Safety Lifecycle – Part 3: Developing Risk Tolerance Criteria

“If we accept there is no such thing as ‘zero risk’ then we should not spin the meaning of words with assertions such as ‘all accidents are preventable.’ – Dr. Rob Long In terms of process safety, one definition of risk is, “[The] combination of the frequency of occurrence of harm [the likelihood] and severity [...]

Check Valves and Risk Assessment: Should You Take Credit?

“Unless you go forward then you are going back.”  - Greg Lake Check valves (CVs) are routinely installed as safeguards against reverse flow.  Just as routinely, check valves are dismissed as safeguards during process hazard analysis.  If check valves are of no value, then there is no point in installing them.  On the other hand, [...]

By | 2017-11-14T21:24:36+00:00 September 28th, 2017|PHA, Process Safety, Risk Assessment, Safety Lifecycle|7 Comments

External Plant Fires: What’s the Likelihood?

“A spark neglected makes a mighty fire.”  Robert Herrick During a process hazard analysis (PHA) and a layer of protection analysis (LOPA), the scenario of an external plant fire frequently arises. From our experience facilitating PHAs and LOPAs, we’ve found that a common cause for this is a pooling of flammable liquid or oil getting [...]

By | 2017-09-07T14:02:34+00:00 September 7th, 2017|Chemicals, Gas, PHA, Process Safety, Risk Assessment|1 Comment

Pressure, How high is too high?

“Safety is not a gadget but a state of mind.”  Eleanor Everet Over-pressure scenarios can be defined as a situation resulting from the internal pressure within piping or vessels exceeding the maximum allowable working pressure (MAWP).  The term “over-pressure” can make those in the process industry cringe. This revulsion is born from associating the term [...]

By | 2017-07-21T19:20:57+00:00 March 7th, 2017|PHA, Process Safety Management|0 Comments

Consider

“There is no greater evil than men’s failure to consult and to consider.”  Sophocles In our office, we write a lot of recommendations.  As a rule, we begin recommendations with the words “consider” or “confirm.” This isn’t because we’re looking for weasel-words. It’s because not every recommendation is the best idea. Some recommendations aren’t even [...]

By | 2017-07-24T17:21:52+00:00 December 6th, 2016|PHA, Process Safety Management, Recommendations|0 Comments