Expansion vessels are installed on unvented systems to protect from excessive pressure when the water heats up. The vessel or tank is partially filled with air which helps control excess water pressure caused by thermal expansion.

• Suitable for use in water and heating water applications
• WRAS approved potable vessels
• Maintenance free design
• High grade butyl diaphragm
• Reinforced in key areas for longer lifespan
• O-ring valve cap to prevent air leaks