glycol in the fluid increases the risk of volume expansion, making correct pre-charge pressure and vessel capacity essential for stable operation.

Service and operation

Periodic checks of the pre-charge pressure are necessary to maintain system performance. If the pressure drops below the recommended level, it should be adjusted using a suitable pump and pressure gauge. The vessel does not require regular maintenance beyond these checks, provided the system remains sealed and the membrane is intact. No specific service intervals are defined in the product documentation, but any visible signs of leakage or pressure irregularities should be investigated immediately to prevent system failure.

Frequently asked questions

Can the vessel handle glycol concentrations above 50%?
No, the maximum allowable glycol content is 50%. Exceeding this limit may compromise the membrane integrity and reduce the vessel’s lifespan.

Is the vessel suitable for open-loop solar systems?
No, it is specifically designed for closed-loop systems. Using it in an open system would expose the internal components to atmospheric pressure and potential contamination.

What is the recommended mounting orientation?
The vessel should be mounted vertically to ensure proper gas-liquid separation and to allow access to the air valve for pressure adjustments.

Can the pre-charge pressure be adjusted after installation?
Yes, the pre-charge pressure can be modified using a standard pressure pump. However, it should be set according to the system’s design specifications before commissioning.

Documents for download

• Instruction manual (Slovak)
• Manual (English)
• Declaration of conformity (Slovak)
• Declaration of conformity (English)