Short answer
Inner tube damage in a steam hose may be associated with unsuitable service, temperature, condensate, the usage cycle or other causes. A definitive root cause is not determined from a single image. Inner surface findings, operating data and the manufacturer's examination must be assessed together.
Source: S036
Technical explanation
In steam service, findings such as blistering or tearing of the inner tube may be examined. Manufacturer guidelines draw attention to a mechanism referred to as 'popcorning', associated with the reheating of water remaining in the hose. Nevertheless, it is not correct to explain all internal damage by this name. Other possibilities such as the wrong hose type, high temperature, chemical exposure and mechanical strain are also assessed. Returning a damaged assembly to service just because its outer cover is intact is not a proper assessment.
Source: S036
Topic-specific checkpoints
| Item | Description |
|---|---|
| Finding | Inner surface blistering, tearing, hardening or other observation. |
| Location | Distance to the end and relationship to bends and flow direction. |
| Operating history | Steam type, temperature, pressure, shutdown and drainage. |
| Conclusion | Examining person/organization and the proven cause; estimates kept separate. |
Source: S036
How is it assessed in practice?
In the failure file, record the starting point of the damage and its distance from the connection. Removal and sampling should be carried out by an authorized method after safe removal from service. For example, if material torn from the inner surface is seen, the effect on the fluid path and downstream equipment must also be assessed by the facility. Together with the sample sent to the manufacturer, temperature/pressure records, shutdown practice and the cleaning method are shared. Keep the finding, the possible mechanism and the verified conclusion in separate fields.
Original editorial recommendation; not a clause of a standard.
Frequently asked questions
Is inner tube damage considered repaired if the hose is tested from the outside?
No. A test result does not eliminate the damage or restore the original performance. The decision on use is made through a proper technical examination and the product procedure.
Source: S036
Source coverage
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S036
Industrial Hose Safety Connections Gates · accessed 2026-10-19 PDF pp. 6–8 construction and selection; pp. 10–19 maintenance; pp. 21–27 special services