GB/T 9168-2025 Determination of distillation range of petroleum products Vacuum distillation method

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Card type: Test method

1. Method number / Full name / English name / Replacement relationship

• Standard number: GB/T 9168—2025
• Chinese full name: Determination of distillation range of petroleum products Vacuum distillation method
• English name: Determination of distillation range of petroleum products—Vacuum distillation method
• Replacement relationship: Replaces GB/T 9168—1997 "Determination of petroleum products by vacuum distillation"
• Publication/Implementation: Published on 2025-10-05, implemented on 2026-05-01
• Custodian: National Technical Committee for Standardization of Petroleum Products and Lubricants (SAC/TC280)
• Drafting organizations: Sinopec Engineering (Group) Co., Ltd. Luoyang Technology R&D Center, Sinopec Research Institute of Petroleum Processing Co., Ltd., PetroChina Dalian Petrochemical Company, Guangdong Huizhou Petroleum Product Quality Supervision and Inspection Center, Sinopec (Luoyang) Technology Co., Ltd.
• Main drafters: Jia Ran, Xie Zongchou, Han Xiwei, Liu Huiqin, Jin Yulin, Bai Zhengwei, Li Yi, Sun Fusong, Li Dan, Ren Chenglong, Zhong Bingwen
• Previous versions: First published in 1988, first revision in 1997, this is the second revision

2. Scope of application and non-applicability

• Applicable to: Under reduced pressure conditions, when the maximum liquid temperature reaches 400 ℃, petroleum products and their fractions that can partially or completely evaporate, biodiesel containing fatty acid methyl esters, and the boiling range of BD100 biodiesel.
• Applicable objects: Petroleum products and their fractions, biodiesel containing fatty acid methyl esters with a distillation range within 274 ℃~400 ℃, and BD100 biodiesel.
• Both manual and automatic determination methods are described in detail.
• Dispute handling: In case of dispute, arbitration testing shall be conducted using the manual determination method at a mutually agreed distillation pressure.
• Not applicable: No explicit non-applicable clauses are listed in the original text.

3. Method principle

Under a precisely controlled specified distillation pressure between 0.13 kPa–6.7 kPa (1 mmHg–50 mmHg), the sample is distilled using a fractionation apparatus of approximately one theoretical plate, yielding the initial boiling point, final boiling point, and a curve relating the volume percent recovered to the equivalent atmospheric temperature.

4. Reagents and materials (purity / preparation)

• 6.1 n-Tetradecane: analytical reagent.
• 6.2 Cetane reference fuel (n-hexadecane): meets the fuel requirements in GB/T 386.
• 6.3 Silicone grease: high-vacuum silicone grease specifically produced for high-vacuum applications.
• 6.4 Silicone oil: can be used long-term above 350 ℃.
• 6.5 Toluene: chemical reagent.
• 6.6 Cyclohexane: chemical reagent.
• Appendix A Reagents and materials for verification:
  • A.4.1 Distilled water: meets grade 3 water in GB/T 6682, freezing point 0 ℃.
  • A.4.2 Tin 50% (mass fraction), lead 32% (mass fraction), cadmium 18% (mass fraction) alloy: melting point 145.0 ℃.
  • A.4.3 Tin: melting point 231.9 ℃.
  • A.4.4 Lead: melting point 327.4 ℃.
• Appendix F For dehydration: fused calcium chloride of particle size 8 mesh~12 mesh.
• Appendix F For defoaming: medium-grade steel wool, secondary-grade steel wool, dry porcelain fragments or crushed aluminum sleeves, Hengar particles, silicone fluid (350 cSt), 33% sodium hydroxide solution, hydrofluoric acid, fine emery grains or porous glass.
• Cleaning solvents: Toluene or cyclohexane are commonly used as cleaning solvents (see 9.12 note).

