Heating or cooling can be provided on tanks or pressure vessels by means of integrally welded dimple jackets which can be welded directly on any surface.  Pressures up to 200 PSIG & temperatures up to 650 degrees F can be provided for hot water, steam or hot oil applications.  Welded dimple jackets provide a means of cooling by cold water or glycol circulation, but are not recommended for rapid alternate cooling and heating cycles.  Material options are carbon steel or stainless.