Feedwater Heater

Old Method: Installation or removal of the standard nuts was a headache! The upside-down location, along with limited working room, created a very difficult scenario to manipulate the large hydraulic wrench. A turntable was required to hold and manipulate the tool into position. Furthermore, a star pattern around the flange at incremental torque values was followed. Raise the tool... lower the tool... move the tool. The work was tedious and grueling. 10-12 hours with three workers was required. The heater had a history of leakage, even after tightening to the required 17,000 ft-lbs.

Superbolt® Solution: (16) 3-3/4" Torquenuts® were used. Superbolt® JL-M (Moly) lubricant was utilized to keep the jackbolt torque to a low 91 ft-lbs. 1/2" impacts on a reduced setting were used first. After three passes around each Torquenut® with the impacts the jackbolts registered 75-85 ft-lbs. Approximately 1-1/2 passes with a calibrated torque wrench finished the job. Total tightening time was approximately 1-1/2 hours. No leakage to date.

An estimated 27-33 man-hour savings was realized on this installation!

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