SH/T 0722-2002 Determination of High Temperature Foaming Characteristics of Lubricating Oils

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Card type: Test method

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

• Method number: SH/T 0722—2002
• Chinese full name: Determination of High Temperature Foaming Characteristics of Lubricating Oils
• English name: Standard test method for high temperature foaming characteristics of lubricating oils (the original title bar also shows spelling noise "higch bemperature", requires confirmation against the source standard (source-text extraction))
• Replacement relationship: not provided in the available source (the foreword only states equivalent adoption of ASTM D 6082-00, and does not mention replacement of an old standard)
• Adoption relationship: equivalent adoption of ASTM D 6082-00 "Determination of High Temperature Foaming Characteristics of Lubricating Oils"
• Publication/implementation: published on 2002-05-31, implemented on 2002-07-01; publishing unit: State Economic and Trade Commission
• Custodianship: Sinopec Research Institute of Petroleum Processing; drafting unit same as above; main drafters: Chen Jie, Guo Tao

2. Scope of application and non-applicability

• 1.1 This standard specifies the method for determining the foaming characteristics of lubricating oils (specifically transmission fluids and engine oils) at 150 ℃.
• 1.2 The foaming characteristics of lubricating oils at 93.5 ℃ are determined by the method of GB/T 12579 (that is, they are not within the scope of application of this standard).
• 1.3 This standard involves certain hazardous materials, operations and equipment, but it is not intended to address all safety issues associated with them; users should establish appropriate safety and protective measures and determine applicable management systems before use.

3. Method principle

• Chapter 4 Method summary: Heat the sample to 49 ℃, hold at constant temperature for 30 min, then cool to room temperature, then transfer the sample to a graduated 1000 mL cylinder, and heat to 150 ℃, pass dry air into the metal diffuser at a flow rate of 200 mL/min, aerate for 5 min, determine the static foam volume immediately before stopping aeration, the dynamic foam volume, and the static foam volume at the specified time after stopping aeration (see Chapter 10), the foam collapse time, and the total volume increase percentage.

4. Reagents and materials (purity / preparation)

• Chapter 7: The chemical reagents used in this standard shall generally be analytical grade unless otherwise specified.
• 7.1 Acetone. Warning: extremely flammable, its vapor can cause flash fire.
• 7.2 Compressed air: dry hydrocarbon-free gas, dew point −60 ℃ or lower.
• 7.3 n-Heptane. Warning: flammable, vapor harmful.
• 7.4 Isopropanol. Warning: flammable, vapor harmful.
• 7.5 Toluene. Note: Toluene may be used as a cleaning reagent. Warning: flammable, vapor harmful.
• Bath liquid (6.1.1): a liquid that has low volatility at the test temperature, stable chemical properties, and sufficiently low viscosity to allow stirring; Note 1: Poly α-olefin with a kinematic viscosity of 4 mm²/s~7 mm²/s is suitable as a bath liquid; the use of silicone oil is discouraged (silicone oil is a foam inhibitor and may cause changes in the foaming characteristics of the sample); Note 2: Slowly blow nitrogen into the liquid, such as covering the bath liquid surface with a blanket, to reduce darkening of the bath liquid (oxidation).
• Preparation: not provided in the available source (no standard solution preparation steps are given).

