SH/T 0795-2007 Determination of emulsion stability of fire-resistant fluids in category HFAE

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.

Source limitations: The source has unresolved reagent names or formulae, flask dimensions and a test-water type. The description of grade 3R is missing. Its example and reporting clauses use inconsistent R/B grade labels; these are retained below. Precision has not been established; verify the stated hardness unit before using the guidance.

Card type: Test method

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

• Standard number: SH/T 0795-2007
• Chinese title, translated: Determination of emulsion stability of fire-resistant hydraulic fluids in category HFAE
• English name: Determination of emulsion stability of fire-resistant fluids in category HFAE
• Adoption: modified adoption of ISO 20783-1:2003, Petroleum and related products — Determination of emulsion stability of fire-resistant fluids — Part one: Fluids in category HFAE (English edition), MOD.
• Replacement relationship: not found in the available source.
• Publication / implementation: published 2007-08-01; implemented 2008-01-01.
• Issuing authority: National Development and Reform Commission of the People's Republic of China.
• Responsible organization: Research Institute of Petroleum Processing, China Petroleum & Chemical Corporation.
• Drafting organization: Chongqing Yiping Lubricating Oil Branch, China Petroleum & Chemical Corporation.
• Principal drafters: Zhou Shaowei, Luo Yulan and Zheng Yuxia.

2. Scope of application and exclusions

• This standard specifies a method for testing the stability of HFAE-type emulsions of water-containing fire-resistant hydraulic fluids conforming to GB/T 7631.2.
• The emulsions are prepared using water with specified salt concentrations.
• This standard applies only to HFAE-type hydraulic fluids and cannot be used for HFA S-type hydraulic fluids (the extracted wording following HFAS is garbled; requires confirmation against the source standard).

3. Principle

The sample is stirred with standard test water to form an emulsion, then held at a specified constant temperature for a specified time. At the end of the test, the emulsion stability is observed. (Chapter 4, summary of method.)

4. Reagents and materials (purity / preparation)

• 5.1 Deionized water: meets the requirements for grade two water in GB/T 6682.
• 5.2 Tap water: water uncontaminated by particulate matter or highly soluble minerals.
• 5.3 Acetone: chemically pure. (The extracted chemical name is garbled; requires confirmation against the source standard.)
• 5.4 Isopropanol: chemically pure.
• 5.5 Calcium sulfate dihydrate (CaSO₄·2H₂O): analytical reagent grade.
• 5.6 Magnesium sulfate heptahydrate (MgSO₄·7H₂O): analytical reagent grade. (The extracted formula is "Mg50y7"; requires confirmation against the source standard.)
• 5.7 Sodium chloride (NaCl): analytical reagent grade. (The extracted grade wording is garbled; requires confirmation against the source standard.)
• 5.8 Magnesium chloride hexahydrate (MgCl₂·6H₂O): analytical reagent grade.
• 5.9 Sodium hydrogen carbonate (NaHCO₃): analytical reagent grade. (The extracted formula is "AufTCO;2"; requires confirmation against the source standard.)
• 5.10 Sodium nitrate (NaNO₃): analytical reagent grade.
• 5.11 Strong oxidizing solution: the standard strong oxidizing solution is chromic acid cleaning solution (see warning), but a chromium-free cleaning solution may be used in most cases. A laboratory cleaning agent giving the same cleaning result as the strong oxidizing solution may also be used.
• Warning (5.11): chromic acid cleaning solution is hazardous to health and toxic; its chromium compounds are considered carcinogenic. It is highly corrosive and potentially hazardous in contact with organic materials. Eye protection and protective clothing must be used when handling it. Never pipette cleaning solution by mouth. Do not discharge used solution into drains. Because it contains concentrated sulfuric acid, it must be neutralized and disposed of following the applicable laboratory procedures for toxic waste (chromium is highly hazardous to the environment). Chromium-free strong oxidizing cleaning solutions are also highly corrosive and potentially hazardous in contact with organic materials and require special handling procedures.
• Preparation of test water: see normative Annex A; compositions are given in Table A.1.

Table A.1 Composition of test water

Note: the type designation "%" in Table A.1 is garbled in the extracted source and requires confirmation against the source standard.

5. Apparatus

• 6.1 Volumetric flasks: 150 mL or 200 mL, with graduations on the neck. See Figure 1.
• 6.2 Cork stoppers: for the volumetric flasks (6.1). (The extracted stopper wording is garbled; requires confirmation against the source standard.)
• 6.3 Oven: capable of controlling and maintaining the test liquid temperature within 50 ℃±2 ℃ or 70 ℃±2 ℃.
• Figure 1 flask dimensions (extracted from the source; require confirmation against the source standard): values include ≤190, 170, φ55, 75±3, φ60 and φ83±3; the source figure annotations are incomplete.

