PSM DEFECTS, LEAD TO REBOILER EXPLOSION

Created on March 6, 2017

When was the last time you were trapped in a deep talk with somebody? No, no, there is not a story about love and yet it’s about our roles in industries. Recently, I have some talks with a new-good-pal during our daily works in office. However, it was the reason why I would share this topic.

On our holistic conversations, the question from him was “Ben, how does the process safety engineer run his/her business exactly?”. After the question was addressed to me, I stuck for a while and remember what I have done already with my team. In this topic discussion, I have some thoughts that I want to share about Process Safety Management (PSM) failure through this SafetyBuzz, where it may include into process safety business in industries and at the same time I hope it answers that question.

Let me come up here with the topic of:

“REBOILER FAILURE DUE TO PSM PROGRAM DEFICIENCIES”

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The William Geismar Olefins Plant produces ethylene and propylene for the petrochemical industries. The plant produces 1.35 billion pounds of ethylene and 80 millions pounds of propylene per year. The incident occurred during non-routine operational activities that introduced heat to a reboiler which was offline, creating an overpressure event while the vessel was isolated from its pressure relief devices.

This incident killed two employees and 167 personnel is reported injuries. We can see that the below information is the brief sequences of the incident occurred.

  1. As per design, the both reboiler (in the picture) are running simultaneously. But in that configuration, the propylene fractionator had to be shut down when the reboiler fault and needed cleaning.
  2. To prevent shut down of the propylene fractionator (because each time reboiler has to be cleaned), in 2001, the new valves (A1, A2, B1, B2) were installed in each reboiler to allow for operation of only one reboiler running at the time. Meanwhile, the another reboiler is on standby, cleaned, and ready for use.
  3. In fact, the new installed valves (A1, A2, B1, B2) have introduced a serious hazard, because the valves have isolated the standby reboiler from its protective pressure relief valve located on top of the fractionator.
  4. June 13, 2013, during a daily morning meeting with operations and maintenance personnel, plant manager noted that the quench water flow through the operating propylene fractionator reboiler (Reboiler A) had dropped gradually over the passed day. An operation Spv informed the group that fouling within Reboiler A could be the problem and need to switch the propylene fractionator reboiler to Reboiler B to fix the quench water flow.
  5. While the operation manager was not available, the operation Spv decided to fix the quench water flow.
  6. Operation Spv opened the quench water valve (Q1) on the offline/ standby reboiler (Reboiler B).
  7. Reboiler B is standby/ offline for 16 months – The operation Spv didn’t know that flammable liquid propane accumulated on the shell side of the standby Reboiler B (due to mistakenly open/ leaking B2 block valve).
  8. When the Spv opened the quench water valve (Q1), hot water begins flowing inside the tube of Reboiler B. Meanwhile, the valves (B1) blocking reboiler from its protective relief valve remains close.
  9. Hot water quickly heated the liquid propane confined inside the reboiler shell, and pressure dangerously increase.
  10. Three minutes later, the Reboiler B fails until rupture due to liquid thermal expansion.

 

Based on incident investigation report, the below summarized conditions lead to this catastrophic incident:

  1. Management of Change (MOC) process failure,
    They perform MOC review to identify how this action affected to the safety of the process. However, they don’t identify that the new valve could isolate the reboiler from pressure relief valve. Furethermore, the MOC is conducted AFTER the process was already operating with a new valves!
  1. Pre-Start Up Safety Review (PSSR) process failure,
    The PSSR reviewers did not response to process safety question. The follwing question is left blank: “PRV’s lined up and block valves sealed open? Pressure release systems in place and operational and traced where appropriate?”
  1. Lack of Process Hazard Analysis (PHA) and Operating Procedure
    Operation supervisor opened the quench water valves (Q1) on the Reboiler B, while its shell-side process valves (B1) remained closed, inititating overpressure event. Prior to manipulating valve Q1, they did not conduct a hazard analysis and did not develop a procedure for the operation activity.

 

Based on conditions above, thus, one of important business of process safety engineer/consultant is to help people to ensure effective Process Safety Management (PSM) Program has been in place and implemented in industries. Safe our life by maintaining proper PSM implementation in our plants!

 

I have some thoughts that I want to share on how to assess whether your PSM implementation is what it should be. Are you sensitive to the possibility of defects in PSM implementation in your plant that might introduce an unacceptable level of risk? I am interested in your experiences and insights. Let’s talk!

You can observe the detail report and video of this incident in www.csb.gov.

http://www.csb.gov/csb-releases-new-safety-video-detailing-investigation-into-2013-fatal-fire-and-explosion-at-the-williams-olefins-plant-in-geismar-la/

Kind Regards and wassalam,
Ir. Beny Desiatwan, SFS
Process Safety Engineer
LebSolution

www.lebsolution.com
http://www.linkedin.com/company/lebsolution-indonesia


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