When completing a solid and square bolt up on a loose flange, where should you start?

Starting at the gap of the loose flange is the most effective approach when tightening bolts on a loose flange because it ensures that the preload force is distributed evenly around the flange connection. This technique helps to close the gap more efficiently as you work around the flange, leading to better sealing and alignment.

By beginning at the loose gap, you are addressing the area where the joint is weakest or most misaligned, allowing for a more stable and secure connection as you progressively tighten the bolts. This systematic approach promotes uniform clamping force, reducing the risk of creating additional gaps or misalignments elsewhere in the flange.

In contrast, starting at the smallest or largest gap might cause uneven tension distribution, which could lead to improper sealing or structural integrity issues. Working from any random point along the flange could also result in ineffective tightening, as this may not target the areas that need the most attention. Therefore, focusing on the gap of the loose flange is crucial for achieving a proper and reliable fit.