Printable version

Country: ---

Location: ---

Incident Date: 15 May 2017   Time: ---

Type of Activity: ---

Cause: Pressure release

Function: ---

An analyzer engineer was fatality injured when the engineer removed the cover on an explosion-proof enclosure as part of a routine task. The threaded cover, weighing ~12 lbs. and measuring 14 inches in diameter, was forcefully propelled from the enclosure as the engineer unscrewed it, inflicting a fatal head injury. The force was caused by pressure inside the enclosure from leaking sample gas or instrument air components. The enclosure was not equipped with an external indicator to determine the pressure inside the enclosure and had no means to relieve internal pressure.

• Recognize the potential hazard of trapped pressure in explosion-proof electrical enclosures from all sources of energy entering the enclosure
• Identify explosion proof enclosures which are susceptible to trapped pressure scenarios and do not have pressure indication or pressure relief protection
• Work with equipment manufacturers to develop a mitigation plan that addresses the trapped pressure situation while still maintaining the electrical certification of the identified enclosures

Figure 1: Re-enactment of cover removal

Figure 2: Example of Explosion-Proof Enclosure

Safety Alert number: 288
IOGP Safety Alerts http://safetyzone.iogp.org/

Disclaimer

Whilst every effort has been made to ensure the accuracy of the information contained in this publication, neither the IOGP nor any of its members past present or future warrants its accuracy or will, regardless of its or their negligence, assume liability for any foreseeable or unforeseeable use made thereof, which liability is hereby excluded. Consequently, such use is at the recipient's own risk on the basis that any use by the recipient constitutes agreement to the terms of this disclaimer. The recipient is obliged to inform any subsequent recipient of such terms.
This document may provide guidance supplemental to the requirements of local legislation. Nothing herein, however, is intended to replace, amend, supersede or otherwise depart from such requirements. In the event of any conflict or contradiction between the provisions of this document and local legislation, applicable laws shall prevail.