Short answer
A hose must not be used as a tension member or a torsion spring. The end orientations and routing must be arranged so that no unwanted tensile or torsional load is transferred to the hose throughout the motion; minimum radius alone is not a sufficient check.
Technical explanation
Manufacturer assembly guides call for avoiding excessive tension, torsion and improper bending. A hose can change length or shape under pressure and motion; the installation must leave room for this. Even if a fitting's nut rotates, it cannot be assumed to absorb torsion during operation. Incorrect placement of supports can concentrate motion in a small area. Using the hose to carry a machine part creates a load different from its assembly function.
Topic-specific checkpoints
| Item | Description |
|---|---|
| Torsion | End orientation and reference line |
| Tension | Sufficient freedom throughout the motion |
| Support | Arrangement that does not concentrate the load at one point |
| Check | Evaluation of all operating positions |
How to evaluate it in practice
Observe the initial orientation using the printed layline on the hose or a safe reference mark. Include in the inspection plan whether the hose is stretched and whether the mark rotates in all permitted positions of the machine. The trial must be carried out within a safe commissioning procedure. If there is a problem, correct the end orientation, the supports and the plane of motion together rather than just fitting a longer hose. Instead of forcing the assembly onto the port, prepare a new, dimensioned routing.
Original editorial recommendation; not a clause of a standard.
Frequently asked questions
If the radius is acceptable, is the installation definitely correct?
No. Torsion, tension, support, rubbing and end loads must also be checked.
Source coverage
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S017
Parker Safety Guide, Publication 4400-B.1 Parker Hannifin · accessed 2026-10-20 PDF page 3; 3.7 Minimum Bend Radius, 3.8 Twist Angle and Orientation and 3.13 Routing | PDF page 3; 3.1 Component Inspection, 3.2 Hose and Fitting Assembly and 3.3 Related Accessories | PDF page 2; 2.8 Routing, 2.10 Mechanical Loads and 2.11 Physical DamagePDF page 3; 3.1 Component Inspection, 3.2 Hose and Fitting Assembly and 3.3 Related Accessories | PDF page 2; 2.8 Routing, 2.10 Mechanical Loads and 2.11 Physical Damage | PDF page 2; 2.2 Pressure | PDF page 2; 2.13 LengthPDF page 3; 3.7 Minimum Bend Radius, 3.8 Twist Angle and Orientation and 3.13 RoutingPDF page 2; 2.8 Routing, 2.10 Mechanical Loads and 2.11 Physical DamagePDF page 3; 3.1 Component Inspection, 3.2 Hose and Fitting Assembly and 3.3 Related Accessories
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S031
Hydraulics in Action: Maximizing Hose Lifetime Continental · accessed 2026-10-19 Optimizing Hose Routing for Longevity
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S039
Hose Handling Guide Penflex · accessed 2026-10-19 Installation recommendations; overbending; twisting; supporting hose