CBE Stripping and Replating ENP on 42” Valve Balls

Several 42” valve balls in critical service in Europe required refurbishment after extended use in a hostile environment.

The Situation

Several 42” valve balls in critical service in Europe required refurbishment after extended use in a hostile environment. Their original Electroless Nickel Plating (ENP) had worn away, requiring the components to be stripped and replated.

Manufactured from 316 stainless steel, the valve balls offered excellent corrosion resistance but required careful handling during ENP removal to protect the substrate.

The Technical Approach

ENP stripping is not a one-size-fits-all process. The correct method depends on the base material.

For ferrous alloys, CBE+ uses a specially formulated alkaline solution that gradually dissolves the nickel while protecting the substrate and forming a passive protective layer.

Stainless steels such as 316, Inconel and Super Duplex can generally be treated using controlled nitric acid exposure. However, the exact alloy must always be confirmed, as different stainless grades can behave differently.

Other materials require different approaches. Aluminium can be stripped using carefully controlled nitric acid, while copper and brass require particularly precise treatment. CBE+ can also remove zinc, chrome and galvanising coatings as part of its refurbishment services. Shot blasting is another option where surface finish and dimensional tolerances allow.

The Result

The 316 stainless steel valve balls were successfully stripped using a controlled nitric acid process without damaging the substrate. A new ENP coating was then applied, restoring the required corrosion resistance and surface properties.

By stripping and replating rather than replacing the components, CBE+ extended their service life, reduced waste and provided a cost-effective refurbishment solution for demanding operating conditions.