Graphite gaskets

Expanded graphite is valued as a sealing material for its compressibility, low permeability and ability to retain good properties over a wide temperature range.

Unlike many elastomer-bound materials, graphite does not rely on an organic binder for cohesion. Depending on the construction, it can therefore provide excellent in-service stability across many steam, chemical, petrochemical, power-generation and industrial maintenance applications.

Compatibility with strongly oxidising media and exact temperature limits must nevertheless be checked for the grade against the manufacturer’s data sheet.

Pure graphite

Expanded graphite sheet without metal reinforcement, suitable where high conformability is required and the mechanical conditions of the assembly permit it.

Nickel-reinforced graphite

Adding metal reinforcement improves mechanical strength and gasket handling.

Graphite with perforated/tanged stainless-steel insert

A common construction for industrial cut gaskets, combining the sealing behaviour of graphite with the rigidity and strength of stainless-steel reinforcement.

Graphite with flat stainless-steel insert

Some constructions use one or more flat stainless-steel inserts to reinforce the material and improve its mechanical behaviour.

European Sealing Technology supplies, among others:

• Eurograph;
• SIGRAFLEX® STANDARD;
• SIGRAFLEX® ECONOMY;
• SIGRAFLEX® UNIVERSAL;
• SIGRAFLEX® HOCHDRUCK.

SIGRAFLEX® STANDARD

Homogeneous high-quality flexible graphite sheet without adhesive or binder, impregnated to improve handling and reduce leakage.

SIGRAFLEX® ECONOMY

Flexible graphite reinforced with one or more thin stainless-steel inserts, suitable for pumps, valves and assemblies with low available seating stress, in accordance with manufacturer recommendations.

SIGRAFLEX® UNIVERSAL

Flexible graphite reinforced with a perforated stainless-steel insert for many pipe flanges and process equipment applications.

SIGRAFLEX® HOCHDRUCK

A multilayer construction with high mechanical strength for more highly loaded assemblies. SGL Carbon® documentation highlights process, heat-exchanger, steam and special joint applications.

Sheets can be supplied as received or converted into:

• standard gaskets;
• custom gaskets to drawing;
• segments for large sizes;
• special shapes;
• small batches or high-volume production runs.

For large sizes, gasket construction must be reviewed against the material, diameter and operating conditions.

Selection depends in particular on:

• pressure;
• temperature;
• fluid;
• oxidising nature of the medium;
• flange type;
• effective gasket width;
• available seating stress;
• emissions or compliance requirements.