PTFE Envelope Gaskets

Overview

PTFE envelope gaskets are composite gaskets consisting of a PTFE outer envelope and an internal inlay. The PTFE layer provides excellent chemical resistance, while the inlay supplies mechanical strength, dimensional stability, and improved pressure resistance.

Design & Construction

• Outer envelope made of virgin or modified PTFE
• Internal inlay for strength and resilience
• Designed primarily for flange sealing applications
• Prevents direct contact between process media and inlay material

Inlay Materials

• Compressed non-asbestos fiber
• Elastomer-bound fiber
• Metallic inlays (upon request)

Key Properties

• Excellent chemical resistance due to PTFE envelope
• Wide operating temperature range (depending on envelope and inlay)
• Good pressure resistance supported by inlay material
• Low permeability and contamination-free sealing

Performance Characteristics

• Suitable for chemically aggressive media
• Provides reliable sealing under fluctuating operating conditions
• Maintains integrity where standard soft gaskets may fail

Applications

• Chemical and petrochemical industry
• Process industry
• Pharmaceutical production
• Food and beverage industry
• Systems where media contamination is not permitted

Food & Safety Compliance

• PTFE is physiologically inert
• Suitable for direct contact with food
• Complies with FDA requirements for food applications

Advantages

• Combines chemical resistance with mechanical strength
• Prevents process media contamination
• Wide compatibility with aggressive chemicals
• Long service life compared to conventional soft gaskets

Notes

• Maximum pressure and temperature depend on inlay selection
• Proper installation torque is essential to avoid PTFE cold flow
• Recommended for applications where standard gaskets are unsuitable