|
You must sign in to view this presentation.*
*By signing in and accessing the video, you agree to the terms and conditions of this site.
During the winter of 2013-2014, Northern California experienced unusually cold temperatures. Low temperatures delayed Pacific Gas & Electric's (PG&E) painting operations on new and old pipelines. Their current specifications only allowed the application of epoxy coatings down to 50°F. Coatings capable of being applied at or below 50°F were untested and PG&E preferred to control the environment over changing the approved products. The use of small huts over the application area proved to be expensive and time consuming and they looked for a novel method of temperature control.
Heat induction proved to be the most efficient and controlled way to heat the substrate prior to application and to cure the coating after application. Heat induction is the process by which a conductive metal is heated using coils of electromagnets with alternating current. The alternating current produces eddy currents within the substrate and internal resistance produces heating. The heat produced is well controlled and in a localized location, allowing for surrounding coating to remain undamaged. Laboratory studies showed the heat induction was capable of quickly raising and maintaining elevated surface temperature that improved cure time and overall working time on each girth weld.
|
