Background information

Although electroless nickel plating is known for the uniformity of the deposit, over very large items there can be slight thickness variations due to localised changes in temperature, activity, etc. The Vortoil Pipe is used on oilrigs, for the separation of crude oil from seawater. Understandably, the environment is very harsh and so a high degree of corrosion prevention is required, making electroless nickel a good choice. However, the nature of the operation means that the tolerances of the pipe must be less than 3 microns over the length.

What we did

The pipe, approximately 4m in length, needed to be electroless nickel plated internally and externally, including all the attached pipes, holes and fins. The deposit thickness required was 100 microns and the tolerance was < 3 microns variation in any area. While the size and material posed no problems generally, conforming to the tight distribution tolerances over that length, needed to be addressed. A jig was manufactured with a motor, which was attached to either end of the pipe. The pipe was then electroless nickel plated horizontally, while turning very slowly, like being on a spit.