Zilmet CAL-PRO Heating Expansion Vessels

The Zilmet Cal-Pro Expansion Vessel is a robust, maintenance-free solution designed to manage thermal expansion in closed-loop heating systems. By absorbing excess pressure caused by heated water, heating expansion vessel protects boilers, pipes, and radiators from damage, ensuring efficient and reliable operation.

Key Specifications

• Capacity Range: 8–35 litres (suitable for small domestic to light commercial systems).

• Maximum Working Pressure: 10 bar / 145 psi.

• Factory Pre-Charge Pressure: 1.5 bar / 22 psi (adjustable for system requirements).

• Maximum Temperature: 100°C / 212°F.

• Connection Size: 1" BSP female thread (standard for UK heating systems).

• Diaphragm Material: High-grade nitrile rubber (resistant to wear and corrosion).

• Shell Material: Carbon steel with epoxy-coated finish for durability.

Features & Benefits

• Pressure Stabilisation: Prevents pressure spikes in heating systems, extending equipment lifespan.

• Compact Design: Space-saving and easy to install in boiler rooms or compact spaces.

• Adjustable Pre-Charge: Customisable to match system static pressure.

• Corrosion-Resistant: Epoxy coating protects against rust in damp environments.

• Compliance: Meets UK and EU standards for heating system components.

Typical Applications

• Domestic and commercial boiler systems.

• Underfloor heating circuits.

• Solar thermal installations.

Installation Notes

• Mount vertically to optimise diaphragm performance.

• Ensure pre-charge pressure matches system static pressure before installation.

• Consult a Gas Safe registered engineer for compliance with UK building regulations.