5. Instruments and equipment

• 5.1 Vacuum distillation apparatus: The vacuum distillation apparatus for both manual and automatic determination methods shall meet the requirements described in Figure 1. An optional vacuum gauge (label 1) may have a cold trap (label 2) inserted before the pressure sensor.
• 5.2 Distillation flask: Specification 500 mL, made of borosilicate glass or quartz, meeting the dimensional requirements of Figure 2 or Figure 3, with a heating mantle, and an insulation jacket on the upper part of the heating mantle. The thermometer well may be replaced by an encapsulated temperature probe, in which case the distillation flask shall have a side neck; the thermometer well may be encapsulated within the distillation flask or installed using a 19/38 ground joint; distillation at temperatures not exceeding 400 ℃ may omit the thermometer well; the position of the thermometer well shall not exceed the centerline of the distillation flask.
• 5.3 Vacuum-jacketed distillation column assembly: Made of borosilicate glass, including the distillation column and connected condenser (Figure 4), with dimensions specified in Table 1. The distillation column is sealed in a fully silvered glass vacuum jacket, with a constant pressure inside the vacuum jacket less than 10⁻⁵ Pa (10⁻⁷ mmHg). A liquid drainage chain is suspended above the drip tip of the condenser, at a position 5 mm below the 10 mL scale mark of the receiver; the volume of the drainage chain shall ensure that the volume below the 200 mL scale of the receiver does not exceed 0.1 mL. A groove may be used instead of the drainage chain.
• Table 1 Vacuum-jacketed column assembly dimensions (key components): B 99±4 mm (overflow point), C 85±3 mm, D (outer diameter) 64.5±2 mm, H (inner diameter) 24.7±1.2 mm, M 230±13 mm, O 140±20 mm, P 18.7±1.1 mm, Q 60°±2°, T 18.7±1.1 mm, U 140±5 mm, X 50±8 mm, Y 30±7 mm (distance to the end of the drip tip); non-key components: A 265±10 mm, E 14/23 or 19/38 tapered standard ground joint, F 35/25 spherical ground joint, G 35±10 mm, I 2~12 mm, J 60±20 mm, K 12±7 mm, L (outer diameter) 8 mm minimum, N (outer diameter) 38±2 mm, R not provided, S not provided, V not provided, W 12±7 mm.
• 5.4 Vapor temperature measurement device: Shall meet the requirements of Appendix A. Measurement accuracy ±0.5 ℃ (0 ℃~400 ℃), response time less than 200 s (determined according to Appendix B). The sensor head is located 3 mm±1 mm below the overflow point. Platinum resistance thermometers or thermocouple thermometers may be used, encapsulated in glass or metal. For platinum resistance, the upper part of the spiral winding is the sensor head; for thermocouples, the upper part of the junction is the sensor head; for metal-sheathed devices, the metal-encapsulated temperature sensor head is 1 mm±1 mm above the bottom.
• 5.5 Receiver: Made of borosilicate glass, dimensions conforming to Figure 9. Manual and automatic equipment shall be able to control the temperature inside the receiver within 32 ℃~78 ℃. The receiver of automatic distillation equipment has a liquid level tracking/recording device, with resolution 0.1 mL and accuracy ±1 mL.
• 5.6 Vacuum gauge: Accuracy of absolute pressure measurement below 1 kPa is 0.01 kPa, and above 1 kPa is 1%. Vacuum gauges based on hot wire, radiation, or conductivity detectors are not recommended. The connecting line length should be as short as possible, with an inner diameter not less than 8 mm.
• 5.7 Pressure regulation system: When the absolute pressure is below 1 kPa, it shall be able to maintain system pressure stability within 0.01 kPa; when the absolute pressure is greater than or equal to 1 kPa, it shall be able to maintain system pressure constant within 1% of the absolute pressure. Follow Appendix E. The connecting line length should be as short as possible, with an inner diameter not less than 8 mm.
• 5.8 Vacuum source: Composed of one or more vacuum pumps and several buffer tanks, maintaining pressure stability within 1% over the full operating pressure range. At 100 kPa pressure, a single-stage pump with a flow rate of 85 L/min~130 L/min is suitable; below 0.5 kPa pressure, a two-stage pump is recommended. Buffer tank capacity at least 5 L.
• 5.9 Cold trap: Installed between the top of the condenser and the vacuum source, with coolant refrigeration ensuring temperature maintained below -40 ℃; liquid nitrogen may be used.
• 5.10 Low-pressure air or carbon dioxide: Used to cool the distillation flask and heater after distillation is completed.
• 5.11 Low-pressure nitrogen source: Releases the system vacuum to atmospheric pressure.
• 5.12 Safety barrier or safety shield: Recommended to use tempered glass, 6 mm thick transparent acrylic, or transparent material of equivalent strength.
• 5.13 Coolant circulation system: Supplies coolant to the receiver and condenser system, with temperature control accuracy ±3 ℃ within the temperature range 30 ℃~80 ℃.

