SH/T 0037-1990 Determination of Storage Dissolution Characteristics of Gear Oils

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Card type: Test method

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

• Standard number: SH/T 0037—1990 (confirmed in 2006)
• Chinese name: Determination of Storage Dissolution Characteristics of Gear Oils
• English name: not provided in the available source
• Replacement relationship: not provided in the available source
• Reference adoption: United States Federal Standard FTM 791 b3440 "Test Method for Storage Dissolution Characteristics of Universal Gear Oils" (see additional notes)
• Approval/implementation: approved by China Petrochemical Corporation 1991-03-27, implemented on 1992-04-01

2. Scope of application and non-applicability

• Scope of application: This standard applies to gear oils.
• Non-applicability: not provided in the available source.

3. Method principle

Pour the 220mL test sample into a beaker, heat it at the specified temperature and for the specified time, cool it to room temperature, then pour it into two conical centrifuge tubes. After storage at room temperature for 30d (or 60d), separate the non-oil-soluble insoluble matter with a centrifuge. If the insoluble matter is liquid, directly record the volume; if the insoluble matter is solid, it must be washed with solvent, dried, and weighed, and the mass recorded. Report the determination result as a volume or mass percentage. (Chapter 3)

4. Reagents and materials (purity / preparation)

• 5.1 Petroleum ether: 60~90°C, analytical reagent.
• 5.2 Potassium dichromate: prepare as cleaning solution.
• 5.3 95% ethanol: chemical reagent.
• 4.2 Material Solvent: quality meets the requirements of Table 2.

Table 2 Solvent quality requirements

(Note: The correspondence between "90~95" and "not less than" in Table 2 is transcribed as in the original text and requires confirmation against the source standard (source-text extraction).)

5. Instruments and equipment

• 4.1.1 Centrifuge:
  • 4.1.1.1 Capable of rotating two or more conical centrifuge tubes of about 203mm filled with test sample, and capable of controlling the rotational speed so that the relative centrifugal force at the end of the centrifuge tube is at least 500.
  • 4.1.1.2 The rotating head, centrifuge cups, and centrifuge rings, including cushion pads, shall have good construction so as to withstand the maximum centrifugal force from the power source. During centrifugation, the bottom gasket and upper gasket of the centrifuge cup shall firmly support the centrifuge tube. The centrifuge shall be enclosed by a sufficiently sturdy metal guard to prevent danger if a centrifuge tube breaks.
  • 4.1.1.3 The centrifuge and motor shall comply with the relevant laboratory safety regulations.
  • 4.1.1.4 The centrifuge speed per minute n (r/min) is calculated according to formula (1): the original formula is "500 / 1=1337 ⋯… (1)", where: 500— relative centrifugal force; d— under rotation, the rotational diameter between the tips of opposite tubes, mm. The formula layout is suspected to have source-text extraction missing and requires confirmation against the source standard (source-text extraction).
• 4.1.2 Centrifuge tube: conical, dimensions meet the requirements of the figure below, and the centrifuge tube shall be fully annealed. The scale numbers shall be clear and distinct, and the mouth of the centrifuge tube may be tightly closed with a stopper. The allowable tolerance of the scale and the minimum scale between marks are given in Table 1, and may be calibrated with freshly boiled 20°C distilled water, reading at the lower edge of the meniscus.
  • Centrifuge tube figure annotations (source-text extraction): inner ¢16–18; 100mL; 75; 50; 195–203; outer ¢36.00–37.75; 10mL; 13; 15; the side of the cone must be straight; 1mL; 22.5–24.5; upper inner bottom line; the tip of the centrifuge tube.
• 4.1.3 Conical flask: 250mL.
• 4.1.4 Beaker: tall form, 400mL.
• 4.1.5 Desiccator: can hold several centrifuge tubes.
• 4.1.6 Oven: temperature adjustable at 105°C±3°C.
• 4.1.7 Balance: sensitivity 1mg.

Table 1 Allowable tolerances for calibration of centrifuge tubes

(Note: Symbols such as "•0.5" and "‡0.02" in Table 1 are source-text extraction noise, organized according to context as "0.5" and "±0.02", and require confirmation against the source standard (source-text extraction).)

6. Recommended operating conditions

• Sample heating: 121°C±1°C, hold for 20min, then cool to 25°C±3°C (6.2).
• Storage: room temperature, upright, protected from light, 30d (6.3); if necessary, a second storage period for another 30d (6.5.3, 6.6).
• Centrifugation: centrifuge at the speed calculated according to formula (1) for 30min (6.4); after washing, centrifuge again for 15min (6.5.1); for loose insoluble matter, continue centrifuging for 15min (6.5.2).
• Drying: 105°C±3°C, 1.5h (6.1b, 6.5.4).
• Cooling in desiccator: 30min (6.1c, 6.5.5).
• Weighing: weigh to 0.001g (6.1d, 6.5.5).
• Volume reading of liquid insoluble matter: read to 0.05mL (6.6).

