HG/T 3665-2000 Pure rubber hose and rubber hose for transporting oxygenated fuel in internal combustion engine fuel system
Some standard content:
Registration No.: 7265--2000
HG/T 3665--2000
This standard is equivalent to the international standard ISO4639-2:1995 "Pure rubber hose and rubber hose for internal combustion engine fuel system Part 2:
Oxygenated fuel".
The series of standards for "Pure rubber hose and rubber hose for internal combustion engine fuel system" includes the following three standards: HG/T3042--1989 "Pure rubber hose and rubber hose for conveying conventional liquid fuel in internal combustion engine fuel system" eqvISO4639-1:1987)
HG/T3665-2000 "Pure rubber hose and rubber hose for conveying oxygenated fuel in internal combustion engine fuel system" (idtISO4639-2:1995) HG/T3666-2000 "Pure rubber hose and rubber hose for conveying oxidized fuel in internal combustion engine fuel system" (idtISO4639-3:1995) Appendix A, Appendix B, Appendix C and Appendix D of this standard are the appendices of the standard. Appendix E is a prompt appendix. This standard was proposed by the Technical Supervision Department of the former Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Hose Sub-Technical Committee of the National Technical Committee for Standardization of Rubber and Rubber Products. The responsible drafting unit of this standard: Shenyang Rubber Research and Design Institute of the Ministry of Chemical Industry. The main drafters of this standard are Li Chunming and Cheng Hongyu. 378
HG/T 3665—2000
ISO Foreword
The International Organization for Standardization (ISO) is a worldwide federation of national standards bodies (ISO member bodies). The work of formulating international standards is usually carried out by ISO technical committees. Any member body interested in a project for which a technical committee has been established has the right to participate in the committee. International organizations, both governmental and non-governmental, that have ties to ISO may also participate in this work. ISO works closely with the International Electrotechnical Commission (IEC) in all aspects of electrotechnical standardization. Draft international standards adopted by the technical committee are sent to member bodies for voting. When published as an international standard, at least 75% of the voting member bodies are required to vote in favor
International standard ISO4639-2 was developed by ISO/TC45 Rubber and Rubber Products Technical Committee SC1 Hose (Rubber and Plastics) Sub-Technical Committee.
The general title of ISO 4639 is "Specification for pure rubber tubing and hoses for fuel circuits for internal combustion engines using oxygenated fuels" and it consists of the following three parts: Part 1: Conventional liquid fuels
Part 2: Oxygenated fuels
Part 3: Oxygenated fuels
Appendices A, B, C and D are the appendices that constitute the standard for this part of ISO 4639. 379
1 Scope
Chemical Industry Standard of the People's Republic of China
Rubber tubing and hoses for fuel circuits for internal Combustion engines using oxygenated fuelsHG/T 3665—2000
idt ISO 4639-2:1995
This standard specifies the requirements for pure rubber tubing and hoses for use in fuel systems using liquid fuels to which oxygenates such as ethanol have been added (excluding equipment for liquid fuel dispensing). These hoses and pure rubber hoses are used in conventional carburetor systems where the fuel is unlikely to be oxidized and have moderate resistance to oxidized (acidic) fuels. 2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. The versions shown are valid when this standard is published. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T528-1998 Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber (eqvISO37:1994) GB/T1690-1992 Test method for resistance of vulcanized rubber to liquids (neqISO1817:1985) GB1800.2-1998 Basis of limits and fits Part 2: Basic provisions for tolerances, deviations and fits (eqvISO286-1:1988)
