|
Internal
Corrosion of a Pipe Nipple Accident
Metallurgical failure analysis was requested
following the failure of two high-pressure rupture
discs at a chemical plant resulting in an
atmospheric discharge of chemicals. After
extensive metallurgical
investigation, it was determined that a steel
threaded pipe nipple that attached a pressure gauge
through a thread-o-let to a diluent line had failed.
This pipe nipple failure occurred due to extensive
internal corrosion of the internal pipe surface. The pipe,
whose wall thickness was reduced by threading, was corroded fully through the pipe where
the nipple threads had already reduced the pipe wall
thickness. A polished cross
section of the threading on the end of the pipe
as shown in photograph A.
Photograph A:
Polished section showing reduction of pipe wall thickness where threaded nipple was threaded into a thread-o-let.
Back to top
Back to
Plant Accidents
|
Dr.
R. Craig Jerner, Ph.D., PE specializes in accident
investigation and metallurgical failure analysis,
with over 30 years experience as a metallurgical
consultant and accident investigator. He has
testified as a metallurgical expert in over 250
depositions and more than 70 court appearances. If you or someone you know should need the services of Dr. Jerner and J.E.I. Metallurgical, please visit our web site at the buttons below, or e-mail Dr. Jerner --- 