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When it comes to applications involving aggressive chemicals, SIGMA/PTFE die cut gaskets provide enhanced levels of sealing performance when compared to conventional materials.

SIGMA /PTFE die cut gaskets are all capable of sealing from cryogenic temperatures up to 500ºF (260ºC), and suitable for sealing virtually every chemical medium across the entire pH range (0-14).

For intermittent use even higher temperatures can be tolerated. Pressures from 1232 psi down to vacuum can be accommodated, furthermore, application involving low gasket stress will not result in loss of sealing performance.

Typically these relate to the use of glass lined, plastic and ceramic flanges or operational conditions where flanges have become damaged or distorted.

The SIGMA/PTFE range of products has been engineered to be user friendly:

  • Materials can be cut easily using conventional tools and techniques
  • Complex geometric shapes can be accommodated, including narrow sections
  • Excellent dimensional stability
  • Non-stick properties offer excellent removal after usage to reduce the downtime of shutdown
  • All components in the SIGMA/PTFE range are FDA compliant
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    • 1. SIGMA 500

      MATERIAL: Biaxially orientated PTFE containing hollow glass microspheres

      COLOR: Blue

      Sheet material with higher compression specifically formulated for use on glass lined, plastic or ceramic flanges. Also suitable for use on flanges which are non-parallel, damaged or distorted. Compatible with acids and alkalis at all but the highest concentrations. Enhanced compressibility is achieved by the incorporation of hollow glass mirospheres as the inorganic filler.

      • Enhanced compressibility for low bolt loads
      • Improved flexibility over conventional calendered and graphite sheets
      • Moderate concentrations of acids & caustics, chlorine and hydrogen peroxide
      • Can be used for all concentrations of sulfuric acid
      • WRAS approved for hot and cold potable water services


    • 2. SIGMA 511

      sigma_511MATERIAL: Biaxially-orientated PTFE containing silica
      COLOR: Fawn

      Standard compression sheet material reinforced with a silica filler. Intended for use with concentrated acids (except hydrofluoric acid) and with most general aggressive chemicals: also suitable for medium concentrations of alkalis.

      • Standard compressibility
      • Strong acids (except hydrofluoric) to general chemicals
      • Can be used for all concentrations of sulfuric acid
      • Not suitable for molten alkali metals, fluorine gas or hydrogen fluoride
      • WRAS approved for hot and cold potable water services


    • 3. SIGMA 533

      sigma_533MATERIAL: Biaxially orientated PTFE containing barium sulfate
      COLOR: Off white (pigment free)

      Standard compression sheet material reinforced with barytes (barium sulphate) filler. SIGMA 533 is the preferred choice for sealing concentrated alkalis and is also compatible with Aqueous Hydrofluoric Acid. Restricted resistance to concentrated mineral acids.

      • Standard compressibility
      • Ideal for sealing food, pharmaceutical and other non-contamination applications
      • Strong alkaline solutions to other general chemicals
      • Aqueous hydrofluoric acid below 49%
      • Not suitable for sealing molten alkali metals or fluorine gas


    • 4. SIGMA 588

      sigma_588MATERIAL: Biaxially orientated PTFE
      COLOR: Off white (pigment free)

      Most compressible PTFE sheet without filler; biaxially orientated PTFE core with soft surfaces for higher, controlled compressibility.

      • Highly conformable surface layers designed for glass-lined, FRP, ceramic, plastic and low bolt load applications
      • Modified PTFE inner core design to maximize sealability and prevent blow-out
      • FDA compliant
    • 5. SIGMA 600

      sigma_600Developed specifically for petrochemical and chemical use. FDA compliant for both low and high bolt loads. Is non contaminating with lower creep an cold flow. A single gasket replacement for metallic and non-metallic flange applications.

      Designed to replace older conventional gasket technologies including skived PTFE, semi-restructured PTFE, and restructured PTFE. Its unique composition and uniform tensile strength make it a single gasket replacement material choice for both metallic and non-metallic flange applications like glass lined, ceramic, plastic or metal.

      • Max Temperature: 500°F (260°C)
      • Max Pressure: 1235 psig (8.5 MPa)
      • ASME m: 1.4
      • ASME y: 1595 psi (11 MPa)
      • pH Range: 0–14
    • 6. Fluoroseal Joint Sealant Tape

      fluorosealFluoroseal joint sealant tape is manufactured from 100% expanded PTFE. The material offers good creep and cold flow resistance.

      Fluoroseal possesses excellent chemical resistance. It is also weather resistant and will not deteriorate with age.

      The sealant tape is supplied with a self adhesive strip and is available in a range of widths from 3mm (1/8”) to 25mm (1”). It conforms easily to irregular shapes and can be pushed into narrow openings effortlessly.

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