Gasket→PTFE Gasket
Filled PTFE Sheet Gasket - Flexitallic Sigma
Sigma has unique biaxial fibrillated structure and excellent dimensional stability, and maximum reduction in creep and stress relaxation of PTFE by combining these fillers. The PTFE material has excellent chemical resistance (pH 0 ~ 14) and good cleanliness can be widely used for alkali and corrosive fluids, very suitable for food, medicine, electronics (except hydrofluoric acid), and pressure range from vacuum to 8.5MPa. SIGMA sheet gasket is softer and lower stress requirement than pure PTFE, it can be used in glass lined, plastic, ceramic flange; and good sealing performance to slender or damaged flange surface, or low loading conditions.
Product Sigma 500 Sigma 511 Sigma 533 Sigma 600
Color Blue Fawn Off-White White
Filler hollow glass microspheres Silica Barium Sulfate None
Max. Pressure (bar) 85 (1.5mm), 80 (2.0mm), 75 (3.0mm)
Service Temperature (°C) -200 ~ 260
Density ASTM F1513(g/cm3) 1.40 2.2 2.9 0.75
Compressibility ASTM F36 (%) 35 7 8 68
Recovery ASTM F36 (%) 44 44 43 5
Tensile Strength ASTM F152 (Mpa) 14 15 15 6.7
Residual Stress(175°C)
DIN52913 (Mpa)
30 30 28 34
Creep Relaxation ASTM F38 (%) 31 35 33 <50
Liquid Leakage ASTM F37 (mL/hr) 0.7 1.8 1.8 1.2
Gas Leakage DIN3754 (mL/min.) 0.02 0.01 0.01 0.01
Application Low bolt loads,
Improved flexibility,
Suitable for use in alkali, acid and chlorine service,
WRAS approved for potable water,
Glass lined, plastic and ceramic flange
Strong acids
(except hydrofluoric),
Suitable for oxygen & peroxide,
WARS approved potable water
Strong alkalis,
Aqueous hydrofluoric acid <49%,
Ideal for sealing food, pharmaceutical and non contamination application,
Not suited for sealing molten alkali or fluorine gas
Universal mis-application, minimized inventory,
High compressibility for ultra-low bolt loads,
A wide range of chemical media; acids, alkalis, halogens and hydrocarbons,
For contamination sensitive,
Plastic and glass lined equipment
  ZEN WANG Co., Ltd.
‧Add:No. 20, Heye 2nd Rd., Daliao Dist.,
Kaohsiung City, Taiwan, R.O.C. Post Code: 831130.
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