A Case Study of an Ethylene Oxide Explosion in a Sterilization Facility

The authors present the lessons learned from this incident through their direct involvement with the incident investigation as well as a review of previous, similar incidents investigated by the United States Environmental Protection Agency (EPA). The root cause and contributory factors for this explosion are discussed and recommendations provided on how similar incidents might be avoided in the future. One of the authors serves on the NFPA committee responsible for publishing the standard on safe storage, handling and use of ethylene oxide, and the paper concludes with an regulatory and industry perspective on alternative designs and equipment that could have prevented the exp.

via : CHEMICAL ENGINEERING TRANSACTIONS , Exponent, Failure Analysis Associates, 5401 McConnell Ave. Los Angeles, CA 90066 USA

Elevator chain wheel shaft break analysis

chain wheel shaft is made of normalized steel C45 without heat treatment of the surface. Due to dimensional nonconformity of composing elements of wedge assembly and due to soft shaft surface, at local indenting of the edge of the gear-wheel hub keyway, a small mechanical surface damage occurred on the shaft that resulted in a crack initiation. The outcome of its slow growth, induced by rotation and rather low dynamic tensile-compressive stresses is a final break of the shaft caused by material fatigue.

via : ScienceDirect.com – Case Studies in Engineering Failure Analysis – Elevator chain wheel shaft break analysis.