5. Apparatus and equipment

• 6.1 Heating bath: the heating system can maintain the sample temperature at 150 ℃±1 ℃ (see Figure 2). Note: The precision of this method applies only to liquid baths.
• 6.1.1 Bath liquid: see Section 4.
• 6.2 Cylinder: graduated 1000 mL cylinder, with graduations of 10 mL. If a liquid bath is used, a device capable of overcoming buoyancy and a stopper should be fitted to the cylinder; the cylinder should be able to withstand the high temperature required by the test method. Note 1: A sufficiently heavy metal ring is placed on the outside of the bottom of the cylinder to overcome buoyancy. Note 2: A graduated round-mouth cylinder may be made by cutting off the spout of a spouted cylinder; the cut edge must be smoothed by flaming or grinding.
• 6.3 Flowmeter: calibrated, and capable of maintaining an air flow rate of 200 mL/min±5 mL/min.
• 6.3.1 Gas flowmeter with a minimum scale of 10 mL or other equivalent flow measuring device, requiring a measured flow rate of at least 6000 mL/min, and generating a back pressure not greater than 98.07 Pa (10 mmH₂O).
• 6.4 Oven: without fan, and capable of controlling temperature at 49 ℃±1 ℃.
• 6.5 Stirrer: rotation speed 500 r/min±100 r/min, equipped with a marine-type propeller with three blades of length 3.8 cm.
• 6.6 Metal diffuser: 5 μm porous stainless steel diffuser. Its maximum pore diameter determined according to the method in Appendix A is 15 μm–60 μm, and permeability is 3000 mL/min–6000 mL/min (see Figure 3).
• 6.6.1 New diffusers or each batch of diffusers after use (used 10 times or fewer) should be calibrated and standardized.
• 6.7 Thermometer: capable of measuring temperature 150 ℃±0.2 ℃, meeting the requirements of Appendix B or an equivalent thermometer.
• 6.8 Timer: minimum division value 1 s.
• 6.9 High-speed stirrer: stirring capacity 1 L, stirring speed can reach 22000 r/min±2000 r/min.
• Appendix A Apparatus: A1.1 Maximum pore diameter measuring apparatus (clean, dry, controllable compressed air source, length at least 500 mm readable 7.85 kPa (800 mmH₂O) pressure difference U-type tube manometer, about 250 mL cylinder that can conveniently immerse the diffuser to a depth of 100 mm); A1.2 Permeability measuring apparatus (wet flowmeter with a back pressure not greater than 98.07 Pa (10 mmH₂O) at a flow rate of 6000 mL/min, suction flask capable of conveniently inserting a diffuser of diameter 25.4 mm into the neck, single-hole stopper, connecting tube with inner diameter 8 mm).
• Appendix B Thermometer: glass mercury thermometer, meeting the requirements of Table B1 (range 98 ℃–152 ℃, immersion depth 100 mm, division value 0.2 ℃, long line interval 1 ℃, numbered scale interval 2 ℃, scale error not exceeding 0.3 ℃, expansion chamber allowed to be heated to 180 ℃, total length 390 mm–400 mm, stem outer diameter 6.0 mm–8.0 mm, mercury bulb length 15 mm–20 mm, mercury bulb outer diameter not greater than stem outer diameter, distance from mercury bulb bottom to line 98 ℃ is 125 mm–145 mm, scale portion length 190 mm–235 mm, distance from contraction chamber to top of mercury bulb not greater than 35 mm; Note: At 0 ℃ the mercury column should be close to the bottom of the contraction chamber).

6. Recommended operating conditions

• Test temperature: 150 ℃±1 ℃ (6.1, 10.6, 10.7, 10.8, 10.9).
• Air flow rate: 200 mL/min±5 mL/min (6.3, 10.9).
• Aeration time: 5 min±10 s (10.9).
• Preheating conditions: 49 ℃±3 ℃ oven heating 30 min (10.3); cooling to room temperature 24 ℃±3 ℃ (10.4).
• Stirring conditions (optional): 500 r/min±100 r/min stirring 60 s±10 s (10.2); high-speed stirring 22000 r/min±2000 r/min stirring 1 min (10.2.1).
• Cylinder immersion: immersed at least to the 900 mL mark, completed within 1 h for 10.9 strips (10.6).
• Diffuser position: in contact with the center bottom of the cylinder, maintained at least 5 min below 150 ℃±1 ℃ (10.8).
• Compressed air: dry, hydrocarbon-free, dew point −60 ℃ or lower (7.2).

7. Sampling and sample preparation

• 10.1 According to the lubricant specification requirements, if stirring needs to be selected, it should be carried out according to 10.2.1. Note: When the lubricant specification requires the use of procedure A to select stirring, it refers to step 10.2.1.
• 10.2 Vigorously shake the sample container for 1 min, take about 200 mL of sample and pour it into a 400 mL beaker. Stir the sample with a stirrer at 500 r/min±100 r/min for 60 s±10 s; if stirring is not required, proceed according to clause 10.3.
• 10.2.1 Stirring (optional): clean a container with a capacity of 1 L and a high-speed stirrer (see clause 6.9), shake the sample vigorously 1 min, pour the 500 mL sample into the container, cover the container, and stir the sample at a speed of 22000 r/min±2000 r/min for 1 min. Because a large amount of air is present as entrained bubbles during this stirring process, it is necessary to let it stand under 24 ℃±3 ℃ until the entrained bubbles disperse and the oil temperature reaches 24 ℃±3 ℃. After stirring, within 3 h, continue the test according to clause 10.3.
• 10.2.2 If the sample is a viscous oil, if the bubbles have not completely disappeared within 3 h, a longer time is required, and this time should be recorded and stated when reporting the results.
• 10.3 Heat the sample in an oven at 49 ℃±3 ℃ for 30 min.
• 10.4 Cool the sample to room temperature (24 ℃±3 ℃); the test should be carried out within 3 h after heating is stopped.
• 10.5 In a graduated 1000 mL cylinder, add the sample so that its liquid level reaches 180 mL.

