SH/T 0661-1998 Determination of Evaporation Loss of Lubricating Greases over a Wide Temperature Range

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Card type: Test method

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

• Standard number: SH/T 0661-1998
• Chinese title: Determination of Evaporation Loss of Lubricating Greases over a Wide Temperature Range
• English title: Standard test method for evaporation loss of lubricating greases over wide-temperature range
• Adoption relationship: equivalent adoption of ASTM D2595-96 "Determination of Evaporation Loss of Lubricating Greases over a Wide Temperature Range"
• Main differences from ASTM D2595-96 (original foreword):
  1. This standard adopts the International System of Units and eliminates inch and Fahrenheit temperature expressions.
  2. Eliminates the part in the original 8.2 clause that duplicates 8.1 clause.
• Replacement relationship: not provided in the available source
• Approval/implementation: approved by China Petrochemical Corporation 1998-06-23, implemented on 1998-12-01
• Responsible committee: Research Institute of Petroleum Processing, China Petrochemical Corporation
• Drafting organization: Research Institute of Petroleum Processing, China Petrochemical Corporation
• Main drafter: Li Wenhui
• Appendix: Appendix A is an informative appendix

2. Scope of application and non-applicability

• 1.1 Applies to the determination of evaporation loss of lubricating greases within the temperature range of 93 to 316℃; this standard expands the temperature range of the GB/T 7325 method, which can only measure up to 149℃.
• 1.2 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 using this standard.
• 5.2 Can be conducted at any specified temperature between 93 and 316℃; the specific test temperature may be agreed upon with users of the test method.
• Note (5.2): This standard cannot be used at temperatures exceeding the flash point of the lubricating grease base oil.

3. Method principle

• 4 Method summary: A weighed lubricating grease sample placed in an evaporator is placed in a heater maintained at the required test temperature, hot air 22h±0.1h is passed over the surface of the lubricating grease, and the mass loss of the sample due to evaporation is determined.

4. Reagents and materials (purity / preparation)

• Not provided in the available source (this standard does not include a reagents and materials section; only air supply requirements are involved, see Section 6).

5. Apparatus and equipment

• 6.1 Evaporator assembly (Figure 1), including the following components:
  • 6.1.1 Sample cup (A)
  • 6.1.2 Cover (B)
  • 6.1.3 Lid and exhaust tube (C): these components (6.1.1 to 6.1.3) shall be of the same material as in the GB/T 7325 specification; design dimensions and tolerances are shown in Figure 2 and Figure 3.
  • 6.1.4 Gasket: shall be a heat-resistant (316℃) material; a gasket machined from 3.2mm thick polytetrafluoroethylene plate can satisfy the use.
  • 6.1.5 Thermocouple well and support: the well may be made of stainless steel tubing with an outer diameter of 3.18mm±0.025mm and fixed with a stainless steel centering support, as shown in Figure 1.
• 6.2 Air supply system: shall include a calibrated flowmeter, filtration equipment, and some accessory valves; this system shall be capable of delivering and maintaining dust-free air at a flow rate of 2.58g/min±0.02g/min (2L/min at standard temperature and standard pressure) under 15.6 to 29.4℃.
• 6.3 Heater: an aluminum block heater similar to that shown in Figure 4 can satisfy the use; more detailed description is given in Appendix A.
• 6.4 Thermometer: temperature range −5 to 400℃, shall meet the requirements of the thermometer described in GB/T 3498.
• Appendix A (informative appendix) Aluminum block heater: a suitable aluminum block heater consists of an aluminum block approximately 254mm wide, approximately 356mm long, and approximately 203mm deep; each face is well insulated; it is heated by two 650W tubular heaters and one ring heater of 500W under each of the two evaporators, as shown in Figure 4; these heaters are sufficient to heat the aluminum block for two evaporators, but if additional evaporation spaces are included, additional or larger heaters are required; these heaters shall be large enough so that the aluminum block can rise to the required test temperature within 60min after the sample is placed; the aluminum block shall be equipped with sufficiently large heaters and control instruments to maintain the required test temperature within ±1.0℃.

6. Recommended operating conditions

• Test temperature: any specified temperature between 93 and 316℃ (5.2); must not exceed the flash point of the lubricating grease base oil (5.2 Note).
• Heater temperature: required test temperature within ±1.0℃ (8.4).
• Air outlet temperature: test temperature − within 1.0℃ (8.6); during the test, the air outlet temperature shall be within ±1.0℃ of the required test temperature, and the air outlet temperature shall be the test temperature (9.3).
• Air flow rate: 2.58g/min±0.02g/min (2L/min at standard temperature and standard pressure) (6.2, 8.5, 9.3).
• Air temperature (supply air): 15.6 to 29.4℃ (6.2).
• Test duration: 22h±0.1h (4, 9.3).
• Stabilization time before test: maintain heater temperature, air outlet temperature, and air flow rate for at least 0.5h (8.7).
• Air dew point requirement (Note): air with a dew point lower than 10℃ at standard temperature and standard pressure will satisfy the requirement (5.2 Note).

