Short answer
The outer braid of a metal hose is part of the design for carrying the loads that arise under pressure. The number of braid layers does not on its own determine the pressure rating; the body, diameter, material, temperature, end assembly and manufacturer table must be read together.
Technical explanation
Braided and unbraided versions of a corrugated body may have different operating limits. Whether the braid can perform its function depends on it being manufactured correctly together with the ends. Wire breakage, displacement of the braid or heavy abrasion are significant for assembly integrity. An additional braid layer does not mean that the permissible pressure can be increased by a simple factor. Temperature derating must also be taken from data specific to the metal grade and the product.
Topic-specific checkpoints
| Item | Description |
|---|---|
| Number of braids | Not a pressure calculation on its own |
| Body series | Corrugation geometry and material |
| Temperature | Product-specific permissible limit |
| Assembly | Joint verification of braid and end fitting |
How is it assessed in practice?
On the purchase form, write the body series, diameter, fluid temperature and assembly limit next to the term 'double braid'. When comparing two manufacturers' products, do not equate them by braid count alone. Do not create a pressure upgrade method by sliding an additional braid over the existing one in the workshop. If a protective outer sleeve is used, plan in advance how the braid will be inspected. In acceptance on delivery, keep the inspection records for the braid ends, the weld zone and the hose routing separate.
Original editorial recommendation; not a clause of a standard.
Frequently asked questions
Does a second braid layer double the pressure?
No such general ratio can be used. The permissible value is taken only from the manufacturer data for the product and assembly concerned.
Source coverage
-
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
-
S039
Hose Handling Guide Penflex · accessed 2026-10-19 Installation recommendations; overbending; twisting; supporting hose