8. Analytical Procedure

• 10.6 Immerse the cylinder in a bath capable of maintaining the sample at 150 ℃±1 ℃, and immerse it at least to the 900 mL mark, and complete clause 10.9 within 1 h. Care should be taken when placing the cylinder into the solution; the cylinder should be lowered slowly to avoid bursting the cylinder.
• 10.7 From time to time, immerse a thermometer or other temperature sensor into the sample to measure the sample temperature and ensure that the sample temperature reaches 150 ℃±1 ℃.
• 10.8 With the gas inlet tube disconnected, immerse the gas diffusion head into the sample, adjust the position of the diffusion head so that it contacts the center bottom of the cylinder, and when the sample temperature reaches 150 ℃±1 ℃, maintain it for at least 5 min.
• 10.9 After the diffusion head has been kept in the sample at 150 ℃±1 ℃ for 5 min, record the initial total volume of the test (Vᵢ), accurate to 10 mL. Connect the gas inlet tube to the gas diffusion head, adjust the gas flow rate to 200 mL/min±5 mL/min, and pass gas for 5 min±10 s.
• 10.10 At the instant before stopping the gas flow, record the final total volume (V_f), static foam volume, and dynamic foam volume, accurate to 10 mL (see Figure 1).
• 10.11 After cutting off the air source, record the static foam volume at the specified times as follows, mL (see Figure 1): 5 s (±1.0 s), 15 s (±1.0 s), 1 min (±1.0 s), 5 min (±1.0 s), 10 min (±1.0 s). *For some oils, the bubbles disappear very quickly, and it is difficult to obtain foam readings at 5 s and 15 s.
• 10.12 Record the time required for the foam to disappear to "0" (foam disappearance time), accurate to ±1 s.
• 9.1 Apparatus preparation (cleaning after test): after each test, the cylinder, gas diffusion head, and air inlet tube should be thoroughly cleaned.
  • 9.1.1 Cylinder: clean with n-heptane, then blow dry directly with compressed air, then clean with a suitable cleaning agent, then rinse successively with distilled water and acetone, and finally blow dry with compressed air or dry in an oven. When the distilled water on the inner wall of the cylinder can drain cleanly and no water droplets form, it is considered clean. Note: Some cleaning agents will adhere to the glass and may affect the test results, so rinsing separately with water and acetone is necessary.
  • 9.1.2 Gas diffusion head and inlet tube: clean with toluene and n-heptane. Immerse the gas diffusion head in about 300 mL of toluene, and make it pass through the inlet tube by suction and pressure, then rinse the diffusion head with toluene at least 5 times. Repeat this process with n-heptane, and finally dry the gas diffusion head by passing clean compressed air through the inlet tube. The outside of the inlet tube should first be cleaned with toluene, then wiped with a silk cloth moistened with n-heptane, and finally wiped dry with a dry silk cloth, taking care not to wipe the diffusion head. Note: Some samples may still contain components that cannot be removed after this process, which may affect the next test, so more stringent cleaning is required; when changing the cleaning method for the diffusion head, the final cleaning method should be carried out according to 9.1.2; the permeability and pore size of the gas diffusion head may change after use, so new diffusion heads or used diffusion heads should be calibrated and standardized regularly (preferably after each use) (see Appendix A).
• Appendix A Procedure:
  • A2.1 Maximum pore diameter: use a tube 1 m long with an inner diameter of 8 mm to connect the diffusion head to a differential pressure gauge, and immerse the diffusion head in an isopropanol solution, with the top of the diffusion head 100 mm from the liquid surface, immersed for about 2 min, and connect the inlet tube to the gas source as shown in Figure A1. Increase the air pressure at a rate of 490 Pa (50 mmH₂O)/min until the first dynamic bubble passes through the isopropanol, and immediately record the water level pressure difference p between the two arms of the differential pressure gauge. By gradually increasing the pressure, the uniformity of the pore distribution near the maximum pore diameter can be observed, and attention should be paid to the uniformity of the bubble string distribution.
  • A2.2 Permeability: use a tube 1 m long with an inner diameter of 8 mm to connect a clean, dry diffusion head to a clean, dry controlled compressed air source, and then use a tube 0.5 m long to connect a suction flask to a wet flow meter (see Figure A2), adjust the pressure difference to 2.45 kPa (250 mmH₂O), and measure the air flow rate through the gas diffusion head. Depending on the sensitivity of the flow meter used, a longer observation record should be made to obtain the average flow rate per minute.

