1.1 本规程包括从低压采样点获取“活”或高蒸气压原油、凝析油和/或液态石油产品代表性样本的设备和程序，其中采样点压力不足，无法使用实践中所述的浮动活塞缸（FPC） D3700 . 1.2 本规程适用于样品类型，如UN 3类易燃液体，这些液体可能已使用开放容器收集和运输。使用手动活塞缸代替打开的容器旨在防止挥发性（轻端）成分的损失，这可能会影响后续测试结果。 1.3 本规程适用于在50°C条件下对真实蒸汽压小于300 kPa（标称43 psia）的原油、凝析油和/或液体石油产品进行取样。 本实践适用于通常介于实践之间的样本 D4057 （空气污染指数 MPMS 第8.1章）和 D3700 本规程不适用于归类为UN 2类气体的材料 2. （“……在50℃下的蒸汽压大于300 kPa 或在20°C和101.3 kPa下完全气态。”）。 1.4 本规程允许在取样条件下对自由流动的原油进行取样。 1.5 用户有责任确保采样点的位置，以便获得代表性样本。 1.6 以国际单位制表示的数值应视为标准值。 1.6.1 例外- 括号中给出的值仅供参考。 1.7 本标准并不旨在解决与其使用相关的所有安全问题（如有）。 本标准的用户有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 1.8 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ===意义和用途====== 5.1 这种做法允许收集原油和/或凝析油的代表性样品，其中可能含有痕量挥发性溶解组分，如甲烷、乙烷、丙烷和固定气体，这些气体通常会使用常规大气采样方法丢失。 这些高挥发性组分可导致高于大气压力的蒸汽压力条件。当需要准确测定蒸气压、闪点或其他特性时，以及挥发性成分的损失可能影响试验结果时，建议采用本规程。 5.2 本规程旨在采集原油和/或凝析油样本进行测试，以便将危险货物运输分类为UN 3类易燃液体，但不限于分类测试。对光端损耗敏感的其他试验方法也可采用该取样方法。 5.3 实践 D3700 当真实蒸汽压力大于300时，建议使用浮动活塞气缸 预计50°C下的压力为kPa。

1.1 This practice includes the equipment and procedures for obtaining a representative sample of “live” or high vapor pressure crude oils, condensates, and/or liquid petroleum products from low pressure sample points, where there is insufficient sample point pressure to use a Floating Piston Cylinder (FPC) as described in Practice D3700 . 1.2 This practice is intended for use with sample types, such as UN Class 3 Flammable Liquids, that might have been collected and transported using open containers. The use of a manual piston cylinder in place of open containers is intended to prevent the loss of volatile (light end) components, which can impact subsequent test results. 1.3 This practice is suitable for sampling crude oils, condensates, and/or liquid petroleum products having true vapor pressures less than 300 kPa (43 psia nominal) at 50 °C. This practice applies to samples that will typically fall between Practices D4057 (API MPMS Chapter 8.1) and D3700 . This practice shall not be used for materials classified as UN Class 2 Gases 2 (“…having a vapor pressure greater than 300 kPa at 50 °C or is completely gaseous at 20 °C at 101.3 kPa.”). 1.4 This practice allows for sampling of crude oils that flow freely at the conditions of sampling. 1.5 It is the responsibility of the user to ensure that the sampling point is located so as to obtain a representative sample. 1.6 The values stated in SI units are to be regarded as standard. 1.6.1 Exception— The values given in parentheses are for information only. 1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 This practice allows the collection of a representative sample of crude oil and/or condensate that may contain trace volatile dissolved components such as methane, ethane, propane, and fixed gases that would normally be lost using conventional atmospheric sampling methods. These highly volatile components can result in vapor pressure conditions above atmospheric pressure. This practice is recommended whenever accurate determination of vapor pressure, flash point, or other properties are required and where loss of volatile components can affect the test results. 5.2 This practice is intended for capturing samples of crude oil and/or condensate for testing for the purpose of classification for transportation of dangerous goods as UN Class 3 Flammable Liquids, but is not limited to classification testing. Other test methods with sensitivities to light end loss may also utilize this sampling practice. 5.3 Practice D3700 using a floating piston cylinder is recommended whenever true vapor pressures greater than 300 kPa at 50 °C are anticipated.