CSB approves changes to gas piping & purging procedures

  Sun 6/30/2013

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"No man or woman should not be able to return to their home at the end of the work day." – Carle Crabb, brother of Ron Crabb – one of six people killed in the blast at the Kleen Energy Systems power plant in Middletown, Conn., in February. CSB approves ban on purging with natural gas: urges OSHA & NFPA to adopt recommendations   "There is a safety crisis in the United States energy industry right now," said Rafael Moure-Eraso, Chairman of the U.S. Chemical Safety Board (CSB), speaking at a hearing of a subcommittee of the U.S House of Representatives Committee on Education and Labor, held in Middletown, Conn. – the site of a deadly blast that killed six workers at a Kleen Energy plant under construction on Feb. 7. "There is a dire need of an overall plan to prevent catastrophic accidents like we had at Kleen Energy," he added. While nothing could detract from the pain of the family, friends and coworkers of those six men killed, it may be some solace that a plan is beginning to come together – one that would outlaw the practice of purging gas lines with natural gas, the cause of the explosion which rocked the quiet Connecticut town on Super Bowl Sunday. Late Monday, the CSB approved urgent safety recommendations to OSHA, NFPA and others by a 4-1 vote. The 18 draft recommendations, which were approved without amendments at a public meeting later in the day, aim to prevent deadly explosions and fires during pipe cleaning and purging operations. This is an example of gas being blown inside, a practice which will now be prohibited according to CSB regulations. The accident at Kleen Energy occurred during the planned cleaning of natural gas piping during the commissioning and startup phase of construction. Natural gas was forced through large piping that was to fuel the plant’s large electricity-generating gas turbines, in an operation called a "natural gas blow."  One of the purge pipes was releasing gas and debris into a courtyard area behind the main power building, which was boxed in by the giant recovery steam generators on each side. The investigators estimate that 480,000 standard cubic feet of natural gas was released from that pipe into the courtyard in the 10 minutes before the explosion. Just over 2 million standard cubic feet of natural gas had been released throughout the morning. CSB officials concluded that "significantly more natural gas was released than was actually needed to remove debris from the piping," noting that the amount of gas is enough to fuel a typical American home every day for more than 25 years. The congested area and the orientation of the vent pipe also likely adversely affected the dispersion of natural gas. According to a recent CSB survey, using natural gas to clean pipes remains the most common single practice in power generation industry, employed by 37% of respondents, mainly due to its low cost when compared to the alternatives. Still, the board said it couldn't identify a scenario when gas is necessary to clean piping. Other substances such as compressed air or nitrogen can be used economically to clean piping, as well as a process called "pigging," where devices are propelled through a pipeline to clean it. In the CSB proposed recommendations, OSHA is urged to pass regulations that would prohibit the use of natural gas for pipe cleaning, the cause of the explosion at Kleen Energy, and would prohibit the venting or purging of fuel gas indoors, the cause of the explosion at the ConAgra Slim Jim plant in Garner, N.C., last June that killed four workers and injured nearly 70. Both explosions resulted from releases of natural gas during the installation and commissioning of new piping that led to gas-fired appliances.  OSHA is also urged to require that companies involve their workers and contractors in developing safe procedures and training for handling fuel gas. With roughly 125 power plants across the country expected to commission natural gas-fired combustion turbines in the next five years, the board's recommendations on how to conduct gas purges to clean the pipes safely before putting the turbines online will have wide-ranging ramifications. John Bresland, CSB board member, told the House committee, "We believe that the 18 urgent recommendations proposed today – together with the two urgent recommendations we issued on February 4 – address all of the principal root causes of these two tragic accidents. If adopted by the recipients, I have no doubt that future accidents will be avoided and lives will be saved as a result." CEC Combustion Safety, Inc. has been regularly retained by some of the largest companies in the world to design natural gas piping systems and oversee their installation and commissioning. Our team includes members of numerous national fuel and combustion-related safety code committees. And our expert staff of professional trainers has educated thousands of people including managers, operators and risk/insurance personnel throughout the world. If you have any questions on gas piping installation, purging or how these latest CSB recommendations affect you, please contact our Manager of Customer Service Bob Ohlsen at [email protected] or call us at 216-749-2992. Check us out online at www.combustionsafety.com or www.purgesafe.com. Sources: "CSB Approves Urgent Recommendations to OSHA, NFPA, Others to Prevent Deadly Explosions and Fires during Pipe Cleaning and Purging Operations," U.S. Chemical Safety Board, http://www.csb.gov/newsroom/detail.aspx?nid=330. "U.S. Agency Approves Ban On Natural Gas Use In Purging Pipelines," Hartford Courant, http://www.courant.com/community/middletown/power-plant-explosion/hc-kleen-recommendations0629-20100628,0,6792956.story?page=1. "US Chem Safety Board Urges Changes Following Conn. Plant Blast," Wall Street Journal, http://online.wsj.com/article/BT-CO-20100628-707099.html.

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