This paper describes the development and use of objective and subjective evaluation criteria for hydrostatic pressure tests of oil pipelines at marine terminal facilities by a California state agency. Many regulatory agencies require a periodic hydrostatic pressure test (hydrotest or static liquid pressure test) to re-validate the integrity of a pipeline. Performance variables for a typical test include: test duration, test pressure, test medium temperature, ambient environment temperature, and volumetric changes. At California State Lands Commission, Marine Facilities Division, an Excel spreadsheet is used to evaluate test results. The spreadsheet is also used by many marine oil terminals and contracted testing companies. The spreadsheet aids the user to: perform pretest checks, record input, quantify numerical output, and plot graphical output. The pretest checks include calculating fill volume and determining significant trapped air. The graphical output provides a visual presentation for the test variables of time, test medium temperature, ambient environment temperature, actual test pressure, theoretical test pressure, and allowable pressure variance. Acceptable pressure range is shown as a plus or minus bandwidth around the theoretical test pressure, and is based upon the thermal expansion sensitivity of the test medium. For those test results that fall partially outside the acceptable pressure range, interpretive criteria are used involving data trends and correlations. The spreadsheet software is the property of the State; however, it is freely distributed to anyone who requests a copy. An acceptable hydrostatic pressure test is achieved by adequate test preparation, quality data collection, and quantitative, and often times, interpretive results evaluation.

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