The test method involves passing a con- trolled flow rate of air through a test chamber that contains a test liquid and a test nm seal, and measuring the concentra- tion of the test liqu
API Normative Standards
Manual of Petroleum Measurement Standards, Chapter
19.3, Part F, “Evaporative Loss Factor for Storage
Tanks Certification Program:’ First Edition, March
Manual of Petroleum Measurement Standards, Chapter
19.3, Part G, “Certijìed Loss Factor Testing Laboratory Registration, ” First Edition, March 1997
ASTM Normative Standards
D323 Test Method f o r Vapor Pressure of Petroleum Products (Reid Method)
E220 Method for Calibration of Thermocouples by Comparison Techniques
E230 Temperature-Electromotive Force (EMF) Tables for Standardized Thermocouples
MFC-3M Measurement of Fluid Flow in Pipes Using
The ACT facility encompasses all components utilized in the Air Concentration Test method, including the test chamber, sensors, data acquisition system, air blower, air inlet and outlet ducts, and storage for the test liquid.
The air concentration test method is utilized to determine evaporative rim-seal loss factors for rim seals on external, covered, and internal floating-roof tanks This method involves directing a controlled airflow through a test chamber containing a test liquid and rim seal, while measuring the concentration of the test liquid vapor in the air streams entering and exiting the chamber.
A covered floating roof is created by placing a fixed roof over an external floating roof on top of the tank shell This design transforms the external floating roof into an internal floating roof while maintaining the characteristics of an external floating-roof system Typically, these floating roofs are engineered in accordance with Appendix C.
‘ASTM International, 100 Bar Harbor Drive, West Conshohocken, Penn- sylvania 19428
2American Society of Mechanical Engineers, 345 East 47th Street, New York New York 10017
Provided by IHS under license with API Licensee=Technip Abu Dabhi/5931917101
2 CHAPTER 1 EVAPORATIVE TIVE Loss MEASUREMENT of the American Petroleum Institute Standard 650, Welded
Steel Tanks for Oil Storage
3.1.4 data acquisition: The process of receiving signals from the sensors, determining the values corresponding to the signals, and recording the results
The deck of a floating roof is essential for providing buoyancy and structural support, covering most of the liquid surface in a bulk liquid storage tank It features an annular space around its perimeter, allowing for vertical movement as the tank is filled or emptied, preventing any binding against the tank shell This space is sealed with a flexible rim seal, and the deck may also include penetrations secured by deck fittings to facilitate various operational functions of the tank.
Deck fittings are essential devices that effectively seal penetrations in the deck of floating roof bulk liquid storage tanks These openings are usually designed to support specific functional or operational features of the tank.
Certain internal floating roofs feature deck seams created by mechanically joining deck sheets or panels, which can lead to deck seam loss In contrast, other internal or external floating roofs utilize metal sheets that are welded together, eliminating the issue of deck seam loss.
The evaporative loss factor is a crucial expression for floating roof devices, used to determine the standing storage evaporative loss rate in bulk liquid storage tanks This factor is adjusted based on specific characteristics of the climatic conditions and the properties of the stored liquid, ensuring accurate calculations of evaporative losses.
The characteristics of the stored liquid are expressed as a vapor pressure function, a vapor molecular weight, and a product factor
An external floating roof is a type of roof that is directly exposed to environmental conditions, as it is situated in a bulk liquid storage tank without a fixed roof This differentiates it from internal floating roofs, which are protected from the elements by a fixed roof External floating roofs are generally designed following the guidelines outlined in Appendix C of the American Petroleum Institute Standard 650, Welded.
Steel Tanks for Oil Storage
An internal floating roof is designed to remain sheltered from environmental conditions, as it is situated within a bulk liquid storage tank that features a fixed roof at the top This type of floating roof is distinct from external floating roofs due to its enclosed design, which helps to minimize evaporation and maintain product quality.
The internal floating roof is designed to be protected from environmental exposure by a fixed roof These roofs are typically constructed following the guidelines outlined in Appendix H of the American Petroleum Institute Standard 650, which pertains to welded steel tanks for oil storage.
A floating roof is a device designed to float on the surface of stored liquids in bulk liquid storage tanks, significantly minimizing evaporation by covering the liquid product surface This system consists of a deck, a rim seal, and various deck fittings, enhancing the efficiency of liquid storage.
An indicator is a device that displays or records signals from a sensor, converting them into useful measurement units For instance, an electronic signal may be received in volts but displayed in pounds Indicators can be integrated into electronic data acquisition systems, which are designed to record data at set intervals, analyze the received information, and electronically store the results.
3.1.13 instrument: A device used in the measurement process to sense, transmit, or record observations
The product factor is a key element that characterizes the evaporative loss properties of a liquid product To calculate the standing storage evaporative loss rate of a bulk liquid storage tank with a floating roof, the product factor, along with the vapor pressure function and vapor molecular weight, is multiplied by the total equipment loss factors.
A rim seal is a flexible device designed to cover the annular space between the tank shell and the edge of the floating roof deck Effective rim seals not only close this gap but also adapt to any irregularities between the floating roof and the tank shell, ensuring proper centering of the floating roof while allowing for its normal movement.
A sensor is a device that detects specific attributes or measurement data during a measurement process, subsequently transmitting this information to an indicator for display or recording.