ABSTRACT
Polysiloxane is an inorganic polymer chemistry with superior properties including temperature tolerance and UV resistance in comparison to organic type polymer chemistries. New R&D efforts in ambient cure, third generation, polysiloxane technology eliminate existing issues of post cure polysiloxane coatings, including low film hardness, anti-corrosion properties & weathering resistance prior to post curing >300 °F.
Recent R&D efforts in polysiloxane matrix spray-on insulation have resulted in ultra-high-build and higher temperature capabilities to 400 mils DFT per coat and 750 °F respectively, producing results which exceed limitations of current spray-on insulation materials.
Laboratory testing of these polysiloxane based materials confirms much higher temperature tolerances than acrylic spray-on products and insulation performance nearly equal to traditional block, batt and mat-type insulation materials.
INTRODUCTION
Insulation is an integral part of petroleum refineries and chemical plants. The shiny sheet metal jacketing of insulated pipework and vessels is probably second only to large storage tanks as an iconic image of the typical petroleum refinery, but it gives two mistaken impressions. The first is that the three-step insulation system of corrosion resistant coating, pieced-together insulation and pieced-together shiny metal jacketing is the best way to insulate elevated temperature equipment; the second is that the shiny metal jacketing does not allow water ingress, the insulation beneath does not absorb and hold water, and the CUI coating beneath the insulation is successfully resisting corrosion.
Another, less-noticeable form of insulation in refineries and chemical plants is spray-on, most frequently used for product temperature stability on the exteriors of large storage tanks, and for personnel protection in areas where plant workers might come into contact with hot operating equipment. Since the surface of spray-on insulation is often topcoated with a protective, UV resistant finish coat, most spray-on insulated surfaces are identical in appearance to coated, uninsulated surfaces and thus go unnoticed.
Insulation is used to for process stability assurance, for energy conservation, for personnel protection and for a host of other reasons. The two primary sets of standards dealing with insulation in petroleum and chemical processing are NACE SP 0198-2017, Standard Practice, Control of Corrosion Under Thermal Insulation and Fireproofing Materials—a Systems Approach1, and API RP 583, Corrosion Under Insulation and Fireproofing2. Both NACE SP 0198 and API RP 583 implicitly assume that for service temperatures above 300 °F, block or fibrous insulation topped with sheet metal jacketing must be used.
