SH/T 0209-1992 Determination of Thermal Stability of Hydraulic Oil

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 0209-92
• Chinese name: Determination of Thermal Stability of Hydraulic Oil
• English name: not provided in the available source
• Replacement relationship: replaces ZB E39 007-89
• Year confirmation: the source states "(20c year confirmation)", the specific year requires confirmation against the source standard (source-text extraction)
• Approval/implementation: approved by China Petrochemical Corporation 1992-05-20, implemented on 1992-05-20

2. Scope of application and non-applicability

• This standard specifies the method for determining the thermal stability of hydraulic oil.
• This standard applies to various hydraulic oils based on mineral oil and synthetic oil.
• Non-applicable scope: not provided in the available source.

3. Method principle

The sample is maintained at 135℃ for 168h in the presence of copper and steel rod catalysts. The thermal stability of the sample is evaluated through analysis and determination of the sample, copper rod, and steel rod before and after the thermal test.

4. Reagents and materials (purity / preparation)

4.1 Reagents

Note: In 7.2.3.3, 200g/L sodium hydroxide solution is additionally used.

4.2 Materials

• 4.2.1 Catalyst
  • 4.2.1.1 Copper rod: T2Y copper, copper content 99.90%, diameter 6.25mm, length 76.20mm.
  • 4.2.1.2 Steel rod: T10A steel, carbon content 1%, diameter 6.25mm, length 76.20mm.
  • Note: When the metal rod diameter is less than 6.20mm or cannot be polished bright, it cannot continue to be used.
• 4.2.2 Sandpaper: grit 240, 0 metallographic sandpaper.
• 4.2.3 Filter paper: rapid quantitative filter paper.
• 4.2.4 Distilled water.
• 4.2.5 Tweezers.
• 4.2.6 Writing brush.

5. Instruments and equipment

Other vessels: culture dish, watch glass, desiccator, suction filtration flask, glass microporous filter (specification not provided in the available source).

6. Recommended operating conditions

• Thermal test temperature: 135℃±1℃
• Thermal test time: 168h
• Constant temperature oven: no air blast required
• Aluminum bath placement height: about 15cm from the bottom plate of the constant temperature oven working chamber
• Thermometer position: should be as close as possible to the aluminum bath
• Steel rod alkali treatment: 200g/L sodium hydroxide solution, 82℃±1℃, maintain for 15min
• Drying oven constant weight temperature: 105～110℃
• Desiccator cooling time: 0.5h

7. Sampling and sample preparation

• 7.1.2 Measure 200mL sample with a graduated cylinder and pour into 250mL beaker.
• 6.3 Metal rod treatment:
  • 6.3.1 Place the copper rod and steel rod on a drill chuck or suitable rotator, and use sandpaper to grind off machining marks and dirt on the metal rods. Then use metallographic sandpaper for longitudinal fine grinding until the surface of the metal rods is bright, finally wipe bright with filter paper and polish with silk cloth. Note: During the wiping bright and polishing operations, never touch the metal rods directly with hands.
  • 6.3.2 Place the ground and wiped bright metal rods into a culture dish containing acetone, and scrub with absorbent cotton until the solvent used to wash the metal rods leaves no stain on the filter paper. Finally wipe dry with silk cloth, place in a desiccator, and use within 24h.
  • 6.3.3 Weigh the copper rod and steel rod before the thermal test (accurate to 0.1mg), record as m1 and m2 respectively.
• 6.4 According to GB/T 265, determine the 100℃ kinematic viscosity of the sample before the thermal test, record as v1.
• 6.5 According to GB/T 7304, determine the acid value of the sample before the thermal test, record as A1.
• 6.6 Place rapid quantitative filter paper into a clean weighing bottle, constant weight at 105～110℃, its mass recorded as m3; simultaneously constant weight the filter, its mass recorded as m4.

8. Analysis procedure

8.1 Preparation work

• 6.1 Install the electric heating automatic convection constant temperature oven in a fume hood. Place the aluminum bath at a height of about 15cm from the bottom plate of the constant temperature oven working chamber, the thermometer should be as close as possible to the aluminum bath, connect the power supply, and debug it well.
• 6.2 Soak the 250mL beaker and glass microporous filter with chromic acid cleaning solution for 4～5h, then rinse with tap water first, then suction filter and wash with distilled water. Finally rinse clean with distilled water, dry for later use.

