SH/T 0183-1992 Determination of explosibility of hydrocarbon fuels

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Card type: Test method

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

• Standard number: SH/T 0183-92
• Chinese name: Determination of explosibility of hydrocarbon fuels
• English name: not provided in the available source
• Replacement relationship: replaces ZB E31 013-88
• Other: approved by China Petrochemical Corporation 1992-05-20, implemented on 1992-05-20; (source-text extraction shows "(2 month "Zhou) year confirmation)", the year number requires confirmation against the source standard (source-text extraction))
• Additional notes: This standard was first published in 1981; it refers to and adopts the explosibility test method in clause 4.9 of Japanese Industrial Standard JIS K 2276-1983 "Test Methods for Aviation Fuels"

2. Scope of application and non-applicability

• Scope of application: This standard applies to jet fuel, diesel and boiler fuel, etc.
• Not applicable: not provided in the available source

3. Method principle

Under specified conditions, use a combustible gas explosimeter to evaluate the explosibility of the mixture of combustible vapor released by the fuel and air. The explosimeter is calibrated with 50% of the lower explosive concentration limit volume percentage [%(V/V)] of a known hydrocarbon gas (propane, etc.), and 50% of the lower explosive concentration limit volume percentage [%(V/V)] of a known hydrocarbon gas is taken as the evaluation limit.

4. Reagents and materials (purity / preparation)

• 5.1 Hydrocarbon gas: propane [lower explosive concentration limit 2.1%(V/V)] or butane, isobutane [lower explosive concentration limit 1.8%(V/V)], purity 95% or above.
• 5.2 Anhydrous calcium chloride: chemically pure.
• 4.2 Material: compressed air.
• Appendix A Reagent: n-pentane: chemically pure.
• Preparation of calibration gas (6.1.1): when the volume of the hydrocarbon gas and air mixture is 2L, the lower explosive concentration limit [%(V/V)] is 50% amount of hydrocarbon gas (V) calculated according to formula (1): V = 10 / Ex (where Ex— lower explosive concentration limit of hydrocarbon gas, %(V/V)). The original formula source-text extraction is "V = IO E,", requires confirmation against the source standard (source-text extraction).

5. Instruments and equipment

• 4.1.1 HBB-1S combustible gas explosimeter (or other brands of the same type of instrument).
• 4.1.2 Drying tube: volume about 15mL, filled with anhydrous calcium chloride.
• 4.1.3 Oil-gas separator: volume about 15mL.
• 4.1.4 Graduated cylinder: 100mL.
• 4.1.5 Funnel.
• 4.1.6 Water tank: volume sufficient to accommodate a 2L volumetric flask and a 100mL graduated cylinder.
• 4.1.7 Constant-temperature water bath: volume sufficient to accommodate a 1L wide-mouth bottle. Water temperature controlled at 65-70℃.
• 4.1.8 Volumetric flask: 2L, with a two-hole rubber stopper, one hole inserted with a water delivery tube, the lower end of the tube located near the graduation line of the volumetric flask; the other hole inserted with a gas discharge tube, the lower end of the tube inserted below the lower edge of the rubber stopper, the upper end of the tube connected to a short rubber tube, clamped with a clip.
• 4.1.9 Sample bottle: capacity 1L wide-mouth bottle, with a three-hole rubber stopper, respectively inserted with a warm water inlet tube, a gas discharge tube and a thermometer.
  • 4.1.9.1 Warm water inlet tube: the lower end of the tube is about 15mm from the bottom of the bottle, the upper end connected to a short rubber tube, clamped with a clip.
  • 4.1.9.2 Gas discharge tube: copper tube with outer diameter about 5mm, the lower end of the copper tube is closed, and a small hole with diameter about 3mm is opened at about 15mm from the bottom of the lower end.
  • 4.1.9.3 Thermometer: 0—100℃ (source-text extraction is "0[unreadable separator]look", requires confirmation against the source standard (source-text extraction)), graduation value 1℃, the thermometer is located at the center of the sample bottle, and its mercury bulb is located at half the height of the oil sample liquid surface.
• 4.1.10 Warm water bottle: capacity 1L wide-mouth bottle, with a two-hole rubber stopper, one hole inserted with a gas inlet tube, the lower end of the tube about 25mm from the lower edge of the rubber stopper; the other hole inserted with a warm water discharge tube, its lower end about 15mm from the bottom of the bottle.
• Note: Except that the gas discharge tube of the sample bottle is a copper tube, all others are glass tubes with outer diameter about 5mm.
• Appendix A Instruments:
  • A1.1 Microsyringe: 100μL (source-text extraction is "100VLa", requires confirmation against the source standard (source-text extraction)).
  • A1.2 Volumetric flask: 2L, with a three-hole rubber stopper, the middle hole inserted with a thermometer, the mercury bulb of the thermometer located at the center of the volumetric flask, the other two holes sized to allow insertion of glass tubes with outer diameter 5mm, one of which is the warm water inlet tube, the lower end of the tube near the graduation line of the volumetric flask; the other is the gas discharge tube, inserted below the lower edge of the rubber stopper. The upper ends of the two tubes are respectively connected to short rubber tubes, clamped with clips.
  • A1.3 Thermometer: 0—50℃, graduation value 0.1℃.

