5 – JOINTS FOR PROCESS PIPING SYSTEMS

The purpose of this chapter is to evaluate the type of joints that are most suitable. A piping system forms the arteries through which a process fluid flows, and this pipe connects the various pieces of equipment that are required, within a plant, to refine the product. To facilitate changes of direction and regulate the flow, these straight lengths of pipe must be connected to piping components, valves and process equipment, to complete the system. Numerous options are available to the piping engineer responsible for specifying the correct method of jointing for a particular process piping system. There are several alternatives for joints to be used within metal piping systems: flanged, butt weld, socket weld, screwed, hubbed connections, mechanical coupling, and soldered. All these methods have potential leak paths, and careful consideration must be made during the material selection process and choosing the level of inspection to minimize the “in-service” fluid loss.