When welding pipe for a foam suppression system, is galvanic corrosion between the pipe and fittings a concern?

When welding pipe for a foam suppression system, is galvanic corrosion between the pipe and fittings a concern?

• A. True
• B. False
• C. Not applicable
• D. Depends on material compatibility

Answer: (A)

When two different metals are in electrical contact in the presence of an electrolyte, a galvanic cell forms and the more anodic metal tends to corrode. In a foam suppression system, moisture or foam concentrate can act as the electrolyte, and welding joints between pipe and fittings often involve dissimilar metals or compromised coatings. This creates a real risk of galvanic corrosion at those joints, especially in welded connections where heat-affected zones can change the corrosion behavior. So galvanic corrosion between pipe and fittings is a concern. To reduce the risk, use compatible materials for pipe and fittings, or employ dielectric/uninsulated joints, proper coatings, and ensured integrity of protective coatings and gaskets.

When two different metals are in electrical contact in the presence of an electrolyte, a galvanic cell forms and the more anodic metal tends to corrode. In a foam suppression system, moisture or foam concentrate can act as the electrolyte, and welding joints between pipe and fittings often involve dissimilar metals or compromised coatings. This creates a real risk of galvanic corrosion at those joints, especially in welded connections where heat-affected zones can change the corrosion behavior. So galvanic corrosion between pipe and fittings is a concern.

To reduce the risk, use compatible materials for pipe and fittings, or employ dielectric/uninsulated joints, proper coatings, and ensured integrity of protective coatings and gaskets.