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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, it protects boilers, pipes, and radiators from damage, ensuring efficient and reliable operation.
Key Specifications
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Capacity Range: 8–35 litres (suitable for small domestic to light commercial systems).
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Maximum Working Pressure: 10 bar / 145 psi.
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Factory Pre-Charge Pressure: 1.5 bar / 22 psi (adjustable for system requirements).
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Maximum Temperature: 100°C / 212°F.
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Connection Size: 1" BSP female thread (standard for UK heating systems).
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Diaphragm Material: High-grade nitrile rubber (resistant to wear and corrosion).
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Shell Material: Carbon steel with epoxy-coated finish for durability.
Features & Benefits
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Pressure Stabilisation: Prevents pressure spikes in heating systems, extending equipment lifespan.
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Compact Design: Space-saving and easy to install in boiler rooms or compact spaces.
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Adjustable Pre-Charge: Customisable to match system static pressure.
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Corrosion-Resistant: Epoxy coating protects against rust in damp environments.
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Compliance: Meets UK and EU standards for heating system components.
Typical Applications
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Domestic and commercial boiler systems.
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Underfloor heating circuits.
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Solar thermal installations.
Installation Notes
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Mount vertically to optimise diaphragm performance.
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Ensure pre-charge pressure matches system static pressure before installation.
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Consult a Gas Safe registered engineer for compliance with UK building regulations.
- Type Expansion Vessel for Heating Systems
- Vendor Zilmet
- SKU EVP4
Please note: Delivery times may vary depending on location, with specific details outlined below.
Standard Delivery
UK Mainland
- Delivery Time: 2–3 working days
- Free Delivery for orders over £50
- Delivery fee of £5.99 for orders under £50
Channel Islands
- Postcodes Covered: GY*, IM*, JE*
- Minimum Order: £50
- Delivery Fee: £70
Northern Ireland, Offshore Territories & Scottish Islands
- Postcodes Covered: BT*, HS*, KW, ZE
- Minimum Order: £50
- Delivery Fee: £35
Express Delivery
UK Mainland
- Delivery Time: 1–2 working days
- Free Delivery for orders over £50
- Delivery fee of £9.95 for orders under £50
Same Day Delivery
Greater London
- Eligible Postcodes:
E*, EC*, N*, NW*, SE*, SW*, W*, WC*, HA*, UB*, EN*, IG*, RM*, KT*, SM*, CR*, BR*, DA*, TW* - Minimum Order: £50
- Same Day Delivery Fee: £60
- Special Requests or Locations:
For areas outside these postcodes or urgent quotes, please email orders@qualityheating.co.uk and we’ll do our best to accommodate.
Collections
Want to collect your order instead?You’re welcome to do so — just email us at orders@qualityheating.co.uk or message us via WhatsApp with your preferred collection time, and we’ll confirm the details.
Collection address: 284 Water Rd, Unit 9, London, HA0 1HX