Flange Insulation Gasket Kit
The Flange Insulation Gasket Kit is the most widely used form of controlling losses due to corrosion. Flange Insulation Gasket Kits can be used to control stray electric currents in piping at oil, gas, water, refinery, and chemical plants to increase the effectiveness of cathodic protection systems and confine or eliminate electrolytic corrosion.
Type F Gaskets
Type F gaskets are designed to fit the raised face portion of flanges. The outside diameter of the gasket is slightly smaller than the inside diameter of the bolt hole circle. The outside diameter is designed for alignment by the insulating sleeves. The central gaskets are available in the same materials as Type E. Upon installation, it is recommended that tape be wrapped around the outside of the flange to prevent foreign material from lodging between the exposed portions and causing "shorting out" of the flanges.
Type E Gaskets
Type E gaskets are designed for full protection of flanges, and have the same outside diameter as the flange. Each gasket has precision-located bolt holes. Upon installation, it is recommended that tape be wrapped around the outside of the flange to prevent foreign material from lodging between the exposed portions and causing "shorting out" of the flanges. All Type E gaskets are easily centered with the flange inside diameter. Gaskets with slightly larger outside diameters are available on request.
Type D Gaskets
Type D gaskets are insulating ring joint gaskets made to fit the ring groove of Ring Type Joint flanges. The Type D central gasket is made of medium weave fabric-reinforced phenolic, manufactured to ASA (ANSI) gasket dimensions. Properties are similar to those of phenolic flat central gaskets and are available in the basic octagonal shapes. Oval shapes can be ordered by special request. When installing Type D gaskets, it is also recommended that tape be wrapped around the outside of the flange to prevent foreign material from lodging between the exposed portions and causing "shorting out" of the flanges. Alignment pins should be used whenever possible to assure proper alignment of flanges when installing all flange insulation sets. Pins should be a minimum of 3/32" (2.38mm) larger than the bolt size.
Type O Gasket Kit
Type O Gaskets have a sealing element on each side of the gasket and are available in both Type E and Type F styles. The sealing element materials are Nitrile, Viton, or Teflon®. Type O Gaskets are made of both phenolic and G-10 materials.
Suggested Flange Isolation Material Compatibility