Graphite gaskets

Expanded graphite is used in production of flat gaskets and packings. This material is produced in a special process where natural graphite is expanded under extremely high temperatures after mixing with chemicals. After removing the chemicals again, the expanded flakes are then pressed into sheets or rolled to a defined density of, e.g. 0.7 or 1.0 g/cm3.
The foil may be used as filler material in spiral wound gaskets or as a seal in serrated gaskets.

The temperature range is –200°C to +450°C.
This packing has excellent chemical resistance and has neither cold nor hot flow. As the material is already millions of years old, it has no ageing problems.

Graphite with steel layer (graflam)

The sheets are often pressed together with a metal insert.
This strengthens/stabilises the gasket so that it may be adjusted and fitted without being damaged. The insert is usually made in S316 stainless steel or nickel. When using two S316 stainless inserts, these will usually have a thickness of 0.05mm each or 0.013mm when using nickel inserts.
The inserts are bonded to the graphite.

Tanged (Perforated layer in S316)

A tang core is used more and more as an insert and consists of a 0.10mm thick S316 stainless steel insert that is not bonded. The steel core is perforated and has small sharp teeth that stick into the graphite and give a robust easy-to-use gasket. We do not recommend manual cutting of this gasket, as this may give a poor and sometimes dangerous results. Vestpak AS always water cuts tanged materials.

For further technical specifications Sigraflex®