PRCI has sponsored significant research to support maintenance and in-service repair welding, including hot-tap welding. The knowledge gained in this research provided the point of departure for the application of this time and cost saving approach to the chemical pipeline industry. Safe and efficient in-service welding of chemical pipelines reduces operating costs by avoiding pipeline shutdowns for maintenance/repair welding. If safe operations can be demonstrated, these applications can be utilized across the chemical industry on a routine basis.
Our understanding of this technique has identified three adverse effects that may happen when welding on in-service pipelines: burn-through, thermal cracking and decomposition of the product. The first two effects have been researched thoroughly in the past. The third effect, the decomposition of certain refined products, such as butadiene, propylene and ethylene has been addressed in this PRCI research project.
From the research effort, criteria for in-service welding were developed for a wide range of chemicals that were identified as being of interest. For ease of application, the format for these criteria is similar to that used for material safety data sheets (MSDS).
As of September 2009, the research is complete on this project. The Final Report (MATR-3-2) is currently is under review by the Project Team.