New Stud Bolts Fail Unexpectedly

Over 20 years ago, a thrifty purchasing agent for a large chemical complex was concerned about the high prices of stud bolts that were coated with a plastic-like finish to inhibit rusting. He learned that cadmium-coated studs and nuts were available at more economical prices. 

Some cadmium-plated bolts and nuts were purchased and installed as a test in the plant. More bolts were purchased and eventually some of the cadmium-plated bolts were installed on the outlet piping flanges of a cracking furnace. The high temperature outlet flanges on the furnace started to weep a bit. An experienced, intelligent pipefitter attempted to snug up a few bolts and the nuts crumbled. (The cause of the failure was later determined to be due to corrosion phenomena called liquid metal embrittlement. ) 

The alert mechanic informed the operations supervisors of the failures. Operations shut down the furnace. Maintenance mechanics replaced the bolts with the properly-specified high-strength stud bolts prior to any serious releases. 

Hurricane Procedures Are Improperly Applied to a Tank Conservation Vent Lid 

Hurricane winds and the accompanying intense long-lasting showers frequently threaten U.S. Gulf Coast Chemical Plants. It is not unusual for an area to prepare for one of these potentially dangerous storm systems every few summers. 

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