Dezincification-resistant (DZR) brass can help prevent corrosion from negatively affecting various components, including valves used in a number of applications. Although many applications use valves and other fittings made from normal brass alloys, certain impurities could cause a type of corrosion known as dezincification. In applications where dezincification is a risk, DZR brass valves provide enhanced protection to maximize the longevity of certain components.
Here we’ll review what dezincification specifically is and how DZR brass valves and other parts can protect against it.
What Is Dezincification?
Brass is a combination of mostly copper and zinc. While copper is un-reactive, it is vulnerable to damage and extremely malleable. Zinc, on the other hand, is strong but reactive and more easily corroded. When the two metals combine to form brass, the resulting metal is ideally both strong and un-reactive, featuring the favorable properties of copper and zinc. However, normal brass is potentially still vulnerable to corrosion in the form of dezincification.
Dezincification entails the loss of zinc through corrosion because of its reactiveness. It’s a certain type of corrosion process resulting from water contact. In turn, water removes zinc from the copper alloy, forming a copper-rich and porous metal with compromised mechanical strength. Specifically, the removal of zinc leaves a layer of Cu and Cu oxide. Over time, further corrosion can continue underneath this layer, gradually leaving weaker copper in place of more durable brass. An in-service valve suffering from dezincification can have a white powdery substance or mineral stains on its exterior surface.
If dezincification is allowed to continue, the corrosion will eventually weaken the metal and enable gases or liquids to seep through it.
What Is DZR Brass?
Dezincification-resistant (DZR) brass helps prevent dezincification of brass materials, increasing their lifespan and enabling various applications to benefit from consistent durability. Many parts feature DZR brass construction, including fittings and valves in potable water and other types of environments with corrosive water.
DZR brass’s composition features superior strength that makes it suitable for a wider range of applications in need of a reliable metal product.
Generally, DZR brass includes higher copper content along with lower zinc content. NSF lead free* DZR alloys are also available. Additionally, other trace elements compose this metal. A unique heat treatment process further enhances the properties of DZR brass.
Strict control over every stage of the manufacturing process helps assure dezincification resistance. It’s important for fabricators to have control over casting, brass rod production, heat treating, and shaping, along with other processes, to eliminate the possibility of corrosion. It’s equally crucial to have total control over major alloying elements, and manufacturers must also exclude any unwanted impurities.
Following heat treatment, dezincification tests can perform periodic checks on components, which helps make sure that the heat treatment was successful and that the metal features the correct composition. The closely controlled dezincification test involves 24-hour exposure to a type of hot cupric chloride solution. At RED-WHITE VALVE CORP., our products undergo the ISO 6957:1988 (Copper alloys – Ammonia test for stress corrosion resistance) test. This uses a test solution with a pH of 9.5. Following exposure, the test applies slight deformation to samples prior to inspection, which reveals fine cracks and other faults.
Reliable DZR Brass Products from RED-WHITE VALVE CORP.
DZR brass valves and other products can increase the strength of systems exposed to highly corrosive water, eliminating the need for frequent maintenance and the replacement of parts. RED-WHITE VALVE CORP. offers a wide selection of DZR brass products to meet the needs of a diverse range of applications.
For more information about our products and assistance with finding the right product for your application, contact us today.