6. Recommended operating conditions

• Explosimeter calibration: calibrate with 50% of the lower explosive concentration limit volume percentage [%(V/V)] of a known hydrocarbon gas; the evaluation limit is taken as 50% of the lower explosive concentration limit volume percentage [%(V/V)] of a known hydrocarbon gas.
• Sample heating conditions: place the sample bottle in a 65-70℃ hot water bath so that the liquid surface of the sample bottle is below the liquid surface of the hot water bath, and continuously shake the sample bottle; when the test temperature reaches 52℃±1℃, remove the sample bottle and shake vigorously for 5min; during shaking, frequently immerse the sample bottle in the hot water bath so that the sample temperature is always maintained at 52℃±1℃.
• Warm water bottle conditions: inject about 500mL of 52℃±1℃ warm water into the warm water bottle.
• Compressed air conditions: input compressed air pre-adjusted to a certain pressure into the warm water bottle, so that the water in the warm water bottle flows out uniformly about 500mL within 20s.
• Appendix A n-pentane calibration conditions: evacuate the volumetric flask to about 40-53kPa; use a microsyringe to take 62μL n-pentane (source-text extraction is "621 .L", requires confirmation against the source standard (source-text extraction)); place the volumetric flask in a hot water bath (water temperature about 45-50℃), heat to 40℃±1℃; keep the temperature inside the flask at 40℃±1℃; add about 500mL 40℃±1℃ warm water into the warm water bottle.

7. Sampling and sample preparation

• Sampling according to GB/T 4756, add about 500mL of the sample to be tested into the sample bottle, stopper with the prepared rubber stopper, lift the gas discharge tube upward so that the rubber stopper blocks the vent hole.
• Sample heating and shaking: place the sample bottle in a 65-70℃ hot water bath so that the liquid surface of the sample bottle is below the liquid surface of the hot water bath, and continuously shake the sample bottle. When the test temperature reaches 52℃±1℃, remove the sample bottle and shake vigorously for 5min. During shaking, frequently immerse the sample bottle in the hot water bath so that the sample temperature is always maintained at 52℃±1℃.

8. Analytical procedure

8.1 Explosimeter calibration

• 6.1.1 Preparation of hydrocarbon gas with lower explosive concentration limit volume percentage [%(V/V)] of 50%:
  • 6.1.1.1 When the volume of the hydrocarbon gas and air mixture is 2L, the lower explosive concentration limit [%(V/V)] is 50% amount of hydrocarbon gas (V) calculated according to formula (1): V = 10 / Ex (where Ex— lower explosive concentration limit of hydrocarbon gas, %(V/V)). The original formula source-text extraction is "V = IO E,", requires confirmation against the source standard (source-text extraction).
  • 6.1.1.2 Pour about 500mL water into a 2L volumetric flask, then invert the volumetric flask in a water tank so that the graduation line of the volumetric flask coincides with the water surface in the tank. Fix the volumetric flask with a stand.
  • 6.1.1.3 Fill a 100mL graduated cylinder with water and invert it in the water tank so that the graduation of the graduated cylinder equal to the calculated volume of hydrocarbon gas coincides with the liquid surface of the water tank, and fix the graduated cylinder vertically with a stand. Introduce hydrocarbon gas into the graduated cylinder to displace the water inside the graduated cylinder until it equals the calculated volume of hydrocarbon gas (mL).
  • 6.1.1.4 Place a funnel on the mouth of the volumetric flask, align the graduated cylinder with the flared mouth of the funnel, and introduce all the hydrocarbon gas in the graduated cylinder into the volumetric flask.
  • 6.1.1.5 Introduce air into the volumetric flask until the liquid surface (water) inside the volumetric flask is at the graduation line (inside and outside).
  • 6.1.1.6 Stopper the volumetric flask tightly with the prepared rubber stopper and take it out. Repeatedly invert the volumetric flask to ensure the gas is uniformly mixed.
• 6.1.2 Determination of hydrocarbon gas with lower explosive concentration limit [%(V/V)] of 50%:
  • 6.1.2.1 Add about 500mL tap water into the warm water bottle, and stopper with the prepared rubber stopper.
  • 6.1.2.2 Connect the gas discharge tube of the volumetric flask to the drying tube, connect the other end of the drying tube to the oil-gas separator, and then connect the oil-gas separator to the explosimeter. Connect the water delivery tube of the volumetric flask to the drain tube of the warm water bottle.
  • 6.1.2.3 Set the explosimeter switch to the "on" position, and quickly adjust the current and zero point.
  • 6.1.2.4 Input compressed air pre-adjusted to a certain pressure into the warm water bottle, so that the water in the warm water bottle flows out uniformly about 500mL within 20s. First open the clip of the gas discharge tube of the volumetric flask, then open the clip of the water delivery tube of the volumetric flask. Observe the explosimeter reading. When the explosimeter reading is constant, record the reading.
• 6.2 Cleaning the system: after each calibration, the volumetric flask must be filled with water for cleaning. Purge the entire system with compressed air until the explosimeter pointer basically returns to zero.

