API MPMS 8.4-2017 pdf download.Manual of Petroleum Measurement Standards Chapter 8.4 Standard Practice for Sampling and Handling of Fuels for Volatility Measurement.
1. Scope* 1.1 This practice covers procedures and equipment for obtaining, mixing, and handling representative samples of volatile fuels for the purpose oftesting for compliance with the standards set forth for volatility related measurements appli- cable to light fuels. 1.2 The applicable dry vapor pressure equivalent range of this practice is 13 kPa to 110 kPa (2 psia to 16 psia). 1.3 This practice is applicable to the sampling, mixing, and handling of reformulated fuels including those containing oxygenates. This practice is not applicable to crude oil. For the sampling of crude oil, refer to Practice D4057/API MPMS Chapter 8.1, Practice D4177/API MPMS Chapter 8.2, and Practice D8009/API MPMS Chapter 8.5. 1.4 The values stated in SI units are to be regarded as the standard except in some cases where drawings may show inch-pound measurements, which are customary for that equip- ment. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility ofthe user ofthis standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.6 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
188.8.131.52 Discussion—In practice the term bottom sample has a variety of meanings. As a result, it is recommended that the exact sampling location (for example, 15 cm [6 in.] from the bottom) should be specified when using this term. 3.1.2 dead legs, n—sections of pipe that, by design, do not allow for the flow of material through them. 184.108.40.206 Discussion—Dead legs are not suitable for obtaining representative samples. 3.1.3 dry vapor pressure equivalent (DVPE), n—value cal- culated by a defined correlation equation, that is expected to be comparable to the vapor pressure value obtained by Test Method D4953, Procedure A. 3.1.4 flush, v—to fill the volume ofthe line or container with the liquid and discard it. In the case of flushing a bottle, it should be filled at least 80 % full. 3.1.5 relieflines, n—sections of pipe that lead to a pressure/ vacuum relief valve. 220.127.116.11 Discussion—Relief lines are not suitable for obtain- ing representative samples. 3.1.6 rinse, v—to thoroughly wet the interior surfaces ofthe sampling container with the material being sampled and then discard the liquid. Approximately 10 % of the container volume is adequate for this purpose. 3.1.7 stand pipes, n—vertical sections of pipe or tubing extending from the gaging platform to near the bottom oftanks that are equipped with external or internal floating roofs. Stand pipes also may be found on ships and barges. 18.104.22.168 Discussion—Stand pipes which are not slotted or perforated will not yield representative samples. Further infor- mation on proper stand pipe design is given in 6.4.3. 3.1.8 Other sample definitions are given in Practice D4057/ API MPMS Chapter 8.1. 4. Summary of Practice 4.1 It is necessary that the samples be representative of the fuel in question. The basic principle of each sampling proce- dure involves obtaining a sample in such a manner and from such locations in the tank or other container that the sample will be representative of the fuel.
6. General Comments 6.1 Sample Containers: 6.1.1 Sample containers are clear or brown glass bottles, fluorinated high-density polyethylene bottles, or metal cans. The clear glass bottle is advantageous because it is easily examined visually for cleanliness, and also makes visual inspection of the sample for free water or solid impurities possible. The brown glass bottle affords some protection from light. The only seamed cans acceptable are those with the seams soldered on the exterior surface. 6.1.2 Screw caps of plastic or metal shall be used for all glass bottles. The caps for glass and metal containers shall have a seal to provide a vapor-tight closure. Inverted cone polyseals, polytetrafluoroethylene (PTFE)-faced media, or other materials that will not be affected by petroleum products shall be used as seals. Ifused, cork seals shall be ofgood quality, be clean, have an intact sealing surface that is faced with tin or aluminum foil, and be free from holes and loose bits of cork. The fluorinated bottles are supplied with polypropylene screw caps. Regardless of the bottle or can type, the screw cap shall be selected to ensure the sample integrity for the duration ofthe sample retain period.