Insulation Gasket
Flange isolation gaskets and isolation kits are used throughout the world and in numerous cathodic protection industry applications. Flange isolation kits have a proven track record for being one of the most effective and reliable products for controlling and maintaining the integrity of piping and tank systems under demanding conditions. Isolation gaskets (Flange Insulating Kit) are used to stop the current flow across metallic pipelines by separating two flanges. The isolation of these pipeline segments allows cathodic protection for underground and above ground pipelines to control the stray electric current flow.
Type D (API Ring Joint) – 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 E (Full Face) – 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 F (Ring) – 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.
