Expansion Vessel (Diaphragm) Reflex Solar S 12 1.5/10 bar max 70°C

Reflex Solar S 12 diaphragm expansion vessel is designed for closed solar and small heating systems to compensate for thermal expansion of heat transfer fluids. With a nominal volume of 12 liters and factory precharge at 1.5 bar, this expansion vessel supports stable hydraulic balance, reduces the risk of pressure spikes and protects system components against overpressure in circuits with maximum operating pressure up to 10 bar and maximum fluid temperature up to 70°C.

Advantages

The vessel uses a durable elastomer diaphragm separating the fluid chamber from the precharged gas chamber to maintain consistent pressure behavior over repeated thermal cycles. Its compact cylindrical design allows easy installation in tight spaces near collectors, pumps or manifolds. Factory precharge simplifies commissioning, and the product is manufactured to resist corrosion and provide reliable performance in solar thermal and small closed-loop heating applications.

Suitable for

• Closed solar thermal circuits and domestic hot water systems
• Small closed heating installations and buffer circuits
• Systems requiring pressure compensation and overpressure protection up to 10 bar
• Installations with fluid temperatures up to 70°C

Key specifications

• Nominal volume: 12 liters
• Precharge pressure: 1.5 bar (factory set)
• Maximum operating pressure: 10 bar
• Maximum fluid temperature: 70°C
• Diaphragm-type (elastomer) separation of gas and fluid chambers
• Compact cylindrical construction for wall or stand mounting

How to use

Mount the expansion vessel according to system layout and local regulations, observing recommended orientation and securing methods. Connect the vessel to the system at a point where it will reliably receive expanding fluid, such as near the pump or manifold. Verify the factory precharge before installation and adjust only when the system is depressurized and drained to the appropriate level. After connection, pressurize the system to working pressure and check for leaks, stable pressure readings and correct interaction with the pressure relief and safety devices.

Usage recommendations

Check the precharge periodically and adjust as needed when the system is cold; inspect the vessel for external damage or corrosion at routine maintenance intervals. Use compatible heat transfer fluids and observe the maximum temperature and pressure limits to ensure long service life. For systems with higher pressures, larger volumes or temperatures above 70°C, select an appropriately rated expansion vessel.