After removing surface oxides, what should be the next step in the preparation process?

In the preparation process for brazing, after removing surface oxides, the next critical step is to round the pipe end with an expander. This action helps ensure a better fit between the parts being joined by creating a smooth and uniform surface. A rounded end can facilitate better contact with the filler material during the brazing process, promoting an optimal flow of the filler into the joint and enhancing the overall strength of the bond formed.

Rounding the pipe end also helps avoid any stress concentrations that could occur due to sharp edges or irregularities, leading to potential weaknesses in the joint once the brazing is complete. Properly preparing the surfaces through the rounding process increases the effectiveness of the subsequent steps, such as the application of flux and filler material.

In contrast, checking clearances, sizing pipes, and applying flux are important steps but are typically performed after ensuring the surfaces are properly shaped and ready for jointing. Each step in the preparation process builds upon the last to ensure a strong, effective, and durable braze joint.