6. Recommended operating conditions

• Distillation pressure range: 0.13 kPa–6.7 kPa (1 mmHg–50 mmHg).
• Most commonly used distillation pressure: 1.3 kPa (10 mmHg); for most heavy oil products with boiling points exceeding 500 ℃, the operating pressure is usually specified as 0.13 kPa (1 mmHg) or 0.26 kPa (2 mmHg).
• Distillation rate: 6 mL/min~8 mL/min (after recovering 10%, it should be controlled within this range).
• Condenser coolant temperature: at least 30 ℃ lower than the lowest vapor temperature observed during the test; for most samples, a suitable coolant temperature is 60 ℃.
• Receiver temperature: 32 ℃~78 ℃.
• Coolant circulation system temperature control: 30 ℃~80 ℃, precision ±3 ℃.
• Vapor temperature measurement precision: ±0.5 ℃ (0 ℃~400 ℃), response time less than 200 s.
• Constant pressure inside the vacuum jacket: less than 10⁻⁵ Pa (10⁻⁷ mmHg).
• Cold trap temperature: below -40 ℃.
• Distillation endpoint: stop distillation when the liquid temperature reaches 400 ℃ or when the vapor reaches its maximum temperature before the distillation endpoint; stop distillation when the maximum vapor temperature is higher than 350 ℃.

7. Sampling and specimen preparation

• 7.1 Sampling shall be carried out in accordance with GB/T 4756, GB/T 27867. In the laboratory, use 4 L~8 L representative samples for a series of tests and analyses; this test requires an aliquot of sample greater than 200 mL.
• 7.2 The mass fraction of water in the sample shall not be greater than 0.03%. If there is obvious water, dehydrate according to F.1 in Appendix F; a sufficient amount of sample must be used for dehydration to ensure that the distillation flask can be provided with 200 mL of test specimen.
• 7.3 Use GB/T 13377 or SH/T 0604, together with GB/T 1885, to determine the sample density at the receiver temperature.
• 7.4 If the collected sample cannot be tested immediately, store it at room temperature or below room temperature. If the sample is collected in a plastic container, transfer the sample to a glass or metal container before storage.
• 7.5 The sample shall be completely liquid before being placed into the distillation flask. If visible crystals are present, heat to an allowable temperature to ensure the crystals dissolve. Depending on sample amount, viscosity, and other factors, stir the sample vigorously for 5 min~10 min to ensure uniform mixing. If visible solids are still present in the sample above 70 ℃, these solid particles are inherent inorganic substances and not a distillable portion; most solids may be removed by filtration or decantation. Some substances, such as visbreaker residue and high-melting-point paraffin wax, still cannot become completely liquid at 70 ℃, but these solid and semi-solid substances are part of the hydrocarbon feed and therefore shall not be removed.
• 9.2 At the receiver temperature, determine the mass equivalent to 200 mL of sample based on the sample density, and weigh it into the distillation flask to the nearest 0.1 g.