7. Sampling and sample preparation

• 7 Sampling: filling a single sample cup requires approximately 20g of sample per test; sufficient sample quantity is necessary to select a representative sample for testing; inspect the sample for heterogeneous phenomena (such as oil separation, phase transition, or severe contamination); if abnormal phenomena are found, resample.
• 9.1 Sample preparation: weigh the clean sample cup and cover to the nearest 1mg; remove the cover, fill the cup with the lubricating grease sample; during filling, take care to avoid entraining air; level the grease surface with a straight-edge spatula so that it is flush with the rim of the sample cup; wipe off all grease remaining on the rim or threads of the cup with a clean cloth, screw the cover onto the sample cup without damaging the leveled grease surface; weigh the assembly and record the net weight of the lubricating grease sample to the nearest 1mg.

8. Analytical procedure

• 8 Preparation of apparatus:
  • 8.1 Thoroughly clean all components of the evaporator assembly.
  • 8.2 Refer to Figure 1; attach the lid with exhaust tube (C) to the cover (B), adjust the thermocouple well so that the bottom of the well is flush with the cover surface (as shown in the figure); insert the thermocouple into the well, adjust the thermocouple so that its tip is flush with the bottom edge of the well; press the top of the well to firmly secure the thermocouple in this position; remove the thermocouple-well assembly and detach the cover from the lid with exhaust tube.
  • 8.3 Place the lid with exhaust tube (C), thermocouple assembly, and gasket into the heater as shown in Figure 4, so that the lid is firmly fixed in position.
  • 8.4 Adjust the heater temperature so that it is within ±1.0℃ of the required test temperature; use a thermometer for observation.
  • 8.5 Adjust the air flow rate through the assembly to 2.58g/min±0.02g/min (2L/min at standard temperature and standard pressure).
  • 8.6 By adjusting the air preheater, control the air outlet temperature within test temperature − 1.0℃; measure with a thermocouple and thermometer indicator or recorder.
  • 8.7 Before the test, maintain the heater temperature, air outlet temperature, and air flow rate for at least 0.5h.
• 9 Test procedure:
  • 9.1 Weigh the clean sample cup and cover to the nearest 1mg; remove the cover, fill the cup with the lubricating grease sample; during filling, take care to avoid entraining air; level the grease surface with a straight-edge spatula so that it is flush with the rim of the sample cup; wipe off all grease remaining on the rim or threads of the cup with a clean cloth, screw the cover onto the sample cup without damaging the leveled grease surface; weigh the assembly and record the net weight of the lubricating grease sample to the nearest 1mg.
  • 9.2 Remove the lid, exhaust tube, and thermocouple assembly from the heater; screw the weighed and assembled sample cup and cover tightly onto the exhaust tube; install the entire apparatus in the heater so that the lid is firmly fixed in position; if necessary, readjust the temperature and air flow rate to meet the specified requirements.
  • 9.3 Within 22h±0.1h, maintain the air flow rate at 2.58g/min±0.02g/min (2L/min at standard temperature and standard pressure) and the air outlet temperature within ±1.0℃ of the required test temperature; the air outlet temperature shall be the test temperature.
  • 9.4 After the 22h period ends, remove the sample cup and cover from the evaporator test apparatus, cool to room temperature, and determine the net weight of the sample to the nearest 1mg.

9. Qualitative and quantitative determination and calculation formula

• 10 Calculation: the evaporation loss of the sample X% (m/m) is calculated according to formula (1):
  • X = [(S − m) / S] × 100 …………………………………（1）
  • Where: S—— mass of the sample before the test, g; m—— mass of the sample after the test, g.
  • Note: the formula symbols in the original source-text extraction contain noise (such as "S[garbled symbols]" "[unreadable value]%", etc.), the formula structure is based on the original formula (1); the symbol m appears as "。" in source-text extraction, requires confirmation against the source standard (source-text extraction).

10. Precision

• 11 Precision: judge the reliability of test results according to the following provisions (95% confidence level).
• 11.1 Repeatability: under long-term, normal, and correct operation according to this test method, the difference between two test results obtained by the same operator using the same apparatus under the specified operating conditions on the same sample shall not exceed 10% of the average of the two test results.
• 11.2 Reproducibility: under long-term, normal, and correct operation according to this test method, the difference between two single or independent test results obtained by different operators in different laboratories on the same sample shall not exceed 15% of the average of the two test results (the original source-text extraction is "[unreadable value]%", requires confirmation against the source standard (source-text extraction)).
• 11.3 Bias: because the value of evaporation loss is determined solely based on the test method, this test method cannot determine bias (the original source-text extraction is "[garbled confirmation wording]" "[garbled confirmation wording]", requires confirmation against the source standard (source-text extraction)).

11. Report

• Not provided in the available source (the source does not have a "Report" section).

12. Normative references

• GB/T 3498 Standard test method for dropping point of lubricating grease over a wide temperature range
• GB/T 7325 Standard test method for evaporation loss of lubricating greases and lubricating oils
• ASTM D2595-96 (equivalent adoption source, see Foreword)

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