7. Sampling and test sample preparation

• 6.2 Take 220mL of an unstored, freshly prepared test sample, place it in a 400mL beaker, heat to 121°C±1°C, hold for 20min, then allow it to cool to 25°C±3°C.
• 6.3 Add 100mL of the heated test sample to each of two weighed centrifuge tubes, close tightly with stoppers, store upright on a centrifuge tube rack at room temperature, protected from light, for 30d.

8. Analytical procedure

• 6.1 Prepare two centrifuge tubes according to the following procedure:
  • a. First wash the centrifuge tubes with petroleum ether and potassium dichromate cleaning solution, then rinse with distilled water and 95% ethanol;
  • b. Place the cleaned centrifuge tubes inverted in an oven and dry at 105°C±3°C for 1.5h;
  • c. Remove the centrifuge tubes from the oven, place them in a desiccator, and cool for 30min;
  • d. Weigh the centrifuge tubes to 0.001g, and before use, they shall be kept in a desiccator.
• 6.2 Test sample heating treatment (see Section 7).
• 6.3 Tube filling and storage (see Section 7).
• 6.4 After storage is completed, remove the centrifuge tubes from the storage room (care must be taken not to disturb the insoluble matter), and centrifuge at the speed calculated according to formula (1) for 30min. After rotation stops, remove the centrifuge tubes.
• 6.5 If the insoluble matter in the centrifuge tube is solid, proceed as follows:
  • 6.5.1 If after centrifugation the insoluble matter is a compact solid, pour off the upper oil layer in the centrifuge tube, then place the centrifuge tube vertically inverted on a conical flask to drain for 2h. Wash each centrifuge tube with solvent, and use a clean iron wire to stir and disperse the insoluble matter, then centrifuge again for 15min. After centrifugation, pour off the upper clear liquid as much as possible, but do not disturb the insoluble matter. Repeat the washing several times until the insoluble matter contains no oil.
  • 6.5.2 If after centrifugation the insoluble matter is loose, gently pour off the upper oil, continue centrifuging for 15min, then pour off the upper oil again. Repeat in this way until the oil is completely poured off, then proceed according to 6.5.1.
  • 6.5.3 If after centrifugation the insoluble matter is still suspended, close the stopper tightly, return it to the original storage location, and store again for 30d. After the second storage period ends, proceed according to clauses 6.4 and 6.5.1.
  • 6.5.4 Place the centrifuge tube vertically in an oven, adjust the temperature to 105°C±3°C, and dry for 1.5h.
  • 6.5.5 Remove the centrifuge tube from the oven, place it in a desiccator to cool for 30min, weigh the centrifuge tube to 0.001g, subtract the mass of the empty tube to obtain the mass of the insoluble matter.
• 6.6 If after centrifugation the insoluble matter is liquid, close the stopper tightly, return it to the original storage location, and continue storing for 30d. After the second storage period ends, after treatment according to clause 6.4, directly read the volume of liquid insoluble matter from the centrifuge tube, reading to 0.05mL.

9. Qualitative and quantitative determination and calculation formulas

• 7.1 When the separated insoluble matter is solid, the average value of the mass of insoluble matter in the test sample m (g) is calculated according to formula (2):
  • Original formula: m = (m₁ + m₂) / 2 ⋯ (2)
  • Where: m₁, m₂—respectively represent the mass of insoluble matter in the two centrifuge tubes, g.
• The insoluble matter in the test sample X₁ [% (m/m)] is calculated according to formula (3):
  • Original formula: X₁ = 0.9 × Y₁ × 100 ⋯ (3)
  • Where: 0.9— the average relative density of the test sample; Y₁—100g the mass of the additive contained in the test sample, g.
  • (Note: the original layout of formula (3) appears to have omissions; requires confirmation against the source standard (source-text extraction).)
• 7.2 When the separated insoluble matter is a liquid, the average value of the volume of insoluble matter in the test sample V (mL) is calculated according to formula (4):
  • Original formula: V = (V₁ + V₂) / 2 ⋯ (4)
  • Where: V₁, V₂—respectively represent the volumes of insoluble matter in the two centrifuge tubes, mL.
• The insoluble matter in the test sample X₂ [% (V/V)] is calculated according to formula (5):
  • Original formula: X₂ = V / Y₂ × 100 ⋯ (5)
  • Where: Y₂—100mL the volume of the additive contained in the test sample, mL.
  • (Note: the original layout of formula (5) appears to have omissions; requires confirmation against the source standard (source-text extraction).)

10. Precision

not provided in the available source.

11. Report

Report the mass percentage or volume percentage of insoluble matter in the test sample, and indicate solid or liquid. (Chapter 8)

12. Normative references

• GB/T 1884 Standard test method for density of crude petroleum and liquid petroleum products (hydrometer method)
• GB/T 3555 Standard test method for Saybolt color of petroleum products (Saybolt chromometer method)
• GB/T 6536 Standard test method for distillation of petroleum products
• Editor's note: In this standard, the standard numbers and standard names of the referenced standards have changed as follows: original standard number GB/T 6536, current standard number GB/T 6536, current standard name Standard test method for distillation characteristics of petroleum products at atmospheric pressure.

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 for questions and answers