PTFE Hose

PTFE unique properties:

- Excellent chemical resistance. It does not dissolve or swell in any of known solvents. It is resistant to highly aggressive acids and bases. Only very few, very rare substances (fluorine, boiling alkali metals, oxygen bifluoride, chlorine trifluoride) can affect PTFE.
- Wide range of thermal resistance. PTFE remains flexible even at the temperature of liquid helium (-269°C).
Crystalline melting point of PTFE is +327°C, and at +415°C decomposition of PTFE takes place. Working temperature for hoses made of PTFE usually ranges from -70°C up to +260°C depending on the hose design (pressure and mechanical parameters of PTFE start to decrease when the temperature rises above +130°C).
- Resistance to ageing and weather conditions. PTFE is hydrophobic, entirely resistant to ozone, oxygen, light and UV radiation. Samples exposed for several dozen of years to diverse climate conditions have not shown any changes to PTFE properties.
- PTFE has a very low coefficient of friction (from 0.02 to 0.2) and a low value of surface energy. Therefore hoses made of PTFE have self-cleaning properties (substances do not stick to hose walls) so the transfer is very hygienic.
- Good electrical properties, high resistivity.
- Self-extinguishing properties.
- Moderate resistance to abrasion.

Other materials similar to PTFE

Hoses can be manufactured not only from PTFE but also from PTFE copolymers. They usually feature high chemical and thermal resistance but other properties are slightly different in comparison to PTFE (better mechanical resistance, better processing qualities):

- FEP (teflon FEP, DuPont),
- PFA, MFA (teflon PFA, DuPont),
- ETFE (Tefzel, DuPont),
- ECTFE (Halar).

Production and construction of PTFE hoses

Because of high viscosity even at temperatures close to thermal decomposition (+415°C), PTFE hoses are manufactured by extruding the compound of lubricant (paraffin oil) and PTFE powder.

Types of PTFE hose construction:

- Smooth and corrugated hoses with no braid. Used for low pressure applications. Translucent, PTFE wall allows the visual control of the flow.
- Smooth hoses with a single or double external braid made of stainless steel. Widely used for almost all media: chemicals, gases, steam, oils, lubricants, fuel, paint, adhesives, foodstuffs in all branches of industry. The combination of relatively high working pressure of the hoses (up to around 400 bar) and PTFE unique properties
result in a universal and irreplaceable solution for recent industrial technology.
- Corrugated hoses with external braids made of stainless steel or different materials. Sometimes reinforced with a steel wire helix between PTFE and the external braid. Manufactured in various construction options with lower working pressure but higher flexibility than smooth bore hoses.
- Smooth bore hoses with an extruded PTFE liner with a textile braid, steel wire helix reinforcement and an external layer made of rubber. All layers are vulcanized and permanently integrated with the PTFE internal layer - as in a standard rubber hose. Used mainly in chemical industry.