01/03/2012

Stauffenberg GmbH & Co. KG, Walter

Top-class surface for high-pressure ball valves

The high-grade protection of steel surfaces is part of the standard delivery condition at Walter Stauffenberg. This also applies in the high-pressure ball valve segment where the valves are given a top quality zinc-iron coating. This not only enhances their appearance, but provides additional protection against corrosion as well. Electrolytic plating with zinc provably upgrades the corrosion-protective properties. Surfaces were salt-spray tested to DIN EN ISO 9227 to determine the corrosion resistance. The result verified resistance to white rust for around 96 hours and to red rust for around 300 hours. Phosphating and yellow chromating rate considerably lower. Contrary to yellow chromated zinc surfaces whose corrosion-protective properties diminish when subjected to stressing by heat rising over +80 - +90°C, corrosion protection using a zinc-iron coating improves at temperatures of around +100°C. The galvanically applied zinc-iron layer is free of chromium VI and complies both with the RoHS Guideline and with the EU End-of-Life Vehicle Directive 2005/53/EC. A further advantage: The ball that forms the shut-off body within the valve is provided with hard chrome plating which significantly reduces the friction and wear on the ball seat. High-pressure ball valves are available for pressures of up to 800 bar.