Pressure and Temperature Fluctuations in Underground Storage Tank Pipelines Containing Gasoline

摘要

A common method of detecting a small leak in a pressurized underground storage tank pipeline system containing petroleum is to monitor the pressure in the line. A leak is declared if the pressure drops below a specified threshold pressure. Small changes in the temperature of the product in the line also produce large changes in pressure which can easily exceed those of a small leak. The paper presents theoretical models to predict the pressure changes associated with leaks and product temperature changes in pressurized pipelines. These models have been validated in experiments at retail petroleum facilities and the EPA's UST Test Apparatus. The magnitude of the product temperature changes that can be expected during a pressure test at a retail station is predicted from a heat conduction model. The model includes the effects of product delivery and product dispensing and uses experimentally determined values of thermal diffusivity for the product in the pipeline and for the gravel and soil around the pipeline.