Spiral wound gaskets have been proved to be one of most used gaskets especially at high operating pressure and critical applications. Such a gasket can withstand high temperature limit (550 °C) and pressure limit (250 bar).
Spiral wound gaskets are manufactured by specially formed metal strip and a soft gasket filler material such as graphite or PTFE. A “spring effect” characteristics gives grater resiliency under variying conditions. The metal strip provides outstanding recovery, while flexible filler guarantees excellent sealing.
The component expansion differences lead in combination with creep and setting processes to seal gap changes which occur due to the change in temperature and pressure during starting up and cooling down. The spiral wound gasket is able to balance this difference out due to its design, ensuring a secure seal even under these conditions.
A spiral wound gasket may include a centre ring and inner ring or both. The outer ring mainly centrers the gasket between flanges, while the inner ring provides strenghth and also reduces internal turbulences and protects the sealing element.
- DIMERFLEX ST10: spiral wound gasket without rings
- DIMERFLEX ST20: spiral wound gasket with inner ring
- DIMERFLEX ST30: spiral wound gasket with outer ring
- DIMERFLEX ST40: spiral wound gasket with outer and inner ring
- DIMERFLEX ST10Z: spiral wound gasket without rings and special PTFE sealing zone
- Metal materials for winding, inner and outer rings: The most commonly used metallic strips are SS316, SS316L, SS304, SS321, SS316Ti and Monel. SS316L, SS304, SS321 and SS316Ti are most often used for inner rings, but centering rings are usually made of carbon steel.
- Fillers: The most commonly used fillers are expanded graphite, PTFE, ceramic paper and mica.
- Standard thickness of SWG gaskets are from 2.5 mm up to 7.2 mm.