One worker died due to inhalation
of H2S while trying to take out a safety valve for maintenance. It was later
determined that he removed the flange bolts of the wrong relief valve and he
was working without a permit. His supervisor had pointed to the safety valves
(there were two of them at a height) and told him to remove one. He assumed the
worker knew which valve to open.
November 28, 2017
November 24, 2017
Tank collapse incident
A fixed atmospheric
storage tank was taken out of service for repairs. During re commissioning, the
tank was filled up with water to check for leaks. After the leak check, the
contractor handling the testing process was instructed to drain the tank of water
using the 4” drain valve located at the bottom of the tank. As the contractor was
pressed for time, he decided to open the 24” tank bottom manway also, to speed
up the process of draining. After some time, a loud bang was heard and the tank
collapsed due to vacuum. The venting arrangement in the tank was not sufficient
to prevent vacuum in the tank when the manway was opened.
November 22, 2017
Ammonia storage and business continuity risk
I recently attended an international conference in
the Middle East, about issues with large scale storage of ammonia and new
developments in ammonia production. There was an interesting case where
an operator of a large atmospheric ammonia storage tank located in a port city
for many years was forced by the authorities to decommission the tank
as there was a threat by an adversary to hit the tank with missiles. The
case study pointed out that the company had taken measures to protect
the tank. Though dispersion models
predicted a much smaller exclusion zone in the event of a tank rupture,
the public relations measures and risk communication by the company
could not prevent the court judgement and finally the tank was
decommissioned. A group of scientists had published a report that in the
event of an attack on the ammonia tank, the effect would be similar to
the dropping of 5 atomic bombs. But the results of QRA studies did not match with the
prediction.
The case study has lessons for us in
India. The FACT ammonia tank supreme court judgement many years ago took
a pragmatic view of the matter. But today, public's perception of risk
is only about consequences and does not consider probability of
occurrence! There are a large number of atmospheric ammonia storages in
India where construction of houses by public, near the tanks, have been
permitted by authorities, with the net result that the buffer zone that
was originally present has disappeared. It's a point to ponder!
Industries with large quantities of toxic materials may be the ones that
may be asked to move...
November 18, 2017
November 15, 2017
November 13, 2017
Alarm management
http://www.plantservices.com/articles/2017/automation-zone-alarm-management/
Contribute to the surviving victims of Bhopal by buying my book "Practical Process Safety Management"
Contribute to the surviving victims of Bhopal by buying my book "Practical Process Safety Management"
November 10, 2017
November 6, 2017
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