Expansion vessel set - for boiler assembly - 5/4 "Mx3/4 "F IVAR.EXPANZ

Product detailed description

This expansion vessel set is commonly used in residential and commercial heating systems where thermal expansion of water requires controlled compensation. Installers working on central heating boilers, especially those using closed-loop systems, will find this set essential for ensuring stable pressure levels and preventing system stress caused by thermal expansion. It is typically installed as part of a boiler assembly, ensuring safe and efficient operation under normal load conditions. The vessel’s size and connection specifications make it suitable for medium-sized systems requiring consistent performance over long operating cycles.

The set is assembled to fit standard boiler configurations and is designed to integrate seamlessly with IVAR boiler assemblies. It is particularly useful in systems where expansion vessels need to be mounted separately from the boiler body or where existing piping requires specific thread conversions. The included connecting kit ensures secure and leak-free installation, reducing commissioning time and potential errors during setup.

Technical parameters

Volume of expansion vessel	18 l
Code	550530
Brand	IVAR

The 18 L capacity is determined based on the expected thermal expansion volume in the system. This size is suitable for systems with moderate heat output, such as single-family homes or small apartment blocks. The pressure rating of PN 3.5 ensures compatibility with standard domestic heating pressures. The maximum operating temperature of +120°C aligns with typical boiler operating conditions, allowing for safe use in both standard and condensing boiler applications.

Installation and connection

To install the expansion vessel set, ensure that the boiler assembly is compatible with the 5/4'' male external thread provided on the vessel’s inlet side. Connect the vessel to the system using the 3/4'' internal female thread on the vessel’s outlet. Use the included connecting kit to bridge any differences in pipe routing or orientation. Secure all connections with appropriate sealing tape or compound to prevent leaks. Verify that the vessel is mounted in a location accessible for future inspection and maintenance, and that it is not subject to mechanical strain from adjacent components. Common installation errors include incorrect thread alignment and insufficient sealing at the connection points, which can lead to pressure loss or leakage over time.

Compatibility and accessories

This expansion vessel set is specifically designed for use with IVAR boiler assemblies. It is not interchangeable with non-IVAR systems unless confirmed through detailed specification matching. To complete the installation, no additional components are required beyond the included connecting kit. Ensure that the boiler control system supports the inclusion of an external expansion vessel and that the overall system configuration allows for proper air venting and pressure regulation.

Technical background for designers

The expansion vessel operates by absorbing excess thermal expansion of water in the heating circuit. It contains a flexible diaphragm separating the water side from a pre-charged air chamber. As water expands due to heating, the diaphragm compresses the air, maintaining system pressure within acceptable limits. The vessel is constructed from materials capable of withstanding repeated thermal cycles and high temperatures up to +120°C. Proper integration into the system involves positioning the vessel close to the boiler but isolated from direct heat sources. System efficiency and longevity depend on correct sizing and installation, as well as regular monitoring of pressure and condition of the vessel’s seals.

Service and operation

During operation, the vessel should be monitored periodically for signs of pressure imbalance or physical damage. Check for rigid mounting and ensure that the vessel remains free from mechanical stress. While the brief does not specify mandatory service intervals, visual inspections and pressure checks are recommended as part of routine system maintenance. Any detected anomalies should prompt further investigation to avoid potential system failure.

Frequently asked questions

Can this expansion vessel be connected to a non-IVAR boiler?
It is specifically designed for IVAR boiler assemblies. Connection to other systems requires confirmation of compatibility via detailed specification comparison.

What is the maximum allowable working temperature?
The vessel is rated for operation at a maximum temperature of +120°C, suitable for most standard and condensing boiler applications.

Is a separate mounting bracket needed for installation?
No, the vessel is designed for direct connection using standard pipe fittings. Mounting brackets are not included but may be used depending on site requirements.

How should the vessel be positioned relative to the boiler?
Mount the vessel in a location that is easily accessible and not subject to mechanical strain or direct heat exposure. It should be positioned to allow full drainage if required.

Documents for download

• CSTL_IVAR.EXPANZ (PDF)
• SKTL_IVAR.EXPANZ czver (PDF)