CUI Major Incident# 10: DOW chemical Plant

cui incidents Sep 10, 2020

Data and place of incident:

On March 13, 2008, the explosion was occurred at a Dow’s LHC plant, located at Freeport, TX USA.

Summary of the incident:

The carbon steel hydrocarbon of 8 inch, failed. The incident began with the detection of small pinhole leak. When the line was being isolated and de-pressurized, it failed disastrously. This disastrous line rupture fortunately produced such explosive forces which made the line bent in two locations and sealed itself which avoided the major release.

Root cause:

The main cause of pipe leak was corrosion under the insulation.
The piping of carbon steel regeneration line which led to the ethylene plant cracked gas dryer was 30 years old.
Non-corrosive hydrocarbon cracked gas was the material in the line.
The piping alternates three conditions because of the regeneration service. The failure location was where the operating temperature caused continuous or frequent condensations and re-evaporations of atmospheric moistures.

Financial loss to Freedom Industry:

The total loss of the plant was $18.67 million by the incident which included loss of work days of 64 days.

Injury and Fatality:

No injury and fatality was reported in the incident.

Environmental Impact of Incident:

No environmental impact was reported in the incident.

Non-Compliance of Safety Guidelines and Reliability Practices:

The previous inspection conducted in 2004 was performed according to API 570 was not satisfied and did not inspected correctly.
The inspection at the elbow was the most critical point for inspection and a insulation small plug at the elbow was removed for this reason. The insufficient insulation was removed purposely to permit simple external inspection.

Recommendations to Avoid Corrosion:

The particular pipe location is susceptible to corrosion under insulation. The pipeline location should be replaced by thicker wall pipes
Alternative metallurgy should be used to avoid such conditions.
Periodically inspection for corrosion under insulation thoroughly should be conducted.

Links to Photos and videos of incidents:

Sampaio, A.L.M.V. Leite. “More Lesson ReLearned from Corrosion Under Insulation,” 13 Mar. 2018. http://www.penderlo.com/doc/Dow_CUI.pdf.

https://www.csb.gov/assets/1/20/csb%20final%20report.pdf?13966