Berkeley Engineering And Research, Inc.
Plures Intelligens Modicum Machinatorem
Telephone: 510-549-3300 
Fax: 510-962-8230 

BEAR Project Receives Award

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BEAR wins Best Paper of the Year

BEAR paper on preventing gasoline can explosions wins Best Paper of the Year

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Alcohol Containers Explode Too!

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Pipeline Explosions and Risk Management

 
 

Any Pipeline Rupture is a failure in risk management. BEAR engineers are on the ASME Piping Code Mechanical Design Committee. We have performed the most recent fracture assessment of the Alaska Pipeline and continually perform tests in our laboratory in Berkeley, California on all types of pipes and pipe materials to assess their strength and structural integrity.

 

 
  Testing Pipe Integrity in the BEAR Lab  
  BEAR engineers have the ability to set up unique tests to assess both normal and unusual operating conditions. The photograph below-left shows a fatigue test machine BEAR engineers built specifically to test refinery piping elbows with thin spots. The video below-right shows a high pressure burst test conducted at BEAR to determine the pressure resistance of large diameter gas pipe with (1) thinning due to corrosion and (2) a longitudinal weld only halfway through the pipe wall thickness.  
 
Pipe
 
 

 

Risk Analysis Process

 
 
Risk modeling typically starts with an event tree analysis that is supported by data collection, inspection and design re-appraisal (right). This allows key operating and damage events to be assessed individually and for their risk. The graph below shows the general risk failure rate of pipelines as a function of time; often referred to as a "bathtub" curve. Failures and problems are high at first as construction defects are eliminated. Then there is a long period with few problems that typically lasts many decades. This is followed by an increase in fialures as the pipeline nears the end of its life.
 
 

 

Inspection Methods Depend on Damage Mechanisms

 
 

Damage Mechanism

Inspection/Detection Methods

  • Weld Fatigue, Incomplete Welding, and Cracking
  • Hydrostatic pressure test
  • Corrosion
  • Pigging, direct inspection, hydrostatic pressure testing
  • Third Party Damage, i.e. backhoe strikes and solid movement especially with older pipes.
  • Hydrostatic pressure testing

Note: only hydrostatic pressure testing can be used to detect and mitigate all common damage mechanisms