What must be water flushable after soldering?

After soldering, it's crucial to water flush the flux used in the process. Flux is a chemical cleaning agent that facilitates the soldering of metal by removing oxidation and preventing further oxidation during heating. While it plays an essential role in ensuring a strong bond between the pipes and fittings, it can also be corrosive if left unremoved.

Flushing with water helps eliminate any residual flux that could lead to corrosion over time or negatively affect the water quality if the system is put back into service without the flush. Properly removing the flux ensures that the integrity of the system is maintained.

Although solder and joints are integral parts of the process, neither requires flushing; they typically form a durable bond during soldering. The pipe itself does not necessitate flushing, as it is the flux that poses a risk if not cleaned. Therefore, ensuring that flux is adequately flushed contributes to the overall longevity and safety of the plumbing installation.