At what minimum size must a syphon be made of non-ferrous material?

The minimum size at which a siphon must be constructed using non-ferrous materials is 1/4 inch. This requirement is based on the need to prevent corrosion and ensure the longevity of the piping system, especially in applications where fluids may be aggressive or corrosive.

When the diameter of the siphon is 1/4 inch or smaller, the use of non-ferrous materials helps mitigate the risks typically associated with ferrous materials, which are prone to rust and deterioration over time. Non-ferrous materials, such as copper, brass, and certain plastics, provide better resistance to corrosion, thus ensuring reliable performance in piping applications.

For any siphon larger than 1/4 inch, ferrous materials may be suitable, but it is the smaller siphon sizes that specifically require the use of non-ferrous materials to maintain system integrity and safety. Thus, 1/4 inch is established as the threshold where the benefits of non-ferrous materials become essential for effective functioning.