SH/T 0569-1993 Determination of stability of water-in-oil emulsions (low temperature to room temperature cycling method)

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Card type: Test method

1. Method number / full name / English name / replacement relationship

• Method number: SH/T 0569-93 (confirmed in 2004)
• Chinese full name: Determination of stability of water-in-oil emulsions (low temperature to room temperature cycling method)
• English name: not provided in the available source
• Replacement relationship: not provided in the available source
• Reference adoption: ASTM D3709-89 "Determination of stability of water-in-oil emulsions under low temperature to room temperature cycling conditions"
• Approval/implementation: approved by China Petrochemical Corporation 1993-08-19, implemented 1994-05-01

2. Scope of application and non-applicability

• Applicable to water-in-oil emulsions.
• Specifies a method for determining the stability of water-in-oil emulsions under low temperature to room temperature cycling conditions.
• Not applicable: not provided in the available source.

3. Method principle

Take 100 mL of sample and cycle through nine processes under specified conditions. After the entire process is completed, determine the oil separation amount [%(V/V)], water separation amount [%(V/V)], and the water content of the upper and lower layers at the specified locations [%(m/m)].

4. Reagents and materials (purity / preparation)

not provided in the available source.

5. Apparatus and equipment

• 5.1 Cold box: capable of maintaining a constant temperature at −18℃±1.5℃.
• 5.2 Graduated cylinder: 100 mL, with graduations of 1 mL, with a ground-glass stopper. The stopper should have a vent groove to avoid vacuum or pressure increase during the test.
• 5.3 Pipette: 10 mL.
• 5.4 Microsyringe: 0.5 or 1 μL.
• 5.5 Narrow-mouth glass bottle: about 30 mL.
• 5.6 Rubber bulb.

6. Recommended operating conditions

• Cold box temperature: −18℃±1.5℃.
• Room temperature: 21℃±3℃.
• Cycling schedule (nine cycles in total):
  • 7.2 Cold box 16 h → room temperature 8 h.
  • 7.3 Repeat the three-cycle process according to 7.2.
  • 7.4 Fifth cycle: cold box 64 h → room temperature 8 h.
  • 7.5 Repeat the three-cycle process again according to 7.2.
  • 7.6 Ninth cycle: cold box 16 h → room temperature 3 h, then observe.
• Usually the minimum service temperature of the emulsion is limited to −18℃ (see Section 4).

7. Sampling and sample preparation

• Before testing, place the sample in a container of 1 L or 0.5 L, and shake vigorously by hand or mix mechanically for 3—5 min to ensure the sample is uniform.
• Note: Water-in-oil emulsions are two-phase systems, unlike completely homogeneous systems, and therefore are difficult to mix in a large container and to withdraw a representative sample. The best way to obtain a uniform sample is continuous, vigorous mechanical stirring. However, for unstable emulsions that have been stored for more than half a year, this sampling method also cannot obtain a representative sample.

8. Analysis procedure

• 7.1 Use a graduated cylinder to take 100 mL of uniform sample, and cover it.
• 7.2 Place the graduated cylinder in a cold box maintained at −18℃±1.5℃ for 16 h, then remove the graduated cylinder from the cold box and leave it at room temperature (21℃±3℃) for 8 h.
• 7.3 Repeat the three-cycle process as described in clause 7.2.
• 7.4 For the fifth cycle, place the graduated cylinder in the cold box for 64 h, remove it and leave it at room temperature for 8 h.
• 7.5 Repeat the three-cycle process again as described in clause 7.2.
• 7.6 For the ninth cycle, place the graduated cylinder in the cold box for 16 h, remove it and leave it at room temperature for 3 h, then observe.
• 7.7 Observation and recording:
  • 7.7.1 Oil separation amount [%(V/V)].
  • 7.7.2 Water separation amount [%(V/V)].
• 7.8 Using a 10 mL pipette, take samples according to the following steps:
  • 7.8.1 Place the pipette tip accurately at the 80 mL mark of the graduated cylinder, slowly draw 10 mL of sample and transfer it to a narrow-mouth glass bottle of about 30 mL. This gives the upper-layer sample.
  • 7.8.2 Place the pipette tip accurately at the 15 mL mark of the graduated cylinder, slowly draw 10 mL of sample and transfer it to a narrow-mouth glass bottle of about 30 mL. This gives the lower-layer sample.
• 7.9 Shake the upper-layer and lower-layer samples separately to mix them uniformly, use a microsyringe to draw 0.5 μL of sample, and determine the water content of the upper and lower layers according to SH/T 0246 [%(m/m)].

9. Qualitative and quantitative determination and calculation formulas

• Test items: oil separation amount [%(V/V)], water separation amount [%(V/V)], upper-layer water content [%(m/m)], lower-layer water content [%(m/m)].
• Water content determination shall be carried out according to SH/T 0246.
• Calculation formulas: not provided in the available source.

10. Precision

• 9.1 Type I — stable emulsion

  • Note: A sample whose water separation amount after the nine-cycle test is less than 10%(V/V), and whose difference between upper and lower layer water contents is relatively small, with a ratio greater than 0.9.
  • Judge the reliability of test results according to the following provisions (95% confidence level).
  • 9.1.1 Repeatability: The difference between two results obtained by the same operator in repeated determinations shall not exceed the value specified for repeatability in the table below.
  • 9.1.2 Reproducibility: The difference between two results submitted by different laboratories shall not exceed the value specified for reproducibility in the table below.

  Precision table for Type I

  Item	Repeatability	Reproducibility
  Oil separation amount, %(V/V)	1	2
  Water separation amount, %(V/V)	1	2
  Difference in ratio of upper and lower layer water contents, %	3	3

  • Note: The above precision provisions were obtained from statistical testing of interlaboratory test results on water-in-oil emulsion hydraulic fluids with a water content of 35%—50%(m/m).

• 9.2 Type I — unstable emulsion

  • Note: A sample whose water separation amount after the nine-cycle test exceeds 10%(V/V).
  • The degree of instability of the sample caused by temperature cycling varies considerably, so precision is temporarily not specified.

11. Report

• 8.1 Oil separation amount [%(V/V)].
• 8.2 Water separation amount [%(V/V)].
• 8.3 Upper-layer water content [%(m/m)].
• 8.4 Lower-layer water content [%(m/m)].

12. Referenced documents

• SH/T 0246 Determination of water content in light petroleum products (coulometric method)
• ASTM D3709-89 (reference adoption)

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 Q&A