API Publication 310:1997 pdf download

API Publication 310:1997 pdf download.ANALYSIS OF REFINERY SCREENING DATA.
The screening measurement data, used in this study, came from the LDAR program required by South Coast Air Quality Management District (SCAQMD), the local air agency in the Los Angeles California area. SCAQMD has a regulation requiring an LDAR program (Rule 1173 – adopted in 1989) which was implemented in 1991. At that time, refineries began recording their screening data and submitting them to SCAQMD each quarter. There is a general requirement to screen all accessible components (valves, flanges, screwed connections, pumps, compressors, and other components with sealed joints) quarterly. The leak definition adopted by SCAQMD is 1,000 ppmv. Approximately 70 percent of the screening data for 22 quarters, over 11 million values, were compiled for this study. Over one million components are screened each quarter in the seven major Los Angeles refineries included in this study.
Because of the great expense involved in performing this screening effort, the American Petroleum Institute (API) was interested in learning whether a more cost effective approach to LDAR could be developed rather than screening every component each quarter. Past experience shows that in these LDAR programs, approximately 99 percent of the components are already in compliance. If efforts could be redirected to only those components that leak more frequently or at higher rates, greater emission reductions may be achieved at lower costs.
OBJECTIVE
The objective of this program, then, was to provide guidance for conducting LDAR programs in a more cost effective manner. information was obtained to characterize the leak rate distribution among various components, processes and refineries to help determine
(1) the design and operational characteristics that influence emissions and
(2) whether a focused LDAR program could be more cost effective at reducing
emissions than the current method of monitoring all system components.
APPROACH
All availabk screening data, compiled under SCAQMD Rule 1173, were obtained for the ARCO. Chevron. Mobil, Shell2, Texaco, Ultramar, and Unocal2 refineries. The data were processed to standardize the file formats and entered into a Microsoft Access database allowing the following queries to be run:
ACQUISITION
Initially, permission was obtained from the seven refineries to acquire their screening data from SCAQMD. The data requested were for the first quarter of 1992 through the second quarter of 1995. Approximately 50 percent of the requested data were obtained from SCAQMD. The refineries were then requested to provide as much of the missing data as possible. The results of the initial data collection effort are summarized in Table 2-I. Ii was apparent that the data collection and reporting by the refineries and the data storage by the agency improved with time. Therefore, after SCAQMD received the next annual data submittal from the refineries, another request for data was made.