Short answer
The choice between smooth-bore and convoluted PTFE hose is not made on the basis of flexibility alone. Flow and cleaning requirements, bending space, permeation, pressure and fitting construction are evaluated together; each series has its own limits.
Technical explanation
The inner surface geometry affects the path the fluid takes and the cleaning approach. Smooth bore and convoluted construction are different product designs; the manufacturer's external reinforcement and fitting options change the outcome. A PTFE inner tube does not mean that the entire hose assembly will be suitable for every temperature and fluid. Antistatic properties must be stated separately. A metal-braided appearance alone does not provide information about the electrical behavior of the inner tube.
Topic-specific checkpoints
| Item | Description |
|---|---|
| Inner surface | Smooth-bore or convoluted product design |
| Flow | Viscosity, flow rate and pressure loss |
| Cleaning | Residue and applicable method |
| Assembly | Ends, braid and motion limits |
How is it assessed in practice?
When comparing two candidates for a viscous product line, ask not only about the expected pressure loss but also about residue removal and cleaning conditions. For a moving machine, send the end positions and the minimum radius with a drawing. Do not merge different manufacturers' series under the same PTFE name into a single data row. Ask for the test and application data of the product concerned without turning the advantages of the inner surface geometry into a firm guarantee of flow rate or cleanability.
Original editorial recommendation; not a clause of a standard.
Frequently asked questions
Is smooth-bore PTFE hose always less flexible?
This cannot be generalized to all products. Flexibility must be compared according to geometry, wall, reinforcement and the manufacturer's design.
Source coverage
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S024
Hose and Flexible Tubing, MS-01-180 Swagelok · accessed 2026-10-19 PDF pages 4–5 / printed 253–254: Nomenclature; pages 8–9: selection, installation and use
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S040
Smoothbore PTFE hose Aflex / Watson-Marlow · accessed 2026-10-19 Construction; antistatic liner; use limitations