Composite hose specifications hinge on four datasheet values read together: working pressure (typically 7–14 bar for EN 13765 builds, quoted at +20 °C and derated hot), vacuum rating (set by the inner wire, not the films), temperature envelope (commonly −30 °C to +80…+100 °C by liner), and minimum bend radius. Because the hose is a non-vulcanised stack of films, fabrics, and two wire helices, each parameter traces to a specific layer — which makes datasheets easy to misread if you don't know which layer does what. This deep-dive decodes every parameter and the tests behind it.
Quick answer: Read a composite hose datasheet as a system: WP 7–14 bar (EN 13765; LPG/LNG builds to EN 13766 reach up to 25 bar) with a 4:1 burst margin and 1.5 × WP proof test; vacuum capability from the inner wire helix — confirm the rating per DN; temperature by film material, with pressure derating above +20 °C; MBR roughly 4–6 × DN; and for flammable service, electrical continuity ≤10⁶ Ω verified per ISO 8031. Composite hose is never a steam hose.
This article is the parameter deep-dive of the composite cluster. For the step-by-step buying sequence, use the 11-point selection checklist; for procurement pitfalls, see what every procurement engineer must know.
Which Layer Delivers Which Specification?
A composite hose is an engineered laminate: an inner wire helix (galvanised, stainless, or polypropylene-coated) that supports the bore against vacuum and defines suction capability; multiple film plies (PP, PE, PTFE, PVDF) that form the chemical barrier and set the temperature/compatibility envelope; fabric plies that carry mechanical load; and an outer wire helix with an abrasion cover that provides hoop strength and impact protection. Swaged end fittings complete the pressure envelope — the assembly, not the hose body alone, carries the rating.
That mapping explains the datasheet: change the film and you change chemistry and temperature; change the wire and you change vacuum and crush resistance; change DN and you change pressure rating and MBR.
How Are Pressure Ratings Defined and Tested?
| Value | Typical figure | Basis |
|---|---|---|
| Working pressure (WP) | 7–14 bar (EN 13765 builds, at +20 °C) | continuous operating limit |
| LPG/LNG builds | up to 25 bar | EN 13766 |
| Burst pressure | ≥4 × WP | type test |
| Proof test | 1.5 × WP | every assembly, hydrostatic |
| Surge allowance | include water-hammer peaks in stated WP | buyer's input |
Two rules keep the numbers honest. First, WP is quoted at +20 °C and derates as temperature rises — polypropylene-lined builds lose a substantial share of their rating by +80 °C, so request the manufacturer's pressure–temperature correction data instead of applying the nameplate figure hot. Second, the proof test is hydrostatic: pneumatic pressure testing of composite hose is strongly discouraged because of the stored-energy hazard.
Working pressure also falls as DN rises within a family — never carry one figure across a size range.
What Does the Vacuum Rating Actually Depend On?
Vacuum capability comes from the inner wire helix, not the films. Many composite builds tolerate high vacuum, but the rating is specific to wire gauge, pitch, and DN — a DN 250 hose needs substantially heavier inner wire than a DN 50 to resist the same suction. Corrosion of the inner wire by the product is the classic hidden killer: a hose that passed its vacuum test new can collapse in service after the wire has been chemically attacked. Confirm wire material against the fluid, and state the required vacuum level explicitly in the specification.
What Temperature Envelope Can Each Liner Sustain?
| Film/liner | Indicative envelope | Typical duty |
|---|---|---|
| Polypropylene (PP) | ≈ −20/−30 °C to +80 °C | fuels, many acids/alkalis, general chemicals |
| Polyethylene/polyamide films | ≈ −30 °C to +65/+80 °C | petroleum products |
| PTFE | ≈ −40 °C (build-limited) to +100 °C+ | aggressive solvents, concentrated acids, aromatics |
| PVDF | ≈ −30 °C to +100 °C | chlorinated media, aggressive chemistry |
| LPG/LNG builds (EN 13766) | to ≈ −40 °C and below per certification | liquefied gases |
Chemical compatibility is temperature-coupled — always read the resistance chart at the operating temperature, not at ambient. And one hard boundary: composite hose is not a steam hose. Steam duty belongs to EN ISO 6134 hoses (type 1: 6 bar / 164 °C; type 2: 18 bar / 210 °C) with bolted safety clamps per EN 14420-3 / DIN 2817; hot water and thermal media near the film ceiling need explicit manufacturer approval.
