Begin with what touches the fluid.
Define the actual composition
Provide the fluid or sample identity, concentration, contaminants and phase. Include cleaning media and any composition changes between operating stages. A broad description such as “chemical” or “gas sample” is not enough to assess the wetted tube and connections.
Match materials to service
The published range includes stainless steel, copper and fluoropolymer options, depending on family and construction. Availability is not evidence of compatibility with a particular chemical. Review the tube, fittings and any other wetted components at the actual pressure and temperature.
Include the sample-quality requirement
For analytical sampling, tell PMA which constituents must reach the analyser and what contamination or surface-treatment restrictions apply. A tube suitable for transporting a fluid may still be unsuitable for a particular measurement method. Specialist materials or surface finishes require a specific review.