9. Qualitative and Quantitative and Calculation Formulas

• 11.1 The increase in total volume ΔV (mL) is calculated according to formula (1): ΔV = V_f − Vᵢ
  • Where: V_f— final total volume obtained in the test, mL; Vᵢ—initial total volume at the time of the test, mL.
• 11.2 The percentage increase in total volume ΔV% is calculated according to formula (2): ΔV% = (V_f − Vᵢ)/Vᵢ×100
• Appendix A2.1.1 The maximum pore diameter of the diffusion head D (μm) is calculated according to formula (A1): D = 8930/ (p·80) (original text as such, requires confirmation against the source standard (source-text extraction): the denominator form is suspected to be erroneous)
  • Where: p— water column pressure difference, mmH₂O.
• Term definitions (Chapter 3, for qualitative interpretation): 3.1 diffusion head; 3.2 entrained air (or gas) (bubble diameter 10 μm–1000 μm, original text "10yum–1000pum" requires confirmation against the source standard (source-text extraction)); 3.3 foam; 3.4 gas; 3.5 lubricant; 3.6 zero foam; 3.7 foam disappearance time (the time at which zero foam appears after cutting off the air source, in s); 3.8 static foam; 3.9 foam stability; 3.10 five-second foam stability; 3.11 fifteen-second foam stability; 3.12 one-minute foam stability; 3.13 five-minute foam stability; 3.14 ten-minute foam stability; 3.15 foam tendency (the amount of static foam at the instant before stopping the gas flow); 3.16 dynamic foam; 3.17 percentage increase in volume (the percentage of the increase in total volume at the test temperature relative to the original volume including the volume of the diffusion head); 3.18 total volume; 3.19 initial total volume (Vᵢ); 3.20 final total volume (V_f); 3.21 top volume; 3.22 bottom volume; 3.23 maximum pore diameter; 3.24 permeability (2.45 kPa gas flow rate through the diffusion head under gas pressure, mL/min); 3.25 dynamic bubble.

10. Precision

• Chapter 13: Judge the reliability of test results according to the following provisions (95% confidence level). Note: The precision of foam stability at different times without stirring is under study.
• 13.1 Repeatability (r): The difference between two results obtained by the same operator using the same apparatus under the same operating conditions on the same sample shall not exceed the value in Table 1.
• 13.2 Reproducibility (R): The difference between two results obtained by different operators in different laboratories on the same sample shall not exceed the value in Table 1.
• Note: The values in Table 1 apply only to passenger car engine oils.
• Table 1 Repeatability and reproducibility of lubricating oil high-temperature foam test (original values contain source-text extraction noise, requires confirmation against the source standard (source-text extraction)):

• Note: X is the average of two determination results.

11. Report

• Chapter 12 reports the following contents:
  • Whether 12.1 selects stirring;
  • 12.2 foam tendency (the volume of static foam at the instant before stopping aeration), accurate to 10 mL;
  • 12.3 the volume of moving foam (the volume of moving foam at the instant before stopping aeration), accurate to 10 mL;
  • 12.4 final total volume (V_f), accurate to 10 mL;
  • 12.5 foam stability (the static foam volume at the specified time after disconnecting air), accurate to 10 mL;
  • 12.6 foam disappearance time, s;
  • 12.7 total volume increase (ΔV), mL;
  • 12.8 total volume increase percentage (ΔV%), %.
• See also 10.2.2: when the foam of viscous oil does not completely disappear within 3 h, this time should be recorded and explained when reporting the results.

12. Normative references

• Chapter 2 referenced standards: the provisions included in the following standards constitute a part of this standard through reference. Unless otherwise explicitly specified in this standard, the following referenced standards shall all be currently effective standards.
  • GB/T 12579 Determination of foaming characteristics of lubricating oils
• Foreword: the referenced standards of this standard adopt the corresponding currently effective standards of our country; where there is no corresponding standard, their substantive content is adopted.
• Appendix A and Appendix B are both normative appendices.

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 Q&A reference