Safety valve 8115 2.5 bar 3/4 inch, solar 8115.20.150

Protection of solar systems against overpressure

The safety valve 8115.20.150 is a diaphragm element protecting solar installations and other pressure systems with liquid or inert gas. It operates automatically – it opens when pressure exceeds 2.5 bar and closes after it drops. It is designed for operation in conditions where the risk of over‑pressure is real, e.g., sudden pump shutdown or collector overheating.

For the installer – clear selection and installation criteria

Installation is possible only in a vertical position, with the inlet at the bottom – there is no flexibility in orientation. This is crucial information: incorrect installation can cause improper operation or damage to the valve. The G 3/4" connection allows easy integration with larger circuits, and its flow capacity corresponds to power up to 101 kW – which matches a collector area of about 100 m². In practice, this means that for typical residential systems with 6–8 flat collectors this valve is the standard choice.

What makes it operate safely and durably?

The valve is intended for a medium containing up to 50 % glycol – making it ideal for solar systems in regions with low winter temperatures. The maximum operating temperature is 160 °C – far above typical values in normal service conditions, providing a safety margin in case of thermal failures. It has no capillary – this simplifies the design and reduces the risk of clogging or damage during long‑term operation.

It is worth remembering: if the valve drips – it does not necessarily mean it is defective. Often it signals a design error: lack of an expansion tank, improperly sized pump, or insufficient venting. The valve performs its function – and the installer should look for the cause elsewhere.