1 - General Information

Abstract

This chapter offers information on various products used in pipelines industry and offers some tips and suggestions on their uses. Guys are wire ropes or strands used to hold a vertical structure in position against an overturning force and the most common types of guyed structures are stacks, derricks, masts for draglines, reversible tramways, and radio transmission towers. While constructing offshore pipelines, the most likely place for a buckle to occur during the lay operation is in the sag bend just before the pipe touches the bottom. A gauging pig can be placed inside the pipe and pulled along the pipe. If the lay barge moves forward and the pig encounters a buckle or dent, the pull line will become taut. This indicates that it will be necessary to pick up and replace the dented section of the pipe. After construction, the pipeline bore typically contains dirt, rust, and millscale, which have to be cleaned off to prevent contamination of the product, to allow effective use of corrosion inhibitors during commissioning and operation, and to improve the flow efficiency. A typical cleaning operation would consist of sending through a train of pigs driven by water. The pigs would have wire brushes and would permit some bypass flow of the water so that the rust and millscale dislodged by the brushing would be flushed out in front of the pigs and kept in suspension by the turbulent flow.