--- product_id: 122754565 title: "500 Litre Aquasystem Replaceable Membrane Potable Water Expansion Vessel with 1 1/4\" Connection" brand: "aquasystems" price: "FREE" currency: EUR in_stock: false url: https://www.desertcart.hr/products/122754565-500-litre-aquasystem-replaceable-membrane-potable-water-expansion-vessel-1 store_origin: HR region: Croatia --- # 500 Litre Aquasystem Replaceable Membrane Potable Water Expansion Vessel with 1 1/4" Connection **Brand:** aquasystems **Price:** FREE **Availability:** ❌ Out of Stock ## Quick Answers - **What is this?** 500 Litre Aquasystem Replaceable Membrane Potable Water Expansion Vessel with 1 1/4" Connection by aquasystems - **How much does it cost?** FREE with free shipping - **Is it available?** Currently out of stock - **Where can I buy it?** [www.desertcart.hr](https://www.desertcart.hr/products/122754565-500-litre-aquasystem-replaceable-membrane-potable-water-expansion-vessel-1) ## Best For - aquasystems enthusiasts ## Why This Product - Trusted aquasystems brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Description 500 Litre Replaceable Membrane Potable Water Expansion Vessel Specification: * 500 Litre * Blue Epoxy Coated Steel Container * Replaceable EPDM Membrane * Bolted Stainless Steel Flange * Maximum Pressure: 10 Bar * Pre-set Charge Pressure: 3.5 Bar * Connection: 1 1/4" MBSP * Height: 1493mm * Diameter: 750mm * WRAS Approved These expansion vessels for potable hot water are manufactured to comply with UK water regulations and are tested and certified by WRAS. All Reliance expansion vessels are supplied with a replaceable membrane, which separates the water and air to prevent contamination of the water system, corrosion of the pressure vessel or pressure loss in the water system. The main purpose of an expansion vessel is to compensate for the increase in volume of water due to the varying water temperatures in hot water systems. When water is heated it expands and as water is not compressible this increased volume will create a rise in pressure within the system. As an example: water being heated from 0°C-100°C will increase by approximately 4.5%. The expansion vessel allows for this extra space, as when water temperature increases the membrane inside the vessel expands to allow the water to fill the vessel. The membrane will continue to expand until the system reaches its maximum temperature. ## Features - Capacity: 500 Litre Pre-set Pressure: 3.5 bar Connection: 1 1/4" MBSP Height: 1493mm Diameter: 750mm ›See more product details ## Images ![500 Litre Aquasystem Replaceable Membrane Potable Water Expansion Vessel with 1 1/4" Connection - Image 1](https://m.media-amazon.com/images/I/31wx039yBGL.jpg) --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.hr/products/122754565-500-litre-aquasystem-replaceable-membrane-potable-water-expansion-vessel-1](https://www.desertcart.hr/products/122754565-500-litre-aquasystem-replaceable-membrane-potable-water-expansion-vessel-1) --- *Product available on Desertcart Croatia* *Store origin: HR* *Last updated: 2026-05-15*