【国外标准】 Standard Test Method for Total Water in Liquid Butane by Liquefied Gas Sampler and Coulometric Karl Fischer Titration

5.1 High water concentrations can have a detrimental effect on the many uses of liquefied petroleum gas (LPG). Wet butane, propane, and other low molecular weight hydrocarbon products can cause operational issues in customer equipment and downstream processes. Water can cause corrosion problems and create safety hazards during the storage, distribution and use of liquefied petroleum gas (LPG) and pressurized low molecular weight hydrocarbon samples.5.2 While the dryness of propane may be monitored with a “functional” test such as the valve freeze Test Method D2713, this test method provides an analytical method to directly measure water content in LPG and pressurized low molecular weight hydrocarbons and their mixtures.1.1 This test method describes the use of a specialized liquefied gas sampler coupled to a coulometric Karl Fischer (KF) titrator for the determination of water in liquid butane with water concentrations from 1 mg/kg to 100 mg/kg.NOTE 1: Other liquefied petroleum gases described in Specification D1835 including propane, propene (propylene), butylenes and mixtures of these materials and other light hydrocarbons, and dimethyl ether described in Specification D7901, can be analyzed by this method but the precision has not been studied and therefore the stated precision has not been validated for these materials.1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.1.3 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. See Section 10 for specific warning statements.1.4 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.