Expansion Vessel FERRO CWU8W for Domestic Hot Water (8 L) - Diaphragm Tank

FERRO CWU8W is an 8-litre diaphragm expansion vessel designed for domestic hot water systems. The membrane-type tank absorbs volume changes and pressure fluctuations in closed hot water circuits, helping to maintain stable system pressure and reduce wear on valves, pumps and water heaters. The compact cylindrical body and threaded connection allow for straightforward installation on boilers, water heaters and pump circulation loops where an 8 L expansion capacity is required.

Advantages

The diaphragm design separates the water and air chambers, preventing air absorption into the circuit and ensuring consistent pressure buffering. The corrosion-resistant internal surface and durable elastomer membrane provide long service life under typical domestic hot water temperatures. Compact dimensions and standard threaded connection make the vessel compatible with common domestic installations while reducing equipment cycling and pressure-related stress.

Suitable for

• Domestic hot water (DHW) systems with closed circuits
• Connection to boilers, water heaters and hot water circulation pumps
• Installations requiring an 8-litre expansion capacity to stabilise pressure
• Retrofit or replacement in residential plumbing systems

Key specifications

• Nominal capacity: 8 litres
• Diaphragm (membrane) type separating air and water chambers
• Designed for closed domestic hot water circuits
• Standard threaded connection for easy mounting
• Suitable for typical potable hot water temperatures used in residential systems
• Compact cylindrical construction for space-efficient installation

How to use

Install the expansion vessel on the hot water circuit at a location recommended by the system manufacturer, typically near the boiler, water heater or circulation pump. Ensure the system is depressurised before making the threaded connection. Pre-charge the air side to the required pressure with a hand pump or compressor if necessary and verify that the vessel is correctly oriented and secured. After installation, fill and pressurise the system, then check for leaks and correct pressure compensation during heating cycles.

Usage recommendations

Verify compatibility with the system's working pressure and pre-charge the vessel to the recommended value for optimal performance. Periodically check the pre-charge pressure and inspect the membrane for signs of wear or loss of elasticity to maintain reliable pressure control in domestic hot water systems.