Spiral Wound Gaskets with Lines - Lined CLEANTIGHTв„ў - VALQUAВ® No. 8590L Series. These gaskets are composed of VALQUAFOILв„ў (expanded graphite sealing material) filler that has been wound in the middle of inorganic fillers. Features: Excellent heat resistance, Airtight. Temperature: -200 to 600oC/ -328 to 1,112oF, Pressure: Max 30.0 MPa