The sequence in which fasteners are tightened on a sixteen-bolt flanged connection is critical for achieving a uniform and leak-free seal. Instead of tightening bolts in a circular fashion, a specific order, often a star or cross pattern, is employed. This method distributes clamping force evenly across the flange face, preventing distortion and ensuring consistent gasket compression. For example, on a sixteen-bolt flange, a typical sequence might involve tightening bolts in opposing pairs, gradually increasing torque with each pass until the final specified value is reached.
Adherence to a prescribed tightening order offers several benefits. It minimizes the risk of flange warpage, reduces stress concentrations around individual bolts, and ensures the gasket material is compressed uniformly, maximizing its sealing effectiveness. Historically, incorrect tightening procedures have been a major cause of leaks in pipelines and machinery. Consequently, standardized procedures and tooling have been developed to promote proper installation and maintenance of flanged connections, contributing to improved safety and operational efficiency.