8. Analytical procedure

• 8.1 According to Appendix A, check the temperature sensor and the associated signal conditioning and processing device as a whole, at least 1 time(s) every 2 year(s).
• 8.2 According to Appendix E, check the working state of the pressure regulation system, at least 1 time(s) every 2 year(s).
• 8.3 Clean and dry the glass components, and lubricate the distillation apparatus joints with high-vacuum silicone grease; the amount of grease should not be excessive. When using gaskets to seal glass component joints, it is advisable to check whether the gaskets have aged before the test and replace them periodically.
• 8.4 Install the apparatus without the test specimen as described in D.3.2 and perform a leak test.
• 8.5 According to the requirements of Appendix G, use one reagent from 6.1 and 6.2 to check the entire apparatus, and perform a whole-apparatus check 1 time(s) at least every 6 month(s).
• 9.1 Adjust the condenser coolant temperature so that it is at least 30 ℃ lower than the lowest vapor temperature observed during the test. For most samples, the suitable coolant temperature is 60 ℃.
• 9.2 At the receiver temperature, determine the mass equivalent to 200 mL of sample based on the sample density, and weigh it into the distillation flask to the nearest 0.1 g.
• 9.3 Apply an appropriate amount of silicone grease to the spherical joint of the distillation column, or use gaskets to seal the connections of each component. Connect the distillation flask to the lower spherical joint of the distillation column; after placing the distillation flask on the heater, install the top insulation jacket and use spring clips to connect the remaining parts of the apparatus, ensuring that all connections are clamped tightly.
• 9.4 Place a small amount of silicone oil at the bottom of the distillation flask thermometer well, and insert the temperature sensor into the thermometer well. Glass fiber wool may be used at the top of the thermometer well to secure the temperature sensor.
• 9.5 Start the vacuum pump and observe whether the sample in the distillation flask foams. If the test specimen foams, slightly increase the apparatus pressure until the foam subsides. A slow heating method may also be used to help remove dissolved gases. To suppress excessive foaming of the sample, proceed in accordance with F.2.
• 9.6 The vacuum level of the apparatus shall reach the distillation pressure. If the distillation pressure is not reached, or if the apparatus pressure steadily increases when the pump is off, this indicates a serious leak in the apparatus. A nitrogen source may be used to restore the apparatus to atmospheric pressure, and the glass component joints shall be relubricated and resealed. If the distillation pressure still cannot be reached, other components of the apparatus need to be checked for leaks.
• 9.7 After the apparatus vacuum level reaches the distillation pressure, turn on the heater to heat the distillation flask; select a suitable heating rate according to the sample properties and composition to avoid excessive foaming or bumping of the test specimen. When vapor or reflux liquid appears at the neck of the distillation flask, adjust the heating rate to ensure that the distillate distillation rate is within the range of 6 mL/min–8 mL/min. At the beginning of distillation, it is difficult to reach the expected distillation rate, but after recovering 10% of distillate, the distillation rate should be controlled within the range of 6 mL/min–8 mL/min.
• 9.8 When the receiver collects the initial boiling point and the recovered volumes at 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, and the final boiling point, the tester records the corresponding vapor temperature, time, and pressure, and then converts the recorded vapor temperature readings into atmospheric equivalent temperature (AET) according to the formula in Appendix H, to the nearest integer. If an automatic apparatus is used, automatically record the initial boiling point, final boiling point, and each recovered volume percentage and distillation rate corresponding to the vapor temperature; the recorded vapor temperature shall be automatically converted to AET by the instrument software program, and the conversion shall be carried out according to the formula in Appendix H. If it is observed that the liquid temperature reaches 400 ℃ or that the vapor reaches its maximum temperature before the distillation endpoint, record the vapor temperature and total recovered volume fraction, and stop distillation. When confirming the conformity of the test sample with the specification, all test items requiring observation shall be recorded.
• 9.9 When a sudden increase in pressure is observed, along with the appearance of white vapor and a decrease in vapor temperature, this indicates that the distilled substance has decomposed. Distillation should be stopped immediately and the relevant phenomena recorded. If necessary, resample and test again at a lower pressure.
• 9.10 After distillation is completed, lower the distillation flask heater 5 cm~10 cm. Use a gentle stream of air or carbon dioxide to cool the distillation flask and heater. If the apparatus needs to be cooled below 200 ℃ for disassembly and assembly, refill the distillation flask with dry nitrogen. Carbon dioxide may also be used for refilling when the liquid nitrogen cold trap is not in use. If an automatic apparatus is used, the apparatus automatically enters the cooling cycle after distillation ends. When the temperature drops below a safe value (usually 100 ℃), the distillation pressure gradually increases to atmospheric pressure. If the apparatus needs to be cooled below 100 ℃ for disassembly and assembly, dry nitrogen may be used to return the apparatus pressure to atmospheric pressure.
• 9.11 After the cold trap installed before the vacuum source has warmed to room temperature, recover, measure, and record the volume of light fractions collected in the cold trap.
• 9.12 Remove and empty the receiver, or replace it with an empty receiver; at the same time remove the distillation flask and replace it with a distillation flask already charged with cleaning solvent, and perform the cleaning procedure at atmospheric pressure. After cleaning is completed, remove the distillation flask and receiver, and dry the apparatus using gentle air or nitrogen.