GB2941-1991 Standard temperature, humidity and time for environmental conditioning and testing of rubber specimens (eqvISO471:1983) GB/T3512-1983 (1989) Test method for hot air aging of rubber (neqISO188:1976) GB/T3672-1992 Dimensional tolerances for molded, extruded and calendered solid rubber products (eqvISO3302:1988) GB/T 5563--1994
Hydraulic test methods for rubber, plastic hoses and hose assemblies GB/T5564--1994 Low-temperature flexure test for rubber and plastic hoses (neqISO4672:1988) GB/T 5565-1994
Bending test for rubber or plastic hoses and pure rubber hoses (neqISO1747:1973) GB/T55671994 Determination of vacuum properties of rubber, plastic hoses and hose assemblies GB/T 6031-1998
GB/T 7759-1996
Determination of hardness of vulcanized rubber or thermoplastic rubber (10~100IRHD) (idtISO48:1994) Determination of compression set of vulcanized rubber and thermoplastic rubber at room temperature, high temperature and low temperature (eqvISO815:1991)
GB/T 9573--1988
3Methods for measuring dimensions of rubber, plastic hoses and hose assemblies (idtISO4671:1984)Analysis method for multi-peak curves of tear strength and adhesion strength of rubber and plastics (eqvISO6133:1981)GB/T12833-1991
GB/T14905-1994
Determination of adhesion strength between layers of rubber and plastic hoses (eqvISO8033:1991)HG/T2869-1997Ozone resistance of rubber and plastic hoses under static conditions Performance evaluation (idtISO7326:1991)ISO8308:1993 Rubber and plastic hoses and non-reinforced hoses Liquid wall permeability determination 3 Types of pure hoses and hoses
Pure hoses and hoses are divided into the following three different types: Approved by the State Administration of Petroleum and Chemical Industry on May 23, 2000 380
Implementation on December 1, 2000
HG/T3665--2000
Type 1: pure hose, maximum working pressure is 0.12MPa; Type 2: hose, working pressure is 0~0.12MPa; Type 3: hose, working pressure is 0~0.3MPa. In addition, the above three types of 1, 2 and 3 can be further divided into two levels: Class A: working at an ambient temperature of up to 120C; Class B: working at an ambient temperature of up to 140C. Class B pure hoses can be provided with an outer covering.
Inner wall of pure rubber hose and hose
The inner wall of all pure rubber hose and hose should be clean and should not have any impurities during visual inspection. 5 Dimensions
5.1 Pure rubber hose
When measured according to the method specified in GB/T9573, the inner diameter and wall thickness should comply with the provisions of Table 1. The tolerance should be selected according to the corresponding category specified in GB/T3672: M3 for molded tubes and E2 for extruded tubes. Note: For information, the connectors matching the pure rubber hose should have the following diameters: 4mm, 4.5mm, 6mm or 6.35mm.8mm, 10mm.12mm and 14 mm.
Inner diameter and wall thickness of pure rubber hose
Nominal inner diameter
Nominal wall thickness
5.2 Hose
When measured according to the method specified in GB/T9573, the size, tolerance and concentricity of the hose shall conform to the provisions of Table 2 and Table 3. Table 2 Hose size
Nominal inner diameter
3.5 or less (including (3.5)
3.5 or more
6 Physical tests and specifications
6.1 Requirements for materials
HG/T 3665-2000
Table 3 Hose concentricity
Maximum concentricity error
Inner diameter to outer diameter
Whenever possible, the test specimens cut from the product should be used for testing. If this is not possible, the specimens should be cut from standard test films with the same degree of vulcanization as the product. Standard specimens should be used for the determination of compression set. 6.1.1 Hardness
When measured according to the procedure specified in GB/T6031 (micro test), the hardness shall comply with the provisions of Table 4. 6.1.2 Tensile strength and elongation at break
When measured using No. 2 dumbbell specimens according to the procedure specified in GB/T528, the tensile strength and elongation at break shall conform to the requirements of Table 4.
Table 4 Requirements for materials
Chapter number
6. 1. 6. 1
Nominal hardness
Tensile strength, minimum
Elongation at break, minimum
Accelerated aging
Hardness change
Maximum increase!
