API PUBL 1625-1978

Radian Corporation, under a previous contract with the American Petroleum Institute, performed data compilation and presentation tasks associated with the EF-14 Task Force survey. The survey was primarily concerned with the temperature of gasoline at retail outlets. The data base has been used in this program for studies in three areas: control of hydrocarbon vapors in the automobile refueling operations, determination of the need for temperature adjustment at the service station, and inventory control for gasoline distribution systems.

In the first year's study, Radian compiled the massive temperature data set collected by oil company marketers and created a computerized data base. The data base includes temperatures at four points: (1) the bulk delivery tank, (2) the underground storage tank, (3) the service station dispenser, and (4) the customer's fuel tank. Additionally, various related data were collected including the total daily volume dispensed, physical characteristics of the site, and meteorological data. The survey was conducted at fifty-six service stations located throughout the contiguous United States during calendar year 1975. The year 1975 was representative of average ambient temperature conditions in the United States. The western half was approximately 1°F cooler than the 30-year mean, and the eastern United States was approximately 1°F warmer. Although all stations did not report all requested data, the data base is extensive enough to support sound statistical studies.

The data are described in further detail in the reference, and initial studies involving the temperature data are discussed. The purpose of this report is to present additional results which relate primarily to gasoline temperature adjustment and control of hydrocarbon vapors in automobile refueling. The specific tasks discussed in this report are as follows:

• Validation of the method used for obtaining average dispensed gasoline temperature from strip chart data,

• Study of the relationships among gasoline temperatures, ambient temperatures, and service station characteristics,

• Study of temperature conditions regarding vapor shrinkage and growth during vehicle refueling,

• Calculation of average ambient temperature and of the average temperature of stored and dispensed gasoline during operating hours of service stations,

• Calculation of national average dispensed gasoline temperature,

• Analysis of the effects of temperature adjustment of gasoline volume,

• Development of mathematical models to predict gasoline temperatures, and

• Study of design parameters and cost of temperature adjustment for service station dispensers.

Each of these tasks is discussed in a section of the report. Each section begins with a statement of objectives and a summary, after which the results are presented in further detail.

Throughout this report, results are presented on the basis of geographical region. The same six regions employed in the first-year study have been used. These regions are shown in Figure 1.0-1. The locations of the test stations are given in Table 1.0-1.