9. Qualitative and quantitative determination and calculation formulas

• 10.1 According to the formula in Appendix H, convert the recorded vapor temperature readings into atmospheric equivalent temperature (AET).
• 10.2 Report the atmospheric equivalent temperature corresponding to the volume percentage of recovered liquid in the receiver, rounded to the nearest integer, and also report the sample identification, density (measured in 7.3), volume percentage of liquid recovered in the receiver, volume of liquid in the cold trap before the vacuum source, and any abnormal conditions (such as foaming or splashing).
• Appendix H formulas:
  • H.1: AET = 748.1×A / {[1/(T+273.1)] + 0.3861×A - 0.00051606} - 273.1
  • H.2 (P≥0.266 kPa): A = 5.1432 - 0.9725×log₁₀P / (2579.329 - 95.76×log₁₀P)
  • H.3 (P≥2 mmHg): A = 5.9942 - 0.9725×log₁₀P / (2663.129 - 95.76×log₁₀P)
  • H.4 (P<0.266 kPa): A = 5.8972 - 0.9976×log₁₀P / (2962.909 - 43.00×log₁₀P)
  • H.5 (P<2 mmHg): A = 6.7615 - 0.9876×log₁₀P / (3000.538 - 43.00×log₁₀P)
  • H.6: K = 31.8×(B+273.1) / D
  • H.7: t = -1.4×[K-12]×log₁₀(Pa/Po)
• This equation applies only to samples with a K factor of 12.0±0.2 for Watson. Assume the K factor is 12, ignoring any influence of the K factor, unless the two contradict each other.
• Appendix G Reference compound distillation temperature verification formula:
  • G.1: t₁₆ = [1831.316/(6.14438 - logP)] - 154.53 (P unit kPa)
  • G.2: t₁₆ = [1831.316/(7.01944 - logP')] - 154.53 (P' unit mmHg)
  • G.3: t₁₄ = [1747.452/(6.1471 - logP)] - 168.44 (P unit kPa)
  • G.4: t₁₄ = [1747.452/(7.02216 - logP')] - 168.44 (P' unit mmHg)

10. Precision

• 11.1 Overview: The precision of petroleum product determination was obtained by statistical analysis of interlaboratory study test results from 9 laboratories determining 8 samples, of which 1 laboratories used automatic vacuum distillation analyzers. The precision of determination for biodiesel containing fatty acid methyl esters and BD100 biodiesel was obtained by statistical analysis of test results from 9 laboratories using various automatic or manual instruments to determine 11 samples, including 8 different biodiesels (from soybean, rapeseed oil, fats and yellow grease, etc.), two biodiesel blends (soybean and fats) and mustard oil, with distillation range 274 ℃~400 ℃.
• Note: The estimated degrees of freedom for biodiesel IBP reproducibility is 22, which does not meet the minimum requirement 30; for biodiesel recovered volume 5%~50%, the estimated degrees of freedom for reproducibility is 18, which does not meet the minimum requirement 30; for biodiesel recovered volume 60%~95%, the estimated degrees of freedom for reproducibility is 25, which does not meet the minimum requirement 30. Users should note that actual reproducibility may differ from the estimated values.
• 11.2 Precision of petroleum product determination:
  • 11.2.1 Repeatability r = M{e^exp[a+b ln(1.8S)]}/1.8, where e is the base of natural logarithms, approximately 2.718, a, b and M are determined according to 11.3.3 (Table 3), and S is the temperature change rate [℃(AET)/%].
  • 11.2.2 Reproducibility R = M'{e^exp[a'+b' ln(1.8S)]}/1.8, where e is the base of natural logarithms, approximately 2.718, a', b' and M' are determined according to 11.3.4 (Table 4), and S is the temperature change rate [℃(AET)/%].
• Table 2 Typical values for precision of petroleum product determination (unit: ℃(AET)):
  • IBP: Repeatability r at 0.13 kPa is 17, at 1.3 kPa is 15; Reproducibility R at 0.13 kPa is 56, at 1.3 kPa is 49.
  • FBP: Repeatability r at 0.13 kPa is 3.3, at 1.3 kPa is 7.1; Reproducibility R at 0.13 kPa is 31, at 1.3 kPa is 27.
  • Temperature change rate 0.5~15.0 ℃(AET)/V% corresponds to the repeatability and reproducibility values for each recovered volume percentage (5%~50%, 60%~90%) as shown in Table 2 (the original Table 2 is not fully listed).
• 11.3 Calculation method for precision of petroleum products:
  • 11.3.1 For an example of precision calculation, see Appendix I. The rate of change in degrees Celsius (AET) for each recovered volume point in Table 2 is expressed as ℃(AET)/V%. It may be assumed that between recovered volumes 10%~90%, the rate of change in degrees Celsius at any point is the same as the average of the rates of change in degrees Celsius at the upper and lower points that include it. The recovered volume interval between the upper and lower points shall not be greater than 20%, but when the recovered volume is 5%, the recovered volume interval between the upper and lower points shall not exceed 10%.
  • 11.3.2 To calculate the precision data between 0.13 kPa and 1.3 kPa (1 mmHg and 10 mmHg), coefficients obtained by linear interpolation from the data given in 11.3.3 and 11.3.4 are required.
  • 11.3.3 The calculation coefficients for repeatability r are shown in Table 3.
  • 11.3.4 The calculation coefficients for reproducibility R are shown in Table 4.
• Table 3 Calculation coefficients for repeatability r:
  • 0.13 kPa (1 mmHg): IBP a=2.372, b=0, M=2.9; 5%~50% a=0.439, b=0.241, M=2.9; 60%~95% a=0.439, b=0.241, M=3.0; FBP a=0.718, b=0, M=2.9.
  • 1.3 kPa (10 mmHg): IBP a=2.246, b=0, M=2.8; 5%~50% a=0.240, b=0.350, M=2.8; 60%~95% a=0.240, b=0.350, M=2.9; FBP a=1.521, b=0, M=2.8.
• Table 4 Calculation coefficients for reproducibility R:
  • 0.13 kPa (1 mmHg): IBP a'=3.512, b'=0, M'=3.0; 5%~50% a'=1.338, b'=0.639, M'=3.3; 60%~95% a'=0.815, b'=0.639, M'=3.3; FBP a'=2.931, b'=0, M'=3.0.
  • 1.3 kPa (10 mmHg): IBP a'=3.424, b'=0, M'=2.9; 5%~50% a'=1.415, b'=0.409, M'=3.2; 60%~95% a'=1.190, b'=0.409, M'=3.1; FBP a'=2.815, b'=0, M'=2.9.
• 11.4 Precision of determination for biodiesel containing fatty acid methyl esters and BD100 biodiesel:
  • 11.4.1 Repeatability: The difference between two consecutive duplicate test results obtained by the same operator, in the same laboratory, with the same instrument, under the same conditions shall not exceed the value in Table 5.
  • 11.4.2 Reproducibility: The difference between two single independent test results obtained by different operators, in different laboratories, with different instruments on the same sample shall not exceed the value in Table 5.
• Table 5 Precision of determination for biodiesel containing fatty acid methyl esters and BD100 biodiesel, 1.3 kPa (10 mmHg) (unit: ℃(AET)):
  • IBP: Repeatability r=39, Reproducibility R=89, Range 274~400.
  • 5%–50% recovered volume: Repeatability r=2.1, Reproducibility R=5.55, Range 274–400.
  • 60%–95% recovered volume: Repeatability r=2.1, Reproducibility R=4.64, Range 274–400.
  • FBP: Repeatability r=24, Reproducibility R=68, Range 274~400.