Maximum reduction
Tensile strength decreases, maximum
Elongation at break decreases, maximum
Ozone resistance
Compression set, maximum (100±1)℃X(72.-2)h
Hydrocarbon resistance
Hardness decreases, maximum
Tensile strength decreases, maximum
Elongation at break decreases, maximum
Volume expansion, maximum
Oxygenated fuel resistance
Hardness decreases, maximum
Tensile strength decreases, maximum
Elongation at break decreases, maximum
Volume expansion, maximum
Oxidized fuel resistance
|Hardness decreases, maximum
Tensile strength decreases, maximum
Elongation at break decreases, maximum
Volume expansion, maximum
Pure rubber hose
Requirements for Grade A and Grade B
Outer covering,
If required
Hose lining [
Hose outer covering
Magnify 2 times to observe no cracks
Chapter number
No. 3 oil resistance
Tensile strength decreases, maximum
Elongation at break decreases, maximum
Volume change
Increases, maximum
Decreases, maximum
1) The maximum absolute value should not exceed 90IRHD. 6.1.3 Changes in properties after accelerated aging
HG/T 3665—2000
Table 4 (end)
Pure hose
Requirements for Grade A and Grade B
Outer covering,
If required
Hose inner lining
Hose outer covering
Accelerated aging test shall be carried out in accordance with the provisions of GB/T3512 in a ventilated drying oven, using the specimens specified in 6.1.1 and 6.1.2, under the following conditions:
-A grade pure hose, hose outer covering and hose inner lining, and B grade hose inner lining: (120±2)CX(72_,)hGrade B pure hose, pure hose outer covering and hose outer covering: (140±2)C×(72-2)h. Changes in hardness, tensile strength and elongation at break shall comply with the provisions of Table 4. 6.1.4 Ozone resistance
After accelerated aging according to the provisions of 6.1.3, the test shall be carried out according to the corresponding method specified in HG/T2869. When inspected with a double magnifying glass under the following conditions, the sample shall not show cracking (see Table 4). Ozone partial pressure: (50±3) mPa;
Cycle: (72.2) h;
Elongation:
20% for hose outer coating and inner lining;
50% for pure rubber hose (including lining);
Temperature: (40±2) C.
6.1.5 Compression set
When measured under the conditions specified in Table 4 using a large specimen (type A) as specified in GB/T7759, the compression set shall comply with the provisions of Table 4.
6.1.6 Fuel resistance
Warning: Fuel is extremely dangerous at high temperatures. The test should be carried out in an explosion-proof cabinet under reflux. 6.1.6.1 Hydrocarbon resistance (Liquid C specified in GB/T1690) This requirement is only applicable to the inner lining of pure rubber hoses and hoses. After immersion in Liquid C at (60±1)°C for (72-2)h, the hardness (6.1.1), tensile strength (6.1.2), elongation at break (6.1.2) and any change in volume shall comply with the provisions of Table 4. 6.1.6.2 Oxygenated fuel resistance
This requirement is only applicable to the inner lining of pure rubber hoses and hoses. After being immersed in a mixture of 85% by volume of Liquid C (GB/T1690) and 15% by volume of methanol at (60±1)°C for (729) hours, the hardness (6.1.1), tensile strength (6.1.2), elongation at break (6.1.2) and any change in volume shall comply with the requirements of Table 4.
6.1.6.3 Resistance to oxidation fuel
This requirement applies only to pure rubber hoses and hose liners. After being immersed in the test liquid specified in Appendix A at (60 ± 1) °C for (140 ± 2) h, the hardness (6.1.1), tensile strength (6.1.2), elongation at break (6.1.2) and any change in volume shall comply with the provisions of Table 4. 6.1.7 No. 3 oil resistance
This requirement is only applicable to the outer covering of dry pure rubber hoses and hoses. After the A-grade product specimens are immersed in No. 3 oil at (120 ± 2) °C and the B-grade product specimens are immersed in No. 3 oil at (140 ± 2) °C for (72.9) h, the tensile strength (6.1.2), elongation at break (6.1.2) and any change in volume shall comply with the provisions of Table 4.
6.2 Requirements for finished products
6.2.1 Leakage test
This requirement applies only to pure rubber hoses.
