ASTM D3700-07

This practice allows the collection of a representative sample of LPG that may contain trace volatile components such as methane, nitrogen, and ethane. Sampling by Practice D 1265 may result in a small, but predictable loss of these lighter components. Practice D 1265 is suitable for collecting samples for routine specification testing, as the small loss of light components is not significant under Specification D 1835 specification requirements. Practice D 3700 is recommended whenever highly accurate determination of light components is required. For example, composition determined on samples collected according to Practice D 3700 may be used to establish product value of NGL mixtures (see Appendix X1).

1.1 This practice covers the equipment and procedures for obtaining a representative sample of specification liquefied petroleum gas (LPG), such as specified in Specification D 1835, GPA 2140, and comparable international standards. It may also be used for other natural gas liquid (NGL) products that are normally single phase (NGL mix, field butane, and so forth), defined in other industry specifications or contractual agreements.

1.2 This practice is not intended for non-specification products that contain significant quantities of undissolved gases (N 2, CO2), free water or other separated phases, such as raw or unprocessed gas/liquids mixtures and related materials. The same equipment can be used for these purposes, but additional precautions are generally needed to obtain representative samples of multi-phase products (see Appendix X1).

1.3 This practice includes recommendations for the location of a sample point in a line or vessel. It is the responsibility of the user to ensure that the sampling point is located so as to obtain a representative sample.

1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

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 and health practices, and determine the applicability of regulatory limitations prior to use.