8.2 Thermal test process (7.1)

• 7.1.1 Turn on the power of the electric heating automatic convection constant temperature oven, adjust the temperature to 135℃±1℃, no air blast required.
• 7.1.2 Measure 200mL sample with a graduated cylinder and pour into 250mL beaker, carefully place the weighed copper rod and steel rod into the beaker containing the sample, and make the two metal rods closely contact each other in parallel.
• 7.1.3 Place the beaker containing the sample and metal rods into the constant temperature aluminum bath that has reached the specified temperature, close the door of the constant temperature oven, start recording time, and continue constant temperature.
• 7.1.4 When at 135℃±1℃, constant temperature to 168h, turn off the power, transfer the sample to a fume hood, and before proceeding to the next operation, allow the sample after the thermal test to cool to room temperature.

8.3 Evaluation of copper rod and steel rod (7.2)

• 7.2.1 Take the two metal rods out of the sample, use the tip of a writing brush to sweep the loose sediment adhering to the metal rods back into the sample, and place them into two 100mL beakers respectively.
• 7.2.2 Copper rod analysis
  • 7.2.2.1 With the aid of a writing brush, wash the copper rod in the 100mL beaker with acetone to remove all oil traces on the copper rod. Then place in a desiccator, after 0.5h weigh (accurate to 0.1mg), record as m5.
  • 7.2.2.2 Compare with the copper rod appearance standard card for determination of thermal stability of hydraulic oil, evaluate the copper rod appearance by visual inspection, and record.
  • 7.2.2.3 At room temperature, carefully place the copper rod into a wide-mouth bottle containing 100g/L potassium cyanide solution until all deposits on the copper rod are removed. Take out the copper rod, immediately rinse with tap water and distilled water, then place in a culture dish containing acetone, wash two to three times with absorbent cotton, wipe dry with silk cloth, place in a desiccator, after 0.5h weigh (accurate to 0.1mg), and record as m6.
  • Warning: Potassium cyanide is highly toxic! Handle with special care, every 10mL potassium cyanide waste liquid, in alkaline conditions, can be completely decomposed with 1.8g potassium chlorate. Potassium cyanide solution can be reused three to four times. Receiving, storage, and waste liquid treatment should be strictly implemented in accordance with relevant regulations.
• 7.2.3 Steel rod analysis
  • 7.2.3.1 With the aid of a writing brush, clean the steel rod in the 100mL beaker with petroleum ether until there is no oil trace on the steel rod, then place in a desiccator, after 0.5h weigh (accurate to 0.1mg), and record as m7.
  • 7.2.3.2 Compare with the steel rod appearance standard card for determination of thermal stability of hydraulic oil, evaluate the steel rod appearance by visual inspection, and record.
  • 7.2.3.3 After visual evaluation, place into a culture dish containing 200g/L sodium hydroxide solution, cover with a watch glass, maintain at 82℃±1℃ for 15min. Take the steel rod out of the sodium hydroxide solution, immediately wipe off the softened lacquer-like deposit on the steel rod with silk cloth, then rinse with distilled water and acetone in sequence, finally wipe dry with silk cloth, and place in a desiccator. After 0.5h weigh (accurate to 0.1mg), and record as m8.

