This particular transformer requires static head pressure at 1-2 psig of nitrogen to provide a buffer of inert gas to keep out atmospheric contaminates. They were unable to keep the static pressure due to the ongoing leaks on the main head so they were feeding additional N2 from portable bottles which was not ideal due to cost and safety.
We installed (2) layers of 1″ wide x 1/4″ thick Gore Gasket Tape Series 500 on top of one another to achieve the desired thickness to overcome the raised ID flange surface lip (~.180″ high) and the OD edge raised scallops (.140″ high) that caused us to use more than just the one layer of .250″ thick tape. We would not have had enough compression on the single layer due to the raised flange surface lips.
A team of 6 people worked for 10 hours to disassemble, prep, install Gore Gasket Tape Series 500 (2 layers), position a 6’ x 12’ head plate with crane, install 68 fasteners and follow exact torque specifications on tightening down the head plate.
The install was a huge success! The customer has been trained on using the Gore Gasket Tape Series 500 and has continued to solve additional reliability issues with Gore ePTFE Sealant products.