PTFE envelopes are encapsulated flat seals and are used in flange connections that are exposed to high chemical stresses. Pure PTFE is the standard material but also modified PTFE and PTFE compounds can be used for higher requirements on pressure stability.
The advantages of PTFE-encapsulated seals are their outstanding sealing properties and their high chemical resistance. Additionally, they are suitable for fluctuating pressures and temperatures from -195 °C to +250 °C. Their main application is therefore in the chemical industry but they are also used in the food and pharmaceutical industry.
With PTFE-encapsulated seals, glass tubes and glass equipment in laboratories or pilot plants can be connected just as well as PTFE-enameled, coated or lined tubes and equipment in large-scale industrial plants.
PTFE-encapsulated seals are often used for flanges with planar sealing surfaces according to EN 1514-1 and DIN 2690.