PTFE Envelope Gasket

PTFE Envelope Gasket

PTFE envelope gaskets combine a PTFE outer envelope with an insert, providing corrosion resistance and resilience for chemical, pharmaceutical and food applications.

Structure

Envelope: PTFE provides corrosion resistance and a contact surface for clean media, including food and pharmaceuticals.

Insert: Commonly asbestos or non-asbestos rubber sheet, or graphite composite sheet, for compressibility, recovery and strength.

Performance

Resistance to most chemical media, except molten sodium and liquid fluorine.

Listed service range: -100°C to +260°C and 0.6–2.5 MPa.

Low friction eases installation and reduces adhesion; the source describes possible reuse.

Non-asbestos versions are described as suitable for food and pharmaceutical applications.

Application Examples in the Source

Chemical processing: A sulfuric-acid storage-tank flange is described as operating for 18 months without leakage and achieving three times the service life.

Food processing: Steam piping on a beverage filling line, with stable sealing at 120°C.

Power equipment: Transformer seals with aging resistance and a stated leakage rate of one-seventh that of conventional materials.

Precautions

Recommended long-term pressure is ≤2.5 MPa to limit PTFE creep.

Suitable flange types listed are full-face and raised-face steel pipe flanges.