Put the pure rubber hose on the polished end of a metal tube. The machining tolerance of the metal tube is defined as H14 according to GB1800.2, and its diameter should be equal to the corresponding value given in the note of 5.1. The distance that the pure rubber hose is pushed inward along the metal tube should be 3 times the nominal inner diameter of the pure rubber hose. The other end of the metal tube should be closed, and the other end of the pure rubber hose should be connected to the air pressure source. Then, the assembly is subjected to an internal pressure of 0.12MPa and maintained for 2min. The medium is liquid C. No leakage should occur during the test (see Table 5).
6.2.2 Tensile test
This requirement applies only to pure rubber hoses.
Put a section of pure rubber hose on one end of the metal pipe according to the method described in 6.2.1, then hang the assembly vertically along the metal pipe, and make the pure rubber hose bear a 10N load applied to the other end plugged with a plug. The pure rubber hose should not break or slip off (see Table 5). 6.2.3 Minimum bursting pressure
The minimum bursting pressure measured according to the procedure specified in GB/T5563 shall comply with the provisions of Table 5. 6.2.4 Adhesion strength
This requirement is only applicable to hoses.
The adhesion strength between the outer covering layer and the reinforcement layer and between the lining layer and the reinforcement layer measured according to the corresponding method specified in GB/T14905 shall comply with the provisions of Table 5.
Table 5 Requirements for finished products
Chapter number
Leak test
Tensile test
Minimum burst pressure
Adhesion strength (outer layer and inner lining layer to reinforcement layer) Peel force, minimum
Low temperature flexibility
Cleanliness
Insoluble impurities, maximum
Solids soluble in fuel, maximum
Extractable wax products, maximum
Permeability of liquid C, maximum
Tear resistance, minimum
Suction flattening resistance
Bending resistance
Deformation coefficient D'/D
Pure rubber hose
No leakage
No breakageNo slippage
2By magnification, no signs of cracking
The ball should be able to pass through the entire hose
Chapter number
6.2.12 and
Long-term resistance to oxygenated fuel
Suction flattening resistance
Bending resistance
Deformation coefficient D /D, minimum
Ozone resistance
Minimum burst pressure
HG/T 3665--2000
Table 5 (Complete)
Adhesion strength (outer layer and inner layer to reinforcing layer) Peel force·minimum
Low temperature flexibility
Accelerated aging
6.2.5 Low temperature flexibility
This test shall be carried out under the following conditions according to method B specified in GB/T5564. Empty pure rubber hose or hose: (-25±2)C×(24-2)h. Pure rubber hose or hose filled with liquid C: (-40±2)C×(72-2)h. Pure rubber hose
The ball should be able to pass through the entire hose
2 times magnification, no signs of cracking
2 times magnification, no signs of cracking
2 times magnification.Internal and external cracking or deterioration
The time interval between filling the pure rubber hose or hose with liquid and the start of freezing should not be more than 30 minutes. The bending radius of the hose should be 12 times its nominal internal diameter, and the bending radius of the pure rubber hose should be 25 times its nominal internal diameter. After flexing, the pure rubber hose or hose should not show signs of cracking when examined with a 2x magnifying glass (see Table 5). Note: The "empty" test widely used in industry is only used for arbitration tests. 6.2.6 Cleanliness
The impurity content measured in Appendix B shall comply with the provisions of Table 5. 6.2.7 Determination of wax products extracted with liquid C The content of extractable wax products measured in Appendix B shall comply with the provisions of Table 5. 6.2.8 Penetration of liquid C
The penetration value of liquid C measured by method A specified in IS () 8308 (see Appendix E) at (40 ± 1) C for (100 ± 2) h shall comply with the provisions of Table 5.
6.2.9 Tear resistance
This requirement is only applicable to pure rubber hoses.
The tear resistance measured in Appendix C shall comply with the provisions of Table 5. 6.2.10 Suction resistance
This test shall be carried out only on straight hoses according to Method A specified in GB/T5567 under the following conditions: Vacuum: 80kPa;
Cycle: 15~60s;
Ball diameter: nominal inner diameter × 0.8.
