Thermiculite meets high temperature gasket challenge
A US petrochemical company faced a problem when an asbestos rope gasket in a gas turbine application, involving temperatures of up to 632 ยฐC and pressures of 0.33 bar, began to fail. However, Flexitailic came to the rescue with its new sealing material, Thermiculite.
Prior to contacting Flexitallic thc petrochemical company considered a number of non-asbestos alternatives such as rectal and semimetal gaskets, but these were rejected duc to very low loading on the flange. Exfoliated graphite was also considered; however, it is known to perform poorly in extended, continuous high temperature service due to thermal oxidation.
Following consultation and an assessment of the situation by Flexitallic engineers, a custommade Thermiculite segmented gasket was recommended. This design would enable engineers to remove a quarter of the casing, while leaving the bottom half ill place during repairs.
The Thermiculite gasket was manufactured in the UK and delivered to the US within the customer's deadline. It was easily and quickly installed :rod the joint successfldly sealed. Subsequently the joint was re-opened to repair the turbine's rotor, and the gasket remained leak-free.
Thermiculitc combines thermally and chelnically exfoliated vermiculite, a hydrated magnesium aluminium silicate. It is packed into a tanged 316 stainless steel core, creating a sheet sealing material that has the ability to perform in temperatures in excess of 42 l ยฐC.