Semi-metallic gaskets
Semi-metallic gaskets are combinations of suitable metals in connection with graphite, PTFE, mica, rubber or other sealing materials.
Advantage: Functional separation of "supporting" and "sealing".
Depending on the operating conditions spiral wound gaskets, enveloped or jacketed gaskets, grooved profile gaskets with layers (CAM-profile), corrugated gaskets, rubber-steel gaskets, are used preferably in the main or high load application.
Product range:
- Spiral-wound gaskets
- Metal jacketed gaskets
- Camprofile gaskets
Spiral-wound gaskets are suitable across a wide range of fluctuating service pressure – up to 250 bar – and temperature – from -200°C to 1000°C – depending on their construction. The sealing element consists of a V-shaped metal strip spirally wound in combination with a soft sealing material filler. The metal strip provides outstanding resilience, while the flexible sealing filer guarantees excellent sealing. An outer metallic guide ring, when present, serves to locate the spiral element centrally on the flange faces, to prevent blow-out and, acting as a compression limiter, to prevent overloading of the sealing element. An inner metallic ring, when present, prevents radial flow (buckling) of soft the filler, minimises flow resistance and crevice corrosion, acts as a heat shield in presence of high temperature.
Metal Jacketed gaskets, as the name suggests, consist of a metallic outer shell with non-metallic filler. The filler material gives the gasket resilience, while the metal jacket protects the filler and resists pressures, temperatures and corrosion. Metal Jacketed gaskets are available in a wide range of sizes and configurations. They are traditionally used for heat exchanger applications, pumps and valves, however the resilience and recovery properties of these gaskets are limited. Metal Jacketed gaskets require smooth flange surface finishes, high bolt loads and flange flatness in order to seal effectively.
Camprofile gaskets consist of a metal core (usually stainless steel) with concentric grooves on either side, topped by sealing materials. Depending on the service, the sealing layers are typically graphite or PTFE. Camprofiles have a very wide seating stress range, which makes them highly suitable for varying temperature and pressure services, for light as well as heavily constructed flanges. Other benefits of camprofiles are very low leakage rate, due to the minimum thickness of the sealing layers, low sensitivity to essembly faults, and the possibility to re-use the metal cores after cleaning.