6. Recommended operating conditions

Choose one of the following test conditions by agreement between the parties (Chapter 8):

• Test condition 1: test temperature (70±2) ℃; test duration (168±2) h.
• Test condition 2: test temperature (50±2) ℃; test duration (600±2) h.

7. Sampling and sample preparation

• 7.1 Unless otherwise specified, take samples in accordance with GB/T 4756.
• 7.2 Prepare the emulsion using one of the standard test waters in Annex A (normally the highest-hardness water stated by the product supplier to be compatible with the sample), usually at the proportion recommended by the product supplier. Stir vigorously during preparation to emulsify the sample fully and refer to the supplier's mixing instructions. Other proportions agreed by both parties may also be used.

8. Procedure

• 9.1 Choose a volumetric flask of suitable capacity (6.1) according to the expected amount of emulsion separation. A larger flask may be used if greater separation is expected. Prepare three selected flasks: soak in chromic acid cleaning solution, rinse with tap water and then deionized water, and dry in an oven. Alternatively, rinse with acetone or isopropanol and allow to dry at room temperature. Fill the flasks with the prepared emulsion (7.2) to approximately the midpoint of the graduated scale, then insert a cork stopper loosely into each flask.
• 9.2 Adjust the oven temperature to the selected test condition, place the stoppered flasks in the equilibrated oven and hold for the specified duration.
• 9.3 When the emulsion reaches the test temperature (about 30 min), remove the flasks, tighten the loosely inserted cork stoppers to prevent evaporation, and return the flasks to the constant-temperature oven. Ensure that the stoppers do not loosen during heating and that the emulsion level does not rise above the highest graduation on the flask neck.
• 9.4 At the end of the test period, remove the flasks from the oven (note: do not shake them during this operation). While the flasks and emulsions are still hot, visually assess each emulsion according to the oil-separation and emulsion-separation grades in Tables 1 and 2, and record the grade for each flask.
• 9.5 Record whether any free water is present at the bottom of each flask.

Table 1 Oil separation (A)

Note: the card gives 2 as the classification for oil adhering to the flask wall. (The extracted wording around 2 is garbled; requires confirmation against the source standard.)

Table 2 Emulsion separation (R)

9. Qualitative and quantitative determination and calculation

• 10.1 Express oil-separation results using the specified grades. At least two results should be identical. If three different grades are obtained, repeat the test. If three different grades are again obtained, report the result as 3A.
• 10.2 Express emulsion-separation results using the specified grades. At least two results should be identical. If three different grades are obtained, repeat the test. If three different grades are again obtained, report the result as 3B.
• 10.3 Express the emulsion-stability assessment using both the specified oil-separation and emulsion-separation grades.
• Example: the three individual oil-separation results are 1A, 1A and 2A, and the emulsion-separation grades are 2R, 2R and 3R; the stated stability result is 1A—2B. (This is the source example and requires confirmation against the source standard: under 10.1/10.2, the oil-separation grade is 1A and the emulsion-separation grade is 2R, but the example says "1A—2B"; source-text extraction or the original may contain an error.)
• Calculation formula: not found in the available source.

10. Precision

Precision has not yet been established for this standard. However, as guidance, in interlaboratory tests at 40 ℃ using water with hardness equivalent to 400 g/L of calcium carbonate, the combined oil and emulsion separation after standing for 25 h should be less than 0.1 mL (95% confidence level).

11. Report

The test report should include at least the following information:

• a) Reference to this standard;
• b) Complete emulsion information, including the type of water used and the percentage concentration of the sample used to prepare the emulsion;
• c) Test conditions (see Chapter 8);
• d) Stability assessment results;
• e) Whether free water is present at the bottom of the flasks;
• f) Departures from the specified procedure, whether agreed or arising for other reasons;
• g) Date of the test.

12. Referenced documents

• GB/T 4756 Petroleum liquids — Manual sampling (GB/T 4756—1998, eqv ISO 3170:1988).
• GB/T 6682 Water for analytical laboratory use — Specification and test methods (GB/T 6682—92, neq ISO 3696:1987).
• GB/T 7631.2 Classification of lubricants and related products (class L), Part 2: Family H (hydraulic systems) (GB/T 7631.2—2003, idl ISO 6743-4:1999). (The source has "idl"; requires confirmation against the source standard, possibly idt.)
• ISO 20783-1:2003 Petroleum and related products—Determination of emulsion stability of fire-resistant fluids—Part 1: Fluids in category HFAE

13. Source uncertainties requiring verification

• Items requiring confirmation against the source standard: acetone in 5.3; magnesium sulfate heptahydrate in 5.6; sodium chloride in 5.7; sodium hydrogen carbonate in 5.9; cork stoppers in 6.2; type "%" in Table A.1; the description of 3R in Table 2; the "1A—2B" example in 10.3; and "idl" for GB/T 7631.2.

14. Quick reference questions and answers