UNITED STATES
DEPARTMENT OF LABOR

Text For Citation: 01 Item/Group: 001 Hazard:

Section 5(a)(1) of the Occupational Safety and Health Act of 1970: The employer did not furnish employment and a place of employment which were free from recognized hazards that were causing or likely to cause death or serious physical harm to employees in that, employees were exposed to struck-by hazards: a) On or about June 25, 2012, Elkhorn Construction, Inc. did not ensure that employees were protected from struck-by hazards while performing purging operations on a 16 inch pipeline. Nitrogen was being introduced into a pig launcher vessel attached to the pipeline at high pressure. The 16 inch trap isolation valve was left in the closed position which led to a fast build-up of nitrogen in the vessel above the maximum allowable working pressure. The vessel ruptured due to over-pressurization. The following deficiencies were found with this process: 1. Procedures for performing purging operations were not followed nor was there a verification or oversight process in place to ensure that all valves in the entire process (from pumping unit to receiver) were in the proper positions prior to initiating the purging process. 2. An effective system was not used to monitor, verify and record the pressure in the pig launcher vessel and the pipeline during purging. 3. Effective communication methods between all affected parties were not established and utilized for the purging process. Abatement Note: Among other methods, feasible and acceptable abatement methods to correct these hazards during purging operations would be to follow ASME B31.8-2010 sections 845 and 850 as well as 49 CFR 192. Other more specific methods include but are not limited to: 1) Modify and improve written operating procedures for pipeline purging, pigging and similar operations to include but not be limited to a detailed list of specific valve opening and closing locations, the sequence of which valves to open and close and the inspection of each location to ensure it is in the proper position. 2) Implement a verification, inspection and oversight process for purging and pigging operations to ensure that all operating procedures are followed properly and valves and other critical components are in the proper positions and at appropriate settings. 3) Train all affected employees and contractors who will be performing purging and pigging operations on new procedures. 4) Establish clear and consistent communication methods for purging and pigging operations to be reviewed and coordinated with all affected parties. 5) Perform process hazard analysis on this system and similar systems and equipment to identify potential failure modes and preventative measures for these.