SH/T 0256-1992 Determination of Demulsification Time of Lubricating Oils

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 0256-92 (confirmed in 2004)
• Chinese name: Determination of Demulsification Time of Lubricating Oils
• English name: not provided in the available source
• Replacement relationship: replaces SY 2610-66(82)
• First issued: 1953 (see additional notes)

2. Scope of application and non-applicability

• Scope of application: This standard applies to turbine oils.
• Not applicable: not provided in the available source.

3. Method principle

Under the specified test conditions, the time required for the emulsion formed by the sample and steam to reach complete separation is called the demulsification time, expressed in seconds (s).

4. Reagents and materials (purity / preparation)

• 4.1 Chromic acid cleaning solution.
• 4.2 Distilled water.
• 3.2.1 Silk cloth.
• 3.2.2 Porcelain rings.
• Purity and preparation method: not provided in the available source.

5. Apparatus and equipment

• 3.1.1 Steam generator: a metal tank with a volume of 3—4L, on its cover are installed a glass tube pressure gauge with a length of 1m and an inner diameter of 5—10mm and a steam outlet pipe with an inner diameter of 5—8mm; the steam outlet pipe is bent at a right angle, and to connect the steam generator with the atmosphere, a branch pipe with a glass stopcock is installed on the steam outlet pipe. A liquid level gauge is installed beside the side wall of the steam generator near the glass tube pressure gauge. It is permissible to replace the metal tank with a glass flask with a volume of 2—3L.
• 3.1.2 Graduated cylinder: 10, 250mL.
• 3.1.3 Glass capillary: inner diameter 1.5mm±0.1mm, length 30mm±2mm.
• 3.1.4 Glass tube: inner diameter 5—8mm, bent into a L shape, two in total; the bottom end of one of the downward-bent tubes is cut at an angle of 45° (see figure).
• 3.1.5 Beaker: 2—5L.
• 3.1.6 Thermometer: 0—100℃, with a scale division of 1℃.
• 3.1.7 Conical flask: 1L, at a position below the neck 20—30mm, a downward-bent drainage glass tube with an inner diameter of 8—10mm is welded.
• 3.1.8 Electric furnace with a rheostat or transformer.
• 3.1.9 Stopwatch: division 0.1s.
• Labels in the figure: 1— glass stopcock; 2— graduated cylinder; 3— electric furnace.

6. Recommended operating conditions

• Liquid level difference between the steam generator pressure gauge and the steam generator: 300—500mm (5.4).
• Condensate outflow rate: 6mL/min±0.2mL/min, and keep it stable (5.4).
• Temperature of water in the conical flask: during each test it should not be higher than 90℃ (5.4).
• Sample holding temperature: 80—85℃ (6.1).
• Time for continued steam introduction: 10min (6.2, 6.3).
• Pressure gauge liquid level difference at the beginning and end of the test: must not be greater than 50mm (6.2).
• Separation water bath temperature: 55℃±1℃ (6.3).

7. Sampling and sample preparation

• 5.3 Pour 20mL of distilled water and 100mL of sample into a graduated cylinder of 250mL.
• Other sampling requirements: not provided in the available source.

8. Analysis procedure

• 5.1 Carefully clean the apparatus used with chromic acid cleaning solution, and install the apparatus according to the figure.
• 5.2 Fill the steam generator with distilled water to three-quarters of its height, insert the glass tube pressure gauge into the steam generator, wrap and tie the lower end of the pressure gauge with silk cloth, and add several porcelain rings to the generator to stabilize the liquid level difference; connect the L-shaped steam outlet pipe to the glass capillary with a rubber tube, and connect the other end of the capillary to a three-way tube connected to a L-shaped tube whose bottom end is cut at an angle of 45°. Insert the end of the steam outlet pipe to the bottom of the conical flask containing water up to the drainage outlet, and place a graduated cylinder of 10mL under the drainage tube of the conical flask.
• 5.3 Pour 20mL of distilled water and 100mL of sample into a graduated cylinder of 250mL.
• 5.4 Open the glass stopcock of the steam outlet pipe, heat the water in the steam generator with an electric furnace; when the water boils, close the glass stopcock, control the heating with a transformer so that the liquid level difference between the pressure gauge and the steam generator is 300—500mm. Then measure the volume of condensate flowing out from the drainage tube of the conical flask within 1min; if the measured result is within the range of 6mL/min±0.2mL/min and remains stable, record the liquid level difference between the pressure gauge and the steam generator; at this point the apparatus is considered ready and the test can be carried out. If the measured result is greater than or less than 6mL/min±0.2mL/min, adjust the heating degree of the steam generator so that the steam reaches the required rate, and record the liquid level of the pressure gauge. The temperature of the water in the conical flask during each test should not be higher than 90℃.
• 6.1 Keep the sample warm in hot water so that the sample temperature reaches 80—85℃, and insert the end of the steam exhaust glass tube into the bottom center of the graduated cylinder.
• 6.2 From the time when steam begins to emerge vigorously from the turbid liquid, let the steam continue to pass for 10min; at this time, the difference between the liquid level in the pressure gauge and the liquid level recorded at the beginning of the test must not be greater than 50mm.
• 6.3 After steam has been introduced for 10min, remove the glass tube supplying steam from the graduated cylinder, record the time, and at the same time immerse the graduated cylinder in a water bath of 55℃±1℃; when the oil layer and water layer have completely separated, record the time at which the test ends.
• 6.4 From the time when steam supply to the graduated cylinder containing the water-oil mixture is stopped until the water and oil have completely separated is the demulsification time, expressed in seconds (s).
• 6.5 Judgment of results: if between the oil layer and the water layer there is not a complete emulsion layer, the liquid is considered to be separated. The meniscus interface between the water layer and the oil layer should be clear when viewed from below; a narrow emulsion ring on the water-oil interface on the wall of the graduated cylinder is allowed. Individual bubbles at the water-oil interface, or turbidity in the water layer and oil layer, need not be noted.

9. Qualitative and quantitative determination and calculation formula

• Demulsification time: from the time when steam supply to the graduated cylinder containing the water-oil mixture is stopped until the water and oil have completely separated, expressed in seconds (s) (6.4).
• Calculation formula: not provided in the available source (no formula, only time is measured).

10. Precision

The difference between two repeated determination results shall not exceed 10% of the arithmetic mean.

11. Report

Take the arithmetic mean of two repeated determination results as the demulsification time of the sample.

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