8.4 Sample evaluation (7.3)

• 7.3.1 Sediment mass determination
  • 7.3.1.1 In a fume hood, connect the M-50 type filtration movable device, the constant weight rapid quantitative filter paper, and the suction filtration flask in order to the vacuum pump, and evacuate.
  • 7.3.1.2 Pour the sample in batches into the above filter for filtration, at this time do not rinse the beaker with solvent. After all the sample has been filtered, take the sample out of the suction filtration flask, and retain for the next evaluation.
  • 7.3.1.3 Use petroleum ether to completely transfer the sediment in the thermal test cup, 100mL beaker, and writing brush to the above filter, wash the sediment with petroleum ether. If the sediment forms lumps, carefully crush, and wash again. Until the oil has been obviously washed off. Carefully take out the sediment and filter paper, and transfer them together back to the original weighing bottle.
  • 7.3.1.4 Constant weight the above weighing bottle containing sediment and filter paper at 105～110℃, its mass recorded as m9.
  • 7.3.1.5 Use a pipette to draw 7.3.1.2 of the filtered oil 25mL, pour into the constant weight glass microporous filter already mounted on the suction filtration flask, and wash the sediment clean with petroleum ether. According to 7.3.1.4 constant weight the glass microporous filter plus sediment mass, and record as m10.
• 7.3.2 Determination of sample viscosity after thermal test: According to clause 6.4, determine the viscosity of the filtered oil retained in 7.3.1.2, record as v2.
• 7.3.3 Determination of sample acid value after thermal test: According to clause 6.5, determine the acid value of the filtered oil retained in 7.3.1.2, record as A2.
• 7.3.4 After the heat test, sample analysis shall be completed within 24h; catalyst analysis shall be completed within 48h.

9. Qualitative and Quantitative and Calculation Formulas

8.1 200mL Copper Rod Mass Loss of Sample X1 (mg/200mL)

X1 = (m1 − m6) / 1000 …… (1)

Where:

• m1 — mass of copper rod before heat test, g;
• m6 — mass of copper rod after heat test, g.

8.2 200mL Steel Rod Mass Loss of Sample X2 (mg/200mL)

X2 = (m2 − m8) / 1000 …… (2)

Where:

• m2 — mass of steel rod before heat test, g;
• m8 — mass of steel rod after heat test, g.

8.3 200mL Mass of Deposit on Steel Rod of Sample Y1 (mg/200mL)

Y1 = (m7 − m8) × 1000 …… (3)

Where:

• m7 — mass of steel rod plus deposit, g;
• m8 — mass of steel rod after heat test, g.

8.4 100mL Total Sediment Mass of Sample Y2 (mg/100mL)

Y2 = [(m9 − m3)/2 + (m10 − m4) × 4 + (m5 − m6)/2] × 1000 …… (4)

Where:

• m3 — mass of weighing bottle plus filter paper, g;
• m4 — mass of glass microporous filter, g;
• m5 — mass of copper rod plus precipitate, g;
• m6 — mass of copper rod after heat test, g;
• m9 — mass of weighing bottle plus filter paper plus sediment, g;
• m10 — mass of glass microporous filter plus sediment, g.

8.5 Percentage Change in Kinematic Viscosity of Sample Before and After Heat Test Z1 (%)

Z1 = (v2 − v1) / v1 × 100 …… (5)

Where:

• v1 — kinematic viscosity of sample 100℃ before heat test, mm²/s;
• v2 — kinematic viscosity of sample 100℃ after heat test, mm²/s.

8.6 Percentage Change in Acid Number of Sample Before and After Heat Test Z2 (%)

Z2 = (A2 − A1) / A1 × 100 …… (6)

Where:

• A1 — acid number of sample before heat test, mgKOH/g;
• A2 — acid number of sample after heat test, mgKOH/g.

Qualitative Evaluation

• 7.2.2.2 Compare with the reference card for copper rod appearance in the determination of thermal stability of hydraulic oil, and evaluate the copper rod appearance visually.
• 7.2.3.2 Compare with the reference card for steel rod appearance in the determination of thermal stability of hydraulic oil, and evaluate the steel rod appearance visually.

10. Precision

• 9.1 The precision for determination of kinematic viscosity of sample 100℃ is the same as GB/T 265.
• 9.2 The precision for determination of acid number of sample is the same as GB/T 7304.
• 9.3 This standard does not specify precision.

11. Report

Take the arithmetic mean of two duplicate determination results for the sample and catalyst test items respectively as the determination result of thermal stability of hydraulic oil. These items are: the calculated values of clauses 8.1 to 8.6 and the appearance of copper and steel rods, eight items in total.

• The calculation results of clauses 8.1 to 8.4 shall be retained to one decimal place.
• The calculation results of clauses 8.5 to 8.6 shall be retained to two decimal places.

12. Referenced Documents

• GB/T 265 Petroleum products — Determination of kinematic viscosity and calculation of dynamic viscosity
• GB/T 7304 Petroleum products and lubricants — Determination of acid number (potentiometric titration method)

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