The ball shall be able to pass through the entire hose (see Table 5). 6.2.11 Bending resistance
This requirement is only applicable to straight pure rubber hoses and hoses with an inner diameter not exceeding 16mm. The test shall be carried out in accordance with GB/T5565, and the diameter of the coil used is as follows: 140mm for pure rubber hoses and hoses with a diameter of 7~~11mm (including 11mm). For pure rubber hoses and flexible hoses with a diameter of 12 to 16 mm (including 16 mm), it is 220 mm. The deformation coefficient D'/D shall comply with the values specified in Table 5. 385
6.2.12 Long-term resistance to oxygenated fuel
HG/T 3665-—2000
Pure rubber hose or flexible hose samples shall be subjected to a long-term cycle test of oxygenated fuel for 1000 h at (60 ± 1)°C in accordance with the provisions of Appendix D. The first sample shall then be subjected to the tests specified in 6.2.12.1 to 6.2.12.4. The second sample shall be subjected to the test specified in 6.2.12.5. The third sample shall be subjected to the test specified in 6.2.12.6. 6.2.12.1 Resistance to flattening: When tested in accordance with the method specified in 6.2.10, the ball shall pass through the entire hose (see Table 5). 6.2.12.2 Bending resistance: The deformation coefficient D'/D measured in accordance with 6.2.11 shall comply with the value specified in Table 5. 6.2.12.3 Ozone resistance: Under the following conditions, the test shall be carried out in accordance with method 1 specified in HG/T2869. When inspected with a 2x magnifying glass, the specimen shall not show signs of cracking (see Table 5).
Ozone partial pressure: (50±3)mPa.
Cycle: (72.9)h.
Elongation: 20% for hose outer covering, inner lining and lining; 50% for pure rubber hose (including lining). Temperature: (40±2)℃.
6.2.12.4 Minimum bursting pressure: The minimum bursting pressure measured in accordance with 6.2.3 shall comply with the provisions of Table 5. 6.2.12.5 Adhesion strength: The adhesion strength between the outer cover and the inner lining and the reinforcement layer measured in accordance with 6.2.4 using the second specimen specified in 6.2.12 shall comply with the requirements of Table 5. 6.2.12.6 Low temperature flexural properties: According to the requirements of 6.2.5, the third specimen specified in 6.2.12 shall be tested. When inspected under a 2x magnifying glass, no cracking shall be observed (see Table 5). 6.2.13 Changes in properties after accelerated aging
Bend a pure rubber hose or hose specimen of appropriate length into a ring with two ends connected and approximately 250 mm in diameter, and place it in a ventilated oven at (150 ± 3)°C for aging for (72.2) h. At the end of the aging cycle, straighten the specimen for 4 to 8 seconds. After straightening, inspect it under a 2x magnifying glass. There shall be no signs of cracking or erosion inside or outside the specimen (see Table 5). 7 Marking
Unless the components are too small to be marked, pure rubber hoses and flexible pipes shall be printed with a mark containing the following information: a) fuel;
b) manufacturer's name or trademark;
c) number of this standard;
d) type and grade;
e) year and month of manufacture,
f) inside diameter.
A1 Scope
HG/T3665—2000
Appendix A
(Standard Appendix)
Preparation of Oxidized Fuel Test Liquid
This appendix specifies the method for preparing oxidized ("acidic") gasoline test solutions, which are used to determine their effects on elastomers, plastics and metal materials and components. This annex applies to solutions of PN 90 prepared from tert-butyl hydroperoxide (70% aqueous solution), soluble copper ions (0.01 mg/dm2) and a base fuel containing 80% by volume of Liquid C, 15% methanol and 5% 2-methylpropan-2-ol (tert-butyl alcohol). Other base fuels and peroxide numbers may be used when required by engineering drawings or specifications, but it should be noted that some base fuels may produce aqueous phase separation of the peroxide solution. This annex also describes the determination of the fuel peroxide number. A2 Reagents
Unless otherwise specified, only analytical reagents and distilled water or water of equal purity shall be used in the analysis. A2.1 Tert-butyl hydroperoxide: 70% aqueous solution, p = 0.935 g/cm2. A2.2 Copper ion concentrate: A solution of copper cyclohexane containing 6% to 12% copper by mass in a suitable hydrocarbon as solvent. A2.3 2,2,4-Trimethylpentane (isooctane). Warning: Low flash point.