8.2 Sample determination

• 7.1.1 Sampling according to GB/T 4756, add about 500mL of the sample to be tested into the sample bottle, stopper with the prepared rubber stopper, lift the gas discharge tube upward so that the rubber stopper blocks the vent hole.
• 7.1.2 Place the sample bottle in a 65-70℃ hot water bath so that the liquid surface of the sample bottle is below the liquid surface of the hot water bath, and continuously shake the sample bottle. When the test temperature reaches 52℃±1℃, remove the sample bottle and shake vigorously for 5min. During shaking, frequently immerse the sample bottle in the hot water bath so that the sample temperature is always maintained at 52℃±1℃.
• 7.1.3 Inject about 500mL of 52℃±1℃ warm water into the warm water bottle, stopper with the prepared rubber stopper, and quickly connect the sample bottle and the warm water bottle as shown in the figure below.
• 7.1.4 Set the explosimeter switch to the "on" position, and quickly adjust the current and zero point.
• 7.1.5 Input compressed air pre-adjusted to a certain pressure into the warm water bottle, so that the water in the warm water bottle flows out uniformly about 500mL within 20s. First press down the gas discharge copper tube so that the vent hole is in the oil vapor, then open the clip of the warm water inlet tube of the sample bottle. Observe the explosimeter reading. When the explosimeter reading is constant, record the reading.
• 7.2 Cleaning the system: after each test, the sample bottle must be filled with water for cleaning. Purge the entire system with compressed air until the explosimeter pointer basically returns to zero.

8.3 Appendix A Calibration of explosimeter with n-pentane (supplementary element)

In the absence of propane, n-pentane may be used instead.

• A3.1 Preparation of n-pentane with lower explosive concentration limit [%(V/V)] of 50%:
  • A3.1.1 Stopper the volumetric flask with the prepared rubber stopper, and use a vacuum pump to evacuate the volumetric flask to a certain degree of vacuum (about 40-53kPa).
  • A3.1.2 Using a microsyringe, take 62μL n-pentane and inject it into the volumetric flask through the rubber stopper of the volumetric flask. The original text is "621 .L", requires confirmation against the source standard (source-text extraction).
  • A3.1.3 Invert the volumetric flask, draw in a certain amount of water through the volumetric flask delivery tube so that the volumetric flask is inverted and its water surface is exactly at the graduation line.
  • A3.1.4 Place the volumetric flask in a hot water bath (water temperature about 45-50℃), and heat until 40℃±1℃. Remove the volumetric flask, open the clamp of the volumetric flask delivery tube (or gas discharge tube) several times in portions, draw in air, and finally bring the pressure inside the flask into equilibrium with the external pressure. Note that the temperature inside the flask should be maintained at 40℃±1℃.
  • A3.1.5 Repeatedly invert the volumetric flask to ensure the gas is uniformly mixed.
• A3.2 Determination of the lower explosive concentration limit [%(V/V)] of n-pentane as 50%: add about 500mL 40℃±1℃ warm water into the warm water bottle, and stopper it with the prepared rubber stopper. The other operating steps are the same as 6.1.2.2, 6.1.2.3 and 6.1.2.4 of this standard.

9. Qualitative and Quantitative and Calculation Formulas

• The explosive test value of the sample vapor P (equivalent to the percentage of the lower explosive concentration limit of known hydrocarbon gases) [%(V/V)] is calculated according to formula (2):
  • P = 50 × V1 / V2
  • Where: V1— the lower explosive concentration limit of hydrocarbon gas [%(V/V)] is the instrument indication value of 50%; V2— is the indication value of the explosimeter.
  • The original formula (2)source-text extraction is "_ 50 V, [garbled formula]", requires confirmation against the source standard (source-text extraction).
• Calculation formula for preparing calibration gas (1): V = 10 / Ex; where Ex— lower explosive concentration limit of hydrocarbon gas, %(V/V). The original text source-text extraction is "V = IO E,", requires confirmation against the source standard (source-text extraction).

10. Precision

Repeatability: The difference between two results of repeated determination by the same operator shall not be greater than the following values.

• Explosive test value range 0-20 %(V/V): repeatability 4 %(V/V)
• Explosive test value range >20-40 %(V/V): repeatability 8 %(V/V) (source-text extraction is "S", requires confirmation against the source standard (source-text extraction))
• Explosive test value range >40 %(V/V): repeatability 12 %(V/V)

11. Report

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

12. Referenced Documents

• GB/T 4756 Petroleum liquids—Manual sampling

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