5.1 The moisture content of LPG can be critical to the use, transportation, or processing of LPG products, especially at cold ambient temperatures and during pressure throttling, when icing or hydrate formation, or both, are most likely to occur. In order to prevent ice or hydrate formation, or both, the water content has to be low enough to prevent the formation of free water in storage tanks and/or regulators over the entire range of operating conditions (temperatures, pressures, and compositions) encountered during normal service. For example, propane and propane-propene mixtures require moisture levels below the equilibrium saturation level of water at operating temperature and pressure for these hydrocarbons to meet specifications such as Specification D1835.5.2 The presence of free water in a propane system can lead to ice or hydrate accumulation, the blockage of vapor or liquid fuel lines, and disrupt the operation of pumps, meters, filters, valves, regulators, safety shut-off valves, and other equipment.5.3 This test method allows continuous monitoring of process flow streams and could be applied to monitoring of product dryness during transportation operations if it is known that methanol has not been added.1.1 This test method covers the quantitative determination of water in liquefied petroleum gases (LPG) from 1 mg/kg to 250 mg/kg using an online electronic moisture analyzer, also known as an electronic hygrometer or dew point analyzer, in the absence of methanol or other anti-freeze agent.1.1.1 These analyzers commonly use sensing cells based on aluminum oxide, Al2O3, silicone, phosphorus pentoxide, P2O5, piezoelectric-type cells, or laser-based technologies to measure the dew point temperature of LPG.1.1.2 Knowledge of the hydrocarbon composition of the LPG is required to calculate the water content on a mass basis from the dew point temperature of an LPG sample.1.1.3 The LPG shall be free of alcohol (sometimes added as an anti-freeze agent) as it can interfere with the electronic moisture analyzer. Thus the method will be most useful in a process facility where it is known that no methanol has been added to the LPG product.1.2 The values stated in SI units are to be regarded as standard.1.2.1 There is an exception in Appendix X1, where the unit “mbar” is used in data provided by an external source, and parts per million by weight (ppm by weight) is widely used in industry.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.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.

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5.1 Residue in LPG is a contaminant that can lead to operational problems in some end use applications. Engines, micro-turbines, fuel cells and other equipment may be sensitive to residue levels as low as 10 mg/kg.5.2 Contamination of LPG can occur during production, transport, delivery, storage and use. A qualitative indication of the contaminants can help track down the source of the contamination from manufacture, through the distribution system, and to the end user.5.3 This test method is designed to provide a lower detection limit, wider dynamic range, and better accuracy than gravimetric methods like Test Method D2158.5.4 This test method can be performed with little or no discharge of LPG vapors, compared to Test Method D2158 which requires evaporation of 100 mL of sample per test.5.5 Sampling for residue in LPG using sorbent tubes can be performed in the field, and the sorbent tubes sent to a laboratory for analysis. This saves significant costs in shipping (weight of tube is approximately 10 grams), and is much safer and easier than transporting LPG cylinders.5.6 This test method determines total residues from C6 to C40, compared to a thermal gravimetric residue method such as Test Method D2158 which heat the residue to 38°C, resulting in a lower recovery due to loss of lighter residue components.5.7 If there is a need to decrease the detection limit of residue or individual compounds of interest below 10 µg/g, the procedures in this test method can be modified to achieve 50 times enhanced detection limit, or 0.2 µg/g.1.1 This test method covers the determination of residue in LPG by automated thermal desorption/gas chromatography (ATD/GC) using flame ionization detection (FID).1.2 The quantitation of residue covers a component boiling point range from 69°C to 522°C, equivalent to the boiling points of C6 through C40 n-paraffins.1.2.1 The boiling range covers possible LPG contaminants such as gasoline, diesel fuel, phthalates and compressor oil. Qualitative information on the nature of the residue can be obtained from this test method.1.2.2 Materials insoluble in LPG and components which do not elute from the gas chromatograph or which have no response in a flame ionization detector are not determined.1.2.3 The reporting limit (or limit of quantitation) for total residue is 6.7 µg/g.1.2.4 The dynamic range of residue quantitation is 6.7 to 3300 µg/g.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 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.

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5.1 LPG samples can change composition during storage and use from preferential vaporization of lighter (lower molecular weight) hydrocarbon components, dissolved inert gases (N2, Ar, He, and so forth) and other dissolved gases/liquids (NH3, CO2, H2S, H2O, etc.). Careful selection of cylinder type, cylinder volume, and use of inert gas for pressurizing cylinders is required to ensure that composition changes are small enough to maintain the integrity of LPG when used as a QC reference material for various LPG test methods.5.2 Monitoring of ongoing precision and bias on QC materials using control chart techniques in accordance with Practice D6299 can be used to establish the need for calibration or maintenance.1.1 This practice covers information for the storage and use of LPG samples in standard cylinders of the type used in sampling method, Practice D1265 and floating piston cylinders used in sampling method, Practice D3700.1.2 This practice is especially applicable when the LPG sample is used as a quality control (QC) reference material for LPG test methods, such as gas chromatography (GC) analysis (Test Method D2163) or vapor pressure (Test Method D6897) that use only a few mL per test, since relatively small portable Department of Transportation (DOT) cylinders (for example, 20 lb common barbecue cylinders, or common Mower/Forklift cylinders) can be used.1.2.1 Modification of the pressure relief (QCC1) valve on single access port cylinders may prohibit the collection or transport of cylinders outside of permitted facilities such as refineries, gas plants or pipeline stations. No modification is generally required for multi-port mower/forklift cylinders that have a separate access port for pressure relief and additional access ports for filling, liquid/vapor withdrawal or liquid level indication. Consult the Authority having Jurisdiction for detailed regional regulatory requirements for transport of LPG in pressurized cylinders.1.3 This practice can be applied to other test methods. However, test methods that require a large amount of sample per test (for example, manual vapor pressure Test Method D1267) will require QC volumes in excess of 1000 L if stored in standard DOT cylinders or American Society of Mechanical Engineers (ASME) vessels.1.3.1 Test methods for trace materials that may be sensitive to vessel surfaces (for example H2O, H2S/sulfur, or trace residues) could preferably use aluminum, stainless steel or internally coated vessels to minimize surface absorption/reaction or larger vessels to minimize surface/volume ratio.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.

