What provides flexibility in terms of tube routing in a pipe fitting application?

The correct answer is that spiral lay bundles provide flexibility in terms of tube routing in a pipe fitting application. Spiral lay bundles are designed with a configuration that allows tubes to be routed in various directions while maintaining the integrity of the system. This configuration enables easier installation and adjustments in confined spaces or areas where rigid layouts are impractical.

By utilizing a spiral design, these bundles can accommodate bends and turns, minimizing stress on the tubes and ensuring fluid flow remains unobstructed. The flexibility offered by spiral lay bundles is particularly beneficial in complex systems where adapting to existing structures or future modifications may be necessary.

Other choices might offer certain advantages in specific contexts but do not match the level of flexibility provided by spiral lay bundles. For instance, straight lay bundles tend to be more rigid and limited in terms of routing options, while changeable fittings focus on adaptability at connection points rather than overall tube routing. Manual adjustments can provide some level of modification but generally require more effort and may not achieve the same streamlined results that spiral lay bundles can offer.