11. Report

• 10.2 Report the atmospheric equivalent temperature corresponding to the volume percentage of recovered liquid in the receiver, rounded to the nearest integer, and also report the sample identification, density (measured in 7.3), volume percentage of liquid recovered in the receiver, volume of liquid in the cold trap before the vacuum source, and any abnormal conditions (such as foaming or spattering).
• 9.8 When confirming the conformity of the test sample with specifications, all test items requiring observation shall be recorded.
• 9.9 If decomposition occurs, distillation shall be stopped immediately and the relevant phenomena recorded.
• F.2.5 The presence of silicone fluid may cause bias, so the use of silicone fluid shall be noted in the report.

12. Normative References

• GB/T 386 Determination of cetane number of diesel fuel
• GB/T 1885 Petroleum measurement tables (including lubricating oil part, crude oil part, product part)
• GB/T 4756 Manual sampling of petroleum liquids
• GB/T 6682 Specifications and test methods for water used in analytical laboratories
• GB/T 13377 Determination of density or relative density of crude petroleum and liquid or solid petroleum products — Capillary-stoppered pyknometer and graduated bicapillary pyknometer methods
• GB/T 27867 Automatic pipeline sampling of petroleum products
• SH/T 0604 Determination of density of crude petroleum and petroleum products (U-shaped oscillation tube method)
• GB/T 1.1—2020 Directives for standardization—Part 1: Rules for the structure and drafting of standardizing documents (cited in the foreword)

13. Source and verification

This page is an AI translation of the available Chinese method card. Human verification is pending. It is not an official translation of the standard. Check the source standard and product certificate before use.

14. Quick-reference questions and answers