SH/T 0323-1992 (2004) Determination of the ultimate strength of lubricating grease

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 name / English name / replacement relationship

• Standard number: SH/T 0323-92 (confirmed in 2004)
• Full name: Determination of the ultimate strength of lubricating grease
• English name: not provided in the available source
• Replacement relationship: replaces ZB E36 015-88
• First issued: 1965
• Technical administration: under the technical administration of the Research Institute of Petroleum Processing
• Drafting: drafted under the responsibility of the Research Institute of Petroleum Processing

2. Scope of application and non-applicability

• Scope of application: This standard specifies the method for determining the ultimate strength of lubricating grease; it is applicable to the determination of the ultimate strength of lubricating grease using a plastometer.
• Non-applicability: not provided in the available source.

3. Method principle

At the test temperature, measure the pressure at which the lubricating grease undergoes displacement in the threaded tube of the plastometer, convert it into an ultimate strength value, and express it as Pa.

4. Reagents and materials (purity / preparation)

• 4.1 (original number 3.1) Rubber industry solvent naphtha.
• 4.2 (original number 3.2) 40℃ lubricating oil with a kinematic viscosity of 24~90 mm²/s and a pour point lower than the test temperature 15℃.
• Purity and specific preparation method: not provided in the available source.

5. Instruments and equipment

• 4.1 Ultimate strength tester: composed of the following components (see Figure 1).
  • 4.1.1 Electric furnace: used to heat the oil reservoir, 220V, 70W.
  • 4.1.2 Oil reservoir.
  • 4.1.3 Pressure gauge: expansion tube, diameter not greater than 100mm, pressure gauge range and allowable measurement range are shown in the table below (unit MPa):

• 4.1.4 Oil supply funnel.
• 4.1.5 Valve: capable of connecting and cutting off the oil supply funnel and the internal pipe system.
• 4.1.6 Connecting pipe.
• 4.1.7 Glass cover.
• 4.1.8 Nut: used to fix the threaded tube.
• 4.1.9 Housing: used to hold the threaded tube.
• 4.1.10 Threaded tube (see Figure 2) and sleeve: divided into long and short sets, the long threaded tube is 100mm, the short threaded tube is 50mm, with two of each. The threaded tube is formed by tightly joining two longitudinally split tubes. The inner diameter of the tube is 4mm, and the inner wall of each tube has spiral threads, with a tooth spacing of 0.8mm.
• 4.2 Worker: used to stir the sample. Inner diameter 40mm, height 60mm. The lid and bottom of the worker can be removed. The worker is equipped with a piston having 40 holes (hole diameter 3mm). It is also permissible to use a worker with a lined cylinder, which can reduce the volume of the worker by half.
• 4.3 Scraper.
• 4.4 Constant-temperature bath.
• 4.5 Stopwatch.

6. Recommended operating conditions

• Test temperature: according to the product standard, make the test temperature accurate to 1℃ and keep constant temperature for 20min (see 5.13).
• The liquid level of the constant-temperature bath should exceed the top of the threaded tube by 30mm (see 5.12).
• Pressurization rate: when using the long threaded tube, the system pressurization rate per minute should not exceed 0.005MPa; when using the short threaded tube, it should not exceed 0.0025MPa per minute (see 6.1).
• The interval from completion of sample stirring to the start of the test should be within 30~40min (see 5.13).
• When testing with the long threaded tube and the pressure exceeds the allowable value of the pressure gauge, the short threaded tube should be used (see 5.13).

7. Sampling and sample preparation

• 5.1 Fill the entire system of the apparatus, including the pressure gauge and pipelines, with lubricating oil.
• 5.2 All plastometer parts and the worker that come into contact with the sample shall be wiped clean with solvent naphtha and dried.
• 5.3 Use a scraper to fill the worker with the sample, and no bubbles or voids shall be formed.
• 5.4 Close the lid and bottom of the worker. Before tightening the top cover, the small holes in the piston should be filled with sample to avoid introducing air into the sample. Then screw on the bottom cover and top cover.
• 5.5 Keep the worker containing the sample in a constant-temperature bath at 20℃±1℃ for 30min, then pull the hole plug back and forth 100 times.
• 5.6 Open the top cover of the worker, and carefully spread the sample vertically with a scraper into the threaded tubes of the two longitudinally split tubes. Carefully join the two longitudinally split threaded tubes, taking care not to cause movement of the sample, and put on the ring sleeve.
• 5.7 Smear the sample or sparingly soluble lubricating grease on the outer surface of the threaded tube and the inner surface of the sleeve, insert the threaded tube into the sleeve, and slowly rotate and push it along the axial direction.
• 5.8 Place a rubber washer under the protruding part of the threaded tube sleeve, and install the sleeve onto the platform inside the plastometer housing.
• 5.9 Open the valve of the oil supply funnel to fill the plastometer with lubricating oil. When the oil level in the housing reaches the upper end of the protruding ring of the threaded tube, close the valve of the oil supply funnel.
• 5.10 Fix the threaded tube in the housing with the nut, and pay attention to the pressure gauge when tightening the nut. If the system pressure rises (due to compression of the washer), quickly open the valve of the oil supply funnel to expel excess lubricating oil.
• 5.11 Install a protective glass cover on the upper end of the housing.
• 5.12 Place the plastometer housing into the constant-temperature bath; the liquid level of the constant-temperature bath should exceed the top of the threaded tube by 30mm.
• 5.13 According to the product standard, make the test temperature accurate to 1℃ and keep constant temperature for 20min. During the constant-temperature stage, the valve of the oil supply funnel should remain open. The interval from completion of sample stirring to the start of the test should be within 30~40min. When testing with the long threaded tube and the pressure exceeds the allowable value of the pressure gauge, the short threaded tube should be used.

8. Analysis procedure

• 6.1 Close the valve of the oil supply funnel, turn on the electric furnace switch for heating the oil reservoir, and at the same time watch the pressure gauge. When using the long threaded tube, the system pressurization rate per minute should not exceed 0.005MPa; when using the short threaded tube, it should not exceed 0.0025MPa per minute. The pressurization rate is adjusted by moving the electric furnace up and down to increase or decrease the heated surface of the oil reservoir.
• 6.2 When the system pressure reaches a certain maximum value and then begins to decrease, cut off the electric furnace power, open the valve of the oil supply funnel, slowly remove the threaded tube from the housing, and then close the valve.
• 6.3 Record the maximum pressure value, accurate to 0.001MPa.

9. Qualitative and quantitative determination and calculation formula

The ultimate strength of the sample τ (Pa) is calculated according to the following formula:

τ = P·R / (2L)

Where:

• P—— maximum pressure value, MPa;
• R—— radius of the threaded tube 0.2cm;
• L—— length of the threaded tube, cm.

Express the calculation result to four significant figures, for example: 11.77Pa, 117.7Pa, 1177Pa.

10. Precision

• Repeatability: the difference between two results obtained by the same operator in repeated determinations and their arithmetic mean shall not exceed ±10% of their arithmetic mean.
• Reproducibility: not provided in the available source.

11. Report

Take the arithmetic mean of two results from repeated determinations as the determination result.

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 reference Q&A