What pattern should always be used when tightening a flange?

When tightening a flange, the star pattern is the recommended method because it helps ensure that the load is distributed evenly across the flange. This technique involves tightening the bolts in a sequence that resembles a star, starting from one bolt and moving to the opposite one, and then to the next one in the sequence.

This method is critical for maintaining proper alignment and preventing warping of the flange or gasket, which could lead to leaks or failures in the system. By tightening in a star pattern, you help to ensure that the joint is compressed evenly, minimizing stress concentrations on the flange and its components. This pattern reduces the risk of over-tightening any single bolt, promoting a more reliable and consistent sealing force around the entire flange.

In contrast, other patterns, such as diagonal, sequential, or circular, do not provide the same level of even pressure distribution and can lead to uneven tension across the bolts. This can result in issues such as gasket blowout or damage to the flange itself over time. Thus, the star pattern is established as the best practice for flange tightening.