A2.4 Toluene.
Warning: Low flash point.
A2.5 Methanol.
Warning: Low flash point.
A2.6 2-Methylpropan-2-ol (tert-butyl alcohol). Warning: Low flash point.
A3 Apparatus
A3.1 Polyethylene bottle: 1000mL capacity, wide mouth with screw cap. A3.2 Glass volumetric flask: 1000cm2 capacity. A3.3 Graduated pipette: 10cm2 capacity. A3.4 Graduated glass cylinder: 100cm2 capacity and 1000cm2 capacity. A4 Preparation steps
Warning: This preparation step must be carried out in a fume hood, and protective glasses and disposable plastic gloves must be worn. A4.1 Preparation of test liquid
A4.1.1 Base fuel mixture
Mix equal volumes of 2,2,4-trimethylpentane and toluene to prepare GB/T1690 liquid C and store in a dark glass bottle. Mix liquid C specified in GB/T1690, methanol and 2-methylpropan-2-ol in a volume ratio of 80:15:5 to prepare a base fuel and store in a dark glass bottle.
A4.1.2 Copper ion stock solution (1 mg/dm2) Add an appropriate volume of copper ion concentrate to the base fuel to prepare a 1000 cm copper ion solution (Cu-1) with a concentration of 1.140 mg/dm2. Store in a dark glass bottle. 387
HG/T 3665--2000
Add 100cm of Cu-1 to 1040cm of base fuel to make a 0.1mg/cm2 copper ion solution (Cu-2). Store in a dark glass bottle.
Add 100cm of Cu-2 to 990cm2 of base fuel to make a 1.0mg/cm2 copper ion stock solution (CSS). Store in a dark glass bottle.
A4.1.3 Preparation of Oxidized Fuel Test Liquid Use the mixture specified in Table A1 to prepare an oxidized gasoline test liquid of the required working strength. Store in a polyethylene bottle in the dark for no more than four weeks. Immediately after mixing and before subsequent use, check the peroxide index by the titration test method described in A5. Use a 1000cm2 volumetric flask to hold 500cm2 of base fuel, add tert-butyl hydroperoxide solution and copper ion stock solution (CSS), then fill to 1000cm° with base fuel, and shake thoroughly to dissolve the water in the hydrogen peroxide solution in the ethanol phase of the base fuel. Table A1 Preparation of Oxidized Fuel Test Liquid
Expected Peroxide Number
70% Tert-butyl Hydroperoxide Solution
Note: 1 Peroxide Number (PN) = 1mmol/dm2. Copper Ion Stock Solution (CSS)
Base Fuel
To 1000cm
Recheck the PN of the test liquid after every 70h of use. If it drops below 80PN, replace the old test liquid with a new test liquid.
A5 Titration of Peroxide Number of Oxidized Fuel Test LiquidA5.1 Scope
This clause specifies a titrimetric method for determining the peroxide number of oxidized ("acidified") gasoline test fluids prepared by the procedure specified in A4.
This method can be used to determine the peroxide number of oxidized gasoline test fluids during immersion tests. The following observations should be made: a) Most immersion tests involving elastomers will result in yellowing of the test fluid due to the extraction of compounding ingredients from the rubber. This should be taken into account in determining the titration endpoint.
b) Compounding ingredients extracted from the material during the test have the ability to release free iodine from the iodide solution. Therefore, blanks should be made in duplicate immersion tests using a base fuel that does not contain peroxides. This method can also be used (with certain provisions) to determine the loss of peroxide number from the test fluid used during immersion tests in order to determine the amount of test fluid that needs to be replenished.
