NB/SH/T 0833-2010 , HFAE, HFAS and HFC types of fire-resistant hydraulic fluids

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: NB/SH/T 0833—2010
• Chinese full name: Determination of pH value of HFAE, HFAS and HFC types of fire-resistant hydraulic fluids
• English name: Determination of pH of fire-resistant fluids within categories HFAE, HFAS and HFC
• Replacement relationship: not provided in the available source (the foreword does not mention replacement of any standard)
• Adoption relationship: modified adoption of ISO 20843:2003 (MOD), redrafted according to ISO 20843:2003
• Main differences from ISO 20843:2003: referenced standards are modified to corresponding national standards of our country; wording of repeatability and reproducibility is modified according to the practice of our country
• Publication/implementation: published on 2010-05-01, implemented on 2010-10-01
• Issuing authority: National Energy Administration
• Secretariat: National Technical Committee for Standardization of Petroleum Products and Lubricants, Subcommittee on Petroleum Fuels and Lubricants (SAC/TC 280/SC1)
• Drafting organization: Sinopec Research Institute of Petroleum Processing
• Main drafters: Guo Tao, Chen Jie, Yang Tingting

2. Scope of application and non-applicability

• Applicable to: determination of the pH value of HFAE, HFAS and HFC types of fire-resistant hydraulic fluids conforming to the classification of GB/T 7631.2 (Chapter 1).
• Not applicable: not provided in the available source.

3. Method principle

At 20℃, measure the potential difference between two electrodes immersed in the sample with a pH meter to obtain the pH value of the sample. One electrode is a glass electrode, and the other is a calomel electrode (Chapter 3). Note: An electrode assembly device may also be used.

4. Reagents and materials (purity / preparation)

• 4.1 Water: meets the requirements for grade two water in GB/T 6682.
• 4.2 Standard solutions for calibrating the pH meter
  • Preparation of buffer solution with pH value of 7.00 at 4.2.1 20℃: dissolve 3.800 g potassium dihydrogen phosphate (KH₂PO₄) and 3.415 g disodium hydrogen phosphate (Na₂HPO₄) in water, and dilute to 1000 mL. Before use, potassium dihydrogen phosphate should be dried at 110℃~120℃ for 2 h.
  • Preparation of buffer solution with pH value of 9.22 at 4.2.2 20℃: dissolve 3.80 g sodium tetraborate decahydrate (Na₂B₄O₇·10H₂O) in water, and dilute to 1000 mL.
  • Preparation of buffer solution with pH value of 11.72 at 4.2.3 20℃: dissolve 1.42 g disodium hydrogen phosphate in 100 mL carbonate-free 0.1 mol/L sodium hydroxide solution, and dilute with water to 1000 mL.
  • Note: Commercially available mixed buffer solutions may replace the buffer solutions listed in 4.2.1~4.2.3. Buffer solutions should be used within the period indicated on the buffer solution bottle (referring to commercially available mixed buffer solutions) or within three months after preparation.
• 4.3 Cleaning reagents
  • 4.3.1 Toluene: analytical reagent.
  • 4.3.2 Isopropanol: analytical reagent.

5. Instruments and equipment

• 5.1 pH meter.
• 5.2 Glass electrode and calomel electrode, or electrode assembly device.
• 5.3 Thermometer: temperature measurement range 0/100℃, graduation value 1℃.
• 5.4 Analytical balance: sensitivity 0.1 mg (the source source-text extraction is "analytical balance state blood is O: 1Mg0", requires confirmation against the source standard (source-text extraction)).

6. Recommended operating conditions

• Measurement temperature: 20℃±1℃ (7.2.1).
• Calibration temperature: 20℃ (7.1).
• Reading stabilization time: about 1 min (7.2.1).
• Test completion time limit: complete the test as far as possible within 48 h after sampling (7.2.2, the source source-text extraction is "-48r", requires confirmation against the source standard (source-text extraction)).

7. Sampling and sample preparation

• Unless otherwise specified, sampling shall be carried out in accordance with the provisions of GB/T 4756 (Chapter 6).
• The determination of the pH value should be carried out as soon as possible after sampling, and the test should be completed as far as possible within 48 h after sampling, to avoid errors caused by sample volatilization and/or changes in the pH value (7.2.2).
• Pour the sample into a glass beaker, and adjust the temperature to 20℃±1℃ (7.2.1).

8. Analytical procedure

• 7.1 pH meter calibration: at 20℃, calibrate the pH meter according to the product instructions. It is best to use the buffer solutions specified in 4.2. The pH values of the calibration buffer solutions should cover the expected pH value of the test sample (the source source-text extraction is "the pl of the calibration buffer solution! only becomes the expected pE of the test sample", requires confirmation against the source standard (source-text extraction)).
• Measurement of 7.2 pH value
  • 7.2.1 Pour the sample into a glass beaker, and adjust the temperature to 20℃±1℃. Carefully rinse the electrodes with water, immerse the electrodes in the sample, and after the pH value has stabilized for about 1 min, read the pH value. If an oil layer appears on the sample surface, avoid oil depositing on the measuring part of the glass electrode, because this will affect the contact potential and cause measurement errors.
  • 7.2.2 After the test is completed, carefully rinse the electrodes with toluene and then isopropanol in sequence.

9. Qualitative and quantitative determination and calculation formula

• Expression of results: report the pH value, accurate to 0.1 pH units (Chapter 8).
• Calculation formula: not provided in the available source.

10. Precision

Judge the reliability of test results according to the following provisions (95% confidence level).

• 9.1 Repeatability r (the source source-text extraction is "lower escape current can be at the same gold side open net one must face, only the same forest product difficult I set two discussion of the sum of the sum cannot be all over", requires confirmation against the source standard (source-text extraction))
  • HFAE, HFAS and HFC types of fire-resistant hydraulic fluids: r = 0.2 (the source source-text extraction is "7=02", requires confirmation against the source standard (source-text extraction))
• 9.2 Reproducibility R
  • HFAE and HFAS types of fire-resistant hydraulic fluids: R = 0.6
  • HFC type of fire-resistant hydraulic fluid: R = 0.3

11. Report

The test report should at least include the following contents (Chapter 10):

• a) State that this standard is implemented;
• b) The type and complete product information of the tested product; for HFAE and HFAS types of fire-resistant hydraulic fluids, include the type and concentration of water used in preparing the hydraulic fluid;
• c) Test results (see Chapter 8);
• d) Differences from the specified procedure arising from negotiated agreement or other reasons;
• e) Test date.

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—2008, ISO 3696:1987, MOD)
• GB/T 7631.2 Lubricants, industrial oils and related products (class L)—Classification—Part 2: Family H (Hydraulic systems) (GB/T 7631.2—2003, ISO 6743-4:1999, IDT) (the source source-text extraction is "day family", requires confirmation against the source standard (source-text extraction))

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 Q&A