Flamco Flexvent Solar is a manually operated air vent valve specially designed for solar thermal systems operating with glycol-based fluids. Unlike standard Flexvent automatic air vents, the Solar version is adapted for the extreme operating conditions typical of solar circuits – high temperatures, alternating overpressure and vacuum, as well as the presence of glycol mixtures. The valve operates on the float principle: air accumulating at the highest point of the system causes the float to drop, thereby opening the vent valve and releasing the air. After venting, the float rises again and closes the valve.

The compact brass body with R 3/8" male thread allows easy installation even in space-restricted areas of the collector circuit. The valve is supplied without a shut-off valve and without a key – operation is manual, using a screwdriver or key (accessories can be purchased separately). A relatively large air cushion in the upper part of the body protects the valve seat against contamination and prevents leakage of the medium. Each unit undergoes a factory pressure test, guaranteeing reliability and tightness when put into operation.

Features and benefits

• Designed for solar systems with glycol-based fluids (concentration up to 50%)
• Extreme temperature range -10 °C to +200 °C, short-term (peak) up to 120 °C
• Max. operating pressure 10 bar
• Float principle – reliable and repeated air venting without the need for supervision
• Brass body resistant to corrosion and glycol-based media
• Compact dimensions facilitating installation even in confined spaces
• Large air cushion protects the seat against contamination
• Each valve tested before dispatch from the factory
• Manual operation by screwdriver or key (suitable for solar applications)
• Can be supplemented with a shut-off valve or key as an accessory