The only way to be absolutely sure that the specified bolt load is achieved in a bolted assembly is to measure the bolt stretch. The only practical way to do that is with ECHO™ Precision Bolt Load Monitoring.
Every other method is guesswork and guesswork can be dangerous, costly, and could lead to unscheduled shutdowns. Ultrasonic verification instantly provides digitized read-out of the true bolt load.
On critical flanges, control of the bolt preload is essential to the performance of the flange. Bolt Load that is too low will not ensure that suitable gasket stress is maintained. Unchecked, this could affect the seal resulting in leakage. A Bolt Load that is too high will result in damage to the flange, bolt, or gasket, potentially resulting in a leak and subsequent safety concern.