GB/T 392-1977 Determination of oil separation from lubricating grease under pressure

AI-translated method card — human verification pending. This is not an official translation of the standard. Unclear source values remain unverified; check the original standard and product certificate before use.

Card type: Test method

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

• Standard number: GB 392-77 (confirmed in 1982)
• Chinese title: Determination of oil separation from lubricating grease under pressure
• English title: Lubricating grease — Determination of oil separation — Pressure method (original spelling is “Lubricating Brease-Deteru ination of oll separatlon—Pressure method”, requires confirmation against the source standard (source-text extraction))
• Supersession relationship: supersedes GB 392-64
• Issued/implemented: issued by the National Bureau of Standards and Metrology 1977-11-08, implemented 1978-01-01

2. Scope of application and non-applicability

• Scope of application: This method is applicable to the determination of the oil separation amount of lubricating grease.
• Not applicable: not provided in the available source.

3. Method principle

• This method uses a pressure oil separator to press oil out of the lubricating grease, and then determines the amount of oil pressed out. (Original Chapter 1 Method summary)

4. Reagents and materials (purity / preparation)

• Reagents: industrial solvent naphtha, petroleum ether (60~90°C) or benzene (chemically pure). (Original Chapter 3)
• Materials:
  • Lubricating oil: use lubricating oil corresponding to the base oil in the sample. (2.2.1)
  • Quantitative filter paper: rapid, diameter 55 millimeters. (2.2.2)
• Preparation: not provided in the available source.

5. Apparatus and equipment

• Pressure oil separator (Figure 1), consisting of the following parts: pressure oil separator stand, with a glass plate attached (Figure 2); connecting rod, with a shoulder for fixing the weight (Figure 3); metal ball, used to transmit pressure, diameter 8 millimeters; dish for holding the lubricating grease, with a sleeve on the dish for the piston handle to pass through (Figure 4); piston inserted in the dish, with a side recessed flat surface on the piston handle to prevent a vacuum from forming above it when the piston is pressed down (Figure 5); level. Among these: the total weight of the connecting rod, metal ball, piston and weight is 1000±10 grams (original text is “100010 grams”, requires confirmation against the source standard (source-text extraction)). (2.1.1)
• Water bath: diameter not less than 170 millimeters, height not less than 70 millimeters, containing a metal cup with a diameter of about 65 millimeters and a height of about 65 millimeters and a cover, with a hole in the cover for the connecting rod to pass through, and a glass sheet placed at the bottom of the cup. (2.1.2)
• Mercury thermometer: 0~100°C, graduation 1°C. (2.1.3)
• Stopwatch or watch. (2.1.4)
• Spatula. (2.1.5)

6. Recommended operating conditions

• Room temperature conditions: when the room temperature is 15~25°C, carry out the determination on the glass plate of the pressure oil separator. (4.5)
• Constant-temperature water bath conditions: when the room temperature is lower than 15°C or higher than 25°C, the determination should be carried out in a constant-temperature water bath, with the water bath temperature maintained at 20±2°C; place 10 sheets of filter paper and the dish containing the sample in sequence in the water bath metal cup, cover with the cup cover, keep at constant temperature for 30 minutes, then carry out the determination. (4.5)
• Pressurization time: 30 minutes. (4.7)
• Instrument level: use a level to check whether the instrument stand is level. (4.6)

7. Sampling and sample preparation

• Wash the dish with piston with solvent, dry it, and set aside for use. (4.1)
• Cut 1 sheets of filter paper equal to the outer diameter of the dish, wet them with lubricating oil, then sandwich them between 2 sheets of clean filter paper and absorb the excess oil. (4.2)
• Weigh the above-prepared dish and filter paper together, accurate to 0.0002 grams. (4.3)
• Use a spatula to apply the sample into the dish with piston, without forming bubbles or voids; press the oil-impregnated filter paper tightly onto the surface of the sample, without leaving gaps, then weigh again, accurate to 0.0002 grams. (4.4)

8. Analysis procedure

• 4.1 Wash the dish with piston with solvent, dry it, and set aside for use.
• 4.2 Cut 1 sheets of filter paper equal to the outer diameter of the dish, wet them with lubricating oil, then sandwich them between 2 sheets of clean filter paper and absorb the excess oil.
• 4.3 Weigh the above-prepared dish and filter paper together, accurate to 0.0002 grams.
• 4.4 Use a spatula to apply the sample into the dish with piston, without forming bubbles or voids; press the oil-impregnated filter paper tightly onto the surface of the sample, without leaving gaps, then weigh again, accurate to 0.0002 grams.
• 4.5 When the room temperature is 15~25°C, stack 10 sheets of clean filter paper on the glass plate of the pressure oil separator, and place the dish on top of the filter paper layers. When the room temperature is lower than 15°C or higher than 25°C, the determination should be carried out in a constant-temperature water bath, and the water bath temperature should be maintained at 20±2°C. In the water bath, place 10 sheets of filter paper and the dish containing the sample in sequence in the round cup, cover with the cup cover, keep at constant temperature for 30 minutes, then carry out the determination.
• 4.6 Use a level to check whether the instrument stand is level, then place a metal ball for transmitting pressure in the round recess of the piston handle, insert the connecting rod and weight from the lower end of the hole in the pressure oil separator stand, press them onto the ball on the piston handle, and start timing at the same time.
• 4.7 After 30 minutes, remove the connecting rod, weight and metal ball. Then weigh together the dish containing the sample and the 1 sheets of oil-impregnated filter paper originally attached to the surface of the sample, accurate to 0.0002 grams.

9. Qualitative and quantitative determination and calculation formula

• The weight of oil separated from the sample due to pressing X (%) is calculated according to the following formula:

  X = (G₂ − G₃) / (G₂ − G₁) × 100

  The original formula source-text extraction is “X=29-9×100 / G-G,”, requires confirmation against the source standard (source-text extraction).

• Where:

  • G₁: weight of the dish without sample and 1 sheets of oil-impregnated filter paper, grams;
  • G₂: weight of the dish containing the sample and 1 sheets of oil-impregnated filter paper before the test, grams;
  • G₃: weight of the dish containing the sample and 1 sheets of oil-impregnated filter paper after the test, grams.

10. Precision

• The difference between the two results of repeated determinations and the arithmetic mean shall not exceed ±5% of the arithmetic mean. (Original Chapter 6)

11. Report

• Take the arithmetic mean of the two results of repeated determinations as the test result. (Original Chapter 7)

12. Referenced documents

• not provided in the available source.

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