Valves are a fundamental part of most hydraulic systems. When properly selected, they can provide many years of trouble-free operation controlling flow or pressure, controlling transients, handling trapped air problems, preventing backflow, avoiding cavitation, noise and vibrations and many other tasks. However, all too often, valves create operational problems.

Valves

Expert Witness

Dr. J. Paul Tullis has served as an expert witness for a number of cases involving valves; including the following:


  • Check valve failure at a Chevron oil refinery. Provided forensic engineering services to determine the cause of thefailure of the check valve. Dr. Tullis prepared expert testimony, written reports, affidavits, two depositions and prepared for trial. The case wassettled the day before it was scheduled for trial.

  • Pipeline failure in South Dakota due to improper valve operation. Provided forensic engineering services to determine the cause of the pipe failures. Prepared several expert reports, affidavits and gave two depositions. Case settled in court. Dr. Tullis spent 6 weeks in court evaluating testimony of opposing experts and testifying for the defense.

  • Failure of a 78 inch diameter concrete pipe for Stockton CA, East Water District. Provided forensic engineering services to determine if the cause of the failure was due to the operation of the air release valves, rapid filling of the pipeline or defective pipe construction. The case was settled out of court.

  • Failure of a large diameter pipeline in Puerto Rico. Provided forensic engineering services to determine the role of operation of the main control valves as a contributing factor in the causing the failure.

  • Asbestos valve packings and health problems. Provided forensic engineering services to determine if valve packings containing asbestos could generate airborne fibers.