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
SIGMA 533
SIGMA 588

MATERIAL: Biaxially orientated PTFE containing barium sulfate
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.

MATERIAL: Biaxially orientated PTFE
Most compressible PTFE sheet without filler; biaxially orientated PTFE core with soft surfaces for higher, controlled compressibility.
SIGMA 500
SIGMA 511

MATERIAL: Biaxially orientated PTFE containing hollow glass microspheres
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.

MATERIAL: Biaxially-orientated PTFE containing silica
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.
SIGMA 600

Developed 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.
Fluoroseal Joint Sealant Tape
Fluoroseal 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.