Which factor does NOT contribute to resistance to flow in a piping system?

The factor that does not contribute to resistance to flow in a piping system is ambient temperature. While temperature can affect the viscosity of fluids and, consequently, their flow characteristics, it does not directly create resistance in the physical structure of a piping system.

Resistance to flow is primarily influenced by the internal conditions of the piping, such as the roughness and condition of the internal surfaces, which can create turbulence or friction against the flowing liquid. Additionally, fittings, offsets, and valves introduce changes in direction and flow area, all of which can increase resistance due to added pressure drops. Therefore, while ambient temperature can impact fluid properties, it is not a direct contributor to the resistance created by the piping system itself.