The UAE produces around 14% of the world's desalinated water. Roughly 99% of Dubai's drinking water reaches taps via desalination plants on the Arabian Gulf coast. This is well known. What is less appreciated outside the region is what that mineral profile does to standard brass over time.
What is dezincification, and why does it happen here
Brass is a copper-zinc alloy. In aggressive water chemistries — typically those combining elevated chloride content with low residual hardness — the zinc preferentially leaches out, leaving behind a porous, structurally weak copper matrix. The fitting still looks like brass on the outside, but it is no longer brass on the inside. Eventually it fails: pinhole leaks, fractures under pressure, full collapse of the body.
Desalinated seawater is, by design, soft water with low residual hardness. Combined with the chlorine added for disinfection and the temperature variations a Dubai installation sees between summer and winter, it sits squarely in the "aggressive" zone for standard brass.
What DZR actually changes
Dezincification-resistant brass is not a coating or a treatment. It is the metallurgy itself: tightly controlled copper-to-zinc ratios, plus small additions of arsenic, antimony, phosphorus or boron that block the zinc-leaching mechanism at the grain-boundary level.
The standards reference is European EN 12164/12165, and individual countries identify the alloy with letter marks: "CR" or "DZR" in the UK, "DR" in some other markets. In MT's potable-water range, valve bodies are forged from DZR brass alloys compliant with EN 12164/12165 — the same alloy family that underpins WRAS and KIWA approvals.
The lead-free transition
An additional dimension is the move away from leaded brass. The EU Drinking Water Directive establishes positive lists of approved materials for components in contact with potable water; alloys must show migration of less than 5 µg/L of lead. Modern lead-free DZR alloys such as CW724R (silicon-modified) and CW511L meet this threshold while preserving DZR performance.
While ECAS in the UAE has not yet harmonised fully with the EU positive lists, projects designed by European consultants increasingly write the EU thresholds into specifications by reference. Specifying lead-free DZR today is a hedge against tomorrow's tender requirements.
When to insist on DZR — and when standard brass is fine
Our practical guidance for UAE projects:
- Always DZR: potable water (cold and hot), reverse-osmosis loops, irrigation with treated effluent, chilled-water systems with anti-corrosion additives, marine and coastal installations.
- DZR strongly recommended: pressure-reducing valves, mixing valves, anything specified for residential or hospitality projects with a 25-year expected service life.
- Standard brass acceptable: dry compressed-air lines, industrial gas at room temperature, low-stakes utility applications where access for replacement is straightforward.
If a tender does not specify DZR explicitly, ask. Adding two letters to a specification line is the cheapest insurance you will buy on a project.
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