ABSTRACT
Understanding the concepts of series and parallel corrosion is of vital importance in analyzing the corrosion processes that can become involved during or after hydrostatic testing (HYD) is completed. Anything that assists the "thermodynamically favorable" process of corrosion is undesirable. Factors such as poor welding (in welded parts), the use of maltreated water, inadequate materials selection, and so on could enhance the likelihood of corrosion occurring. When welding is done poorly, poor welding and post-welding treatment (PWT) will lead to the formation of platforms upon which corrosion can initiate (with or without HYD). It must be noted that although we have classified these risks into pre- and post-HYD, they are quite likely to cause both series or parallel corrosion failures. Another rather important issue that must be taken into account here is that the treatment policy for any corrosion resulting from HYD can have a tremendous effect on post-HYD costs.
