What voltage requirement does SP0176 specify for cathodic protection?

The correct voltage requirement specified by SP0176 for cathodic protection is a minimum of 850mV. This standard reflects the necessary potential to ensure that a structure, such as a pipeline or tank, is adequately protected against corrosion. A potential of at least 850mV indicates that the metal structure is in a sufficiently negative state relative to a reference electrode, usually a copper/copper sulfate electrode, to effectively minimize corrosion rates.

This threshold is established based on extensive research and field data showing the correlation between the potential measurement and the degree of corrosion control achieved on various types of metals in different environments. This requirement is crucial for maintaining the integrity and longevity of metallic structures exposed to corrosive environments.