BSEE Safety Alert No. 509
Miscommunication and Trapped Pressure Causes Injury During Valve Maintenance
We continue our series of analyses of Safety Alerts from the BSEE (Bureau of Safety and Environmental Enforcement). In each case we review the incident through the lens of the SEMS (Safety and Environmental Management System) rule. There are 17 elements to that rule.
What Happened
The BSEE report Number 509 (Miscommunication and Trapped Pressure Causes Injury During Valve Maintenance) is available here. Its title is Miscommunication and Trapped Pressure Causes Injury During Valve Maintenance. Here is the background, as described in the BSEE report.
A contract worker was injured and evacuated after a gas release incident on an offshore facility in the Gulf of America. The incident occurred while a contract employee was performing maintenance on an E-body control valve on a six-inch gas line. BSEE’s investigation found that residual pressure estimated at 128 psi inside the six-inch gas line was released during disassembly and replacement of the valve’s trim and seat. The sudden release caused the valve’s bonnet flange, weighing approximately 50 pounds, to be forcefully ejected. The flange struck the worker in the chest and abdomen, knocking the worker backward onto the elevated scaffold platform. The worker was evacuated for treatment and evaluation. Injuries included bruising and abrasions to the left abdomen wall and chest, a laceration behind the left ear, and abrasions to the left knee.
SEMS Analysis
Following are the SEMS management elements. The ones that deserve attention with respect to this incident are highlighted.
General
Safety and Environmental Information
Hazards Analysis
Management of Change
Operating Procedures
Safe Work Practices
Training
Mechanical Integrity (Assurance of Quality and Mechanical Integrity of Critical Equipment)
Pre-startup Review
Emergency Response and Control
Investigation of Incidents
Auditing (Audit of Safety and Environmental Management Program Elements)
Recordkeeping (Records and Documentation) and additional BSEE requirements
Stop Work Authority (SWA)
Ultimate Work Authority (UWA)
Employee Participation Plan (EPP)
Reporting Unsafe Working Conditions
Safe Work Practices
Safe Work Practices is clearly the dominant SEMS failure.
JSA not reviewed or signed
Energy isolation permit not completed
PIC not notified
Scaffold tagged ‘do not use’ was used
No fall protection >6 ft
No operations support for a live-system maintenance task ― no qualified operator assigned to assist
Worker assumed depressurization based on casual comment
Requirement to leave 4 nuts partially engaged was not followed
No verification of isolation
Training
This element is secondary, but the following issues are a concern.
Worker inexperienced (<2 years)
Worker unfamiliar with isolation requirements
Worker unfamiliar with documentation requirements
Worker unfamiliar with restraint-nut requirements
Stop Work Authority (SWA)
The scaffold being tagged out suggests SWA culture was weak.
