Construction and Measured Properties

SIGMA 600 is an unfilled, pigment-free PTFE. Featuring 68% ASTM F36 compressibility and 5% recovery, it differs significantly from the denser PTFE grades in the product line. Per Flexitallic testing: 68% compressibility, 5% recovery, and a density of 0.8 g/cm³. For a 1.5 mm thickness, published technical literature indicates an ASME m-factor of 1.4, a minimum seating stress (y) of 11 MPa, and an EN 13555 Qmin/0.01 value of 15 MPa. ASTM F38 creep relaxation is rated at less than 50%. These parameters are derived from specific standardized test methods and do not represent universal assembly criteria.

Applications and Service Conditions

Manufacturer data sheets recommend this material for low bolt load applications, specifically glass-lined or plastic-lined equipment and contamination-sensitive processes. Published technical data rates the material up to 260°C, with maximum pressure ratings of 85 bar at 1.5 mm, 80 bar at 2 mm, and 75 bar at 3 mm. These upper limits must not be applied concurrently without consulting the pressure/temperature (P/T) curve.

Comparing Materials Without Assuming Equivalence

Compare with microcellular or expanded PTFE grades only after conducting a thorough flange rigidity analysis. High compressibility does not equate to unlimited pressure containment or creep resistance. To facilitate an engineering evaluation, please specify the media, chemical concentration, flange rating/class, available bolt load, and required nominal thickness.

Additional technical sheets to consider: Garlock GYLON 3540 and Durlon 9645. These are structural construction comparisons.