Spiral-wound gaskets have long been used as sealing elements in refineries, chemical plants, gas installations, water treatment plants and in general pipeline construction.
Spiroflex gaskets SpV retain the same filler strip throughout. Common filler materials include graphite, sintered or unsintered PTFE and mica. Spiroflex gaskets SpV are only suitable for flange connections below PN 25 where there are sufficiently high bolt loads available.
BAM test report: Profile SpV with graphite for liquid and gaseous oxygen 350 °C, 250 bar (Manufacturer certificate on the basis of a BAM test report).
Spiroflex gaskets with sealing zone Profile SpZ have the same filler strip inside and outside and a PTFE filler strip in the middle area. They have a number of distinct technical advantages:
» Lower seating stress required with higher leak-tightness, as the surface pressure is concentrated on the middle area of the sealing zone of unsintered PTFE. This allows Profile SpZ gaskets to be used from PN 10. The minimum surface pressure is 30 N/mm² as opposed to the 50 N/mm² otherwise required.
» The surface pressure creates smaller radial forces than for example gaskets that are filled entirely with PTFE. There is therefore no need to support the spiral with an inner ring at smaller nominal diameters up to max. DN 200 and at low sealing pressures of approx. 60 N/mm². High pressure and/or frequent load changes require a high sealing pressure, in this case the spirals should be supported with an appropriate flange design or additional rings.
» As the PTFE sealing zone is protected by areas filled with graphite, it can withstand extreme operational conditions.
» Using a helium leak detector, leak rates of 10-8 mbar I s-1 m-1 have been measured on SpZ gaskets DN 150 with PTFE sealing zone.
Spiroflex gaskets SpFS in the “Firesafe“ range have unsintered PTFE filler strips on the inside and graphite filler strips on the outside. They are suitable for applications where the product may not come into contact with the graphite and in an operating temperature range below 250 °C. At temperatures above 250 °C which require to be “Firesafe“, Spiroflex gaskets SpV with graphite filler band can be used
Enclosed you will find downloads such as product documentation, product data sheet, safety information and gasket characteristics.