Thermoplastic hoses in paint and solvent applications

Technical explanation

Chemical compatibility is checked separately for the contacting inner tube, seals and metal fittings. Paint transfer and solvent flushing can create different exposures. Effects such as permeation and swelling can affect function before any visible leak occurs. In a system using a flammable fluid, the electrical properties of the hose, the fittings and the facility's risk assessment must be considered together. A chemical resistance chart does not replace application-specific approval of the entire system.

Source: S017, S020, S024

Topic-specific checkpoints

Source: S017, S020, S024

How is it assessed in practice?

For a paint line with product changeovers, list the production fluids and all flushing steps. Add concentration, temperature and contact duration for each substance. Also record wiping the outside of the hose with solvent as a separate exposure. If a sample trial is needed, tie it to a safe test plan defined by the supplier; do not use the running line as a test rig. Ask for the compatibility response to state clearly the seal and fitting materials as well as the hose code.

Original editorial recommendation; not a clause of a standard.

Frequently asked questions

Is a solvent-resistant inner tube sufficient?

No. The fitting and seal are also exposed to the fluid; in addition, pressure, permeation, cleaning and electrical requirements must be evaluated.

Source: S017, S020, S024