How Do I Apply Minimum Bend Radius?
Composite hose is prized for flexibility, but the MBR is a hard mechanical limit — typically about 4–6 × DN depending on build (for DN 100, roughly 400–600 mm to the hose centreline). Below it, the wire helices deform: a single over-bend event can kink the hose, and a kinked composite hose is scrap, because the fractured wire compromises both pressure containment and vacuum resistance regardless of how minor the mark looks.
Design rules that protect the MBR in practice:
- Add ~20 % margin over the datasheet MBR when routing through confined bays, and model all articulation positions of loading arms and manifolds.
- Protect the first ~150 mm behind each swage collar — that flex zone concentrates bending; use bend restrictors on high-cycle duties.
- Support horizontal runs so sag does not translate into over-bend at the fittings.
What Electrical Properties Does the Datasheet Declare?
For flammable products and ATEX-classified areas (Directive 2014/34/EU), specify an electrically continuous assembly: the common acceptance criterion is end-to-end resistance ≤10⁶ Ω including fittings, measured per ISO 8031, verified at manufacture and re-checked after any fitting change and before campaigns. Electrically insulating builds exist for cathodic-protection-sensitive interfaces (e.g. ship-to-shore) — continuity is a specified choice, not a default, so state which behaviour the installation requires. Site bonding and earthing follow IEC 60079-32-1.
Which Standards Govern, and What Do Certificates Prove?
- EN 13765 — thermoplastic multi-layer (non-vulcanised) hoses and assemblies for hydrocarbons, solvents and chemicals; defines types by duty severity (Type 2 commonly specified for petroleum products, Type 3 for chemicals), test pressures, electrical requirements, and marking (DN, WP, type, manufacture date, standard number).
- EN 13766 — the composite-hose standard for LPG and LNG transfer.
- EN 1765 — rubber oil suction and discharge assemblies for marine transfer: relevant context at terminals, but it is a rubber hose standard; composite assemblies certify to the EN 13765 family, with OCIMF operational guidance often imposed contractually at marine berths.
- ATEX 2014/34/EU + ISO 8031 + IEC 60079-32-1 — the explosive-atmosphere framework, the resistance test method, and electrostatics practice respectively.
- EN 10204 3.1 — material certificates for end fittings, standard contract language in chemical service.
A compliant delivery carries the type-test certificate for the actual configuration, the individual assembly's 1.5 × WP hydrostatic certificate keyed to its serial number, fitting material certs, and a resistance result for conductive builds.
What Do the Failure Modes Trace Back To?
Three dominate. Fitting-zone failure — under-specified swage or corroded ferrule; the interface is the highest-stress region, which is why assembly-level testing is non-negotiable. Inner-wire collapse under vacuum — usually chemical attack on the wire, invisible externally until the bore flattens. Ply delamination — thermal cycling beyond the film rating; progressive and hidden until late, which is why the periodic hydrostatic test matters even when the hose looks sound. Inspection practice: visual check before use, hydrostatic re-test at 1.5 × WP on a 6–12-month cycle per site procedure, resistance re-test for conductive types, and immediate retirement on any kink, wire corrosion, or fitting movement.
Cost: Which Specification Choices Drive Price?
Liner material is the largest lever — a PTFE-film build in DN 100 costs a multiple of the PP equivalent, so specifying PTFE where PP is chemically adequate wastes CAPEX, while under-specifying PP into solvent duty guarantees early failure and higher OPEX. Fitting alloy is second: stepping from carbon steel to 316L adds meaningfully to assembly cost but is mandatory for acids and chlorinated media. Against these, composite's ~40 % weight saving versus rubber at DN 150 lowers handling effort and strain injuries on loading bays — and on a bay where downtime costs hundreds to thousands of EUR per hour, one avoided release outweighs the entire specification premium.
Check the Numbers Against Stock
Compare liner and DN options in industrial hoses, search directly for composite hose, or pull manufacturer datasheets from the catalogue library. If the pressure–temperature correction, vacuum rating, or ATEX documentation for your duty needs validating, contact our engineering team — we configure the assembly, swage and hydrostatically test it at 1.5 × WP, and deliver it with the complete certificate package.