Topic: Risk Assessment

Resources to assist the practicing pipeline risk assessor in obtaining complete and accurate risk estimates.

Pipeline Risk Assessment

Risk assessment on any facility is most efficiently done by first dividing the facility into components with unchanging risk characteristics. For a cross-country pipeline, this involves collecting data on all portions of the pipeline and its surroundings and then using this data to ‘dynamically segment’ the pipeline into segments of varying length. Risk algorithms are […]

The Test of Time Estimation of Exposure

In the absence of more compelling evidence, an appropriate starting point for the exposure estimation may be the fact that a component or collection of components has not failed after x years in service. This involves the notion of having ‘withstood the test of time’. A component having survived a threat, especially for many years, […]

Damage vs failure: a risk assessment needs to know the difference

To measure resistance in a way most useful to a risk assessment, we must estimate the possible presence of weaknesses, the rate of emergence of future weaknesses, and the role of each weakness in strength reduction. By W. Kent Muhlbauer, WKM Consulting, Austin, TX, USA Since several of our recent columns have dealt with management-of-risk […]

Measuring Failure Potential—What is Attacking? 

How Effective are Defenses?  Can it Survive? In several previous columns, we have noted the need for a very specific approach to measuring failure probability (PoF).  Three factors must be independently measured/estimated in order to fully understand PoF.  Let’s explore those factors a bit deeper here. Regardless of the definition of ‘failure’ being used, failure […]

The PHMSA has recently criticised how Integrity Management Plan (IMP) risk assessments (RAs) for pipelines are being conducted. Do you also see problems?

There is a wide range of practice among pipeline operators right now. Some RA is admittedly in need of improvement, not yet meeting the intent of the IMP regulation. However, I believe that is not due to lack of good intention, but rather incomplete understanding of risk. Risk is a relatively new concept, and is […]

Consequence of Failure Estimations

Resources to assist in understanding and assessing potential hazard zones and associated damages from pipeline failures: PHMSA leak study (pdf file) PHMSA valve study PIR natural gas (pdf file) PIR other products  Potential Impact Radius Final Report June 2005 (pdf file) Study of pipelines that ruptured at stress below 30pct SMYS PPIM 2013 (pdf file) […]

Exposure Estimations

Resources to help identify and estimate the frequencies and aggressiveness of everything that might be ‘attacking’ the pipeline. US natural hazards database Waters  SCC (pdf file) Mechanical damage report (pdf file) NTSB pipeline recommendations PHMSA advisory bulletins Corrosion (pdf file) US Soils database Fatigue estimation software  Publications Template enabled Excel spreadsheet