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5.1 The total fluorine, chlorine, and sulfur contained in LPG, similar low molecular weight hydrocarbons, and DME can be harmful to many catalytic chemical processes, lead to corrosion, and contribute to pollutant emissions. While LPG specifications limit sulfur, some specifications also contain precautionary statements about fluorine. Chlorine has been known to contaminate LPG with detrimental consequences. This test method can be used to determine total fluorine (as fluoride), chlorine (as chloride), and sulfur (as sulfate ion) in process streams, intermediate and finished LPG products, similar low molecular weight hydrocarbons, and DME (1.1).1.1 This test method covers the individual determination of total fluorine, chlorine, and sulfur in liquid petroleum gas (LPG), low molecular weight hydrocarbons, their mixtures, and dimethyl ether (DME) in the range of 1 mg/kg to 300 mg/kg fluorine and sulfur and 5 mg/kg to 300 mg/kg for chlorine. This test method is applicable to products described in Specifications D1835 and D7901 and it can be applicable to process streams with similar properties to LPG and other materials such as butylene, propylene, and olefins.1.2 This test method can also be applied to the measurement of the bromine and iodine in samples covered by the scope of this test method, but the precision and bias statement of this test method is not applicable to these halides.1.3 This test method can be applied to sample concentrations outside the scope of this test method through adjustments of sample injection volume or number of injections combusted (or both), adjustment of injection volume to the ion chromatograph, and adjustment of the final dilution volume of the absorbing solution prior to injection to the ion chromatograph. The precision and scope of this test method is not applicable to samples that are outside the scope of the method.1.4 The values stated in SI units are to be regarded as standard.1.4.1 Exception—Values given in parentheses are for information only.1.5 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. See Section 9.1.6 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.

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5.1 Information on the vapor pressures of liquefied petroleum gas is pertinent to selection of properly designed storage vessels, shipping containers, and customer utilization equipment to ensure safe handling of these products.5.2 Determination of the vapor pressure of liquefied petroleum gas is important for safety reasons to ensure that the maximum operating design pressures of storage, handling, and fuel systems will not be exceeded under normal operating temperature conditions.5.3 For liquefied petroleum gases, vapor pressure can be considered a semi-quantitative measure of the amount of the most volatile material present in the product.5.4 This test method uses a small sample volume and excludes any manual handling of a measuring chamber under high pressure.1.1 This test method covers the use of automatic vapor pressure instruments to determine the vapor pressure of liquefied petroleum gas products at a temperature of 37.8 °C, vapor to liquid ratio of 0.5:1, and pressures from 200 kPa to 1550 kPa on a sample volume of 3.33 mL.1.2 This test method is applicable to the determination of vapor pressures of liquefied petroleum gas products at temperatures from 37.8 °C to 70 °C, vapor to liquid ratios of 0.1:1 to 4:1, and pressures up to 3500 kPa; however, the precision of the test method (see Section 15) has only been determined for a vapor to liquid ratio of 0.5:1, at a temperature of 37.8 °C, and a pressure range from 300 kPa to 1500 kPa.NOTE 1: This test method is not intended to determine the true vapor pressure of LPG samples, but rather determine and report the vapor pressure of LPG at the 37.8 °C temperature and 0.5:1 vapor to liquid ratio as the Test Method D1267 method.NOTE 2: This test method is not a true vapor pressure method and will not measure the full contribution from any dissolved gases such as nitrogen or helium if they are present. The contribution of light gases to the measured vapor pressure is highly dependent on the test temperature, type of gas, and V/L ratio of the test.1.3 The values stated in SI units are to be regarded as standard.1.3.1 Exception—Non-SI units are included in parentheses for information only.1.4 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. For specific warning statements, see Appendix X2.

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5.1 This practice allows the collection of a representative sample of LPG that may contain trace volatile dissolved components such as methane, ethane, and nitrogen. Sampling by Practice D1265 can result in a small, but predictable, loss of these lighter components. Practice D1265 is suitable for collecting samples for routine specification testing, as the small loss of light components is not significant under Specification D1835 specification requirements. Practice D3700 is recommended whenever highly accurate determination of light components is required. For example, compositions determined on samples collected according to Practice D3700 may be used to establish the product value of NGL mixtures (see Appendix X1).1.1 This practice covers the equipment and procedures for obtaining a representative sample of liquefied petroleum gas (LPG), such as specified in ASTM Specification D1835, GPA 2140, and comparable international standards. It may also be used for other natural gas liquid (NGL) products that are normally single phase (for example, NGL mix, field butane, and so forth), defined in other industry specifications or contractual agreements, and for volatile (higher vapor pressure) crude oils.NOTE 1: Some floating piston cylinders have such tight piston seals that the vapor pressure of some high vapor pressure crude oils may not be sufficient to allow sampling without a handle to move the piston. An alternative sampling practice for UN Class 3 liquids (under 300 kPa at 52 °C) is Practice D8009, which utilizes a Manual Piston Cylinder (MPC) sampler.1.2 This practice is not intended for non-specification products that contain significant quantities of undissolved gases (N2, 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 standard.1.4.1 Exception—The values given in parentheses are for information only.1.5 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.1.6 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.

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