A5.2 Reagents
Unless otherwise specified, only analytical grade reagents and distilled water or water of equivalent purity should be used in the analysis. A5.2.1 Potassium iodide: 100 g/dm solution, stored in a dark reagent bottle. If the solution gives a peroxide number of 2 during blank titration, discard it.
A5.2.2 Standard sodium thiosulfate titration solution: c(Na2S,0,) = 0.1 mol/dm. A5.2.3 Acetic acid/propan-2-ol mixture: Mix 100 mL of glacial acetic acid and 1150 ml of propan-2-ol and store in a glass bottle. A5.3 Apparatus
A5.3.1 Erlenmeyer flask: ground mouth, volume 250 cm2. A5.3.2 Condenser: Allihn or Liebig water-cooled, with ground joint for connection to the Erlenmeyer flask (A5.3.1). A5.3.3 Glass measuring cylinder: volume 100 cm2. A5.3.4 Hot plate or other heating means: should be suitable for heating the conical flask equipped with a condenser to reflux the reagents. A5.3.5 Glass pipette: capacity 10 cm. A5.4 Procedure
A5.4.1 Add 25 m acetic acid/propan-2-ol mixture to a 250 cm2 conical flask. A5.4.2 Add 10 cm potassium iodide solution to the conical flask. 388
HG/T3665—2000
A5.4.3 Use a pipette to accurately transfer 2 cm2 of the oxidized gasoline test liquid prepared in A4.1.3 to the conical flask. A5.4.4 Install the condenser on the conical flask and gently reflux on the hot plate for 5 minutes to release free iodine. A5.4.5 Cool the flask in a cold water bath and rinse the condenser downward with 5 cm2 of water. A5.4.6 After removing the condenser, titrate with sodium thiosulfate standard titration solution until the yellow color just disappears. Record the volume V1 of sodium thiosulfate standard titration solution consumed.
A5.4.7 Repeat steps A5.4.1 to A5.4.6 to perform a blank test, but omit the addition of the oxidized gasoline test liquid (step A5.4.3). Record the volume V2 of sodium thiosulfate standard titration solution consumed. This volume should not exceed 0.1 cm3. A5.5 Expression of analytical results
The peroxide number (PN) of the oxidized gasoline test liquid is calculated according to formula (A1): 1000c(V,-V2)
Where: V. -—The volume of the oxidized gasoline test liquid taken for determination in A5.4.3, cm; V,-—The volume of the sodium thiosulfate standard titration solution used for the real titration in A5.4.6, cm; V,-—The volume of the sodium thiosulfate standard titration solution used for the blank titration in A5.4.7, cm; c---The actual concentration of the sodium thiosulfate standard titration solution used, mol /cm. Appendix B
(Standard Appendix)
Cleanliness and extractables test
B1 Scope
This appendix specifies the method for quantitative determination of insoluble impurities ("inclusions"), liquid C dissolved substances, and waxy extracts in pure rubber hoses and hoses used in liquid fuel systems.
B2 Principle
Fill a certain amount of liquid C into a pure rubber hose or hose sample and place it at room temperature for 24 hours. Subsequently, the sample is emptied and the inside of it is flushed with liquid C by gravity flow.
Collect all the solution, filter out the insoluble impurities, dry and weigh, evaporate the remaining solution to as low as 100% and calculate the total dissolved liquid C. Dissolve the waxy extract from the residue with methanol. Evaporate the solution to dryness and weigh the waxy extract. B3 Apparatus and Materials
B3.1 Glass funnel.
Evaporating blood.
Beaker.
Fuel evaporation equipment: connected to the fume hood. B3.4
B3.5 Ventilation drying oven: capable of maintaining the temperature at (85 ± 5)°C. Balance: accurate to 0.1 mg. bzxZ.net
Sintered glass filter: porosity P3. B3.7
B3.8Liquid C shall comply with GB/T1690.
B3.9Methanol: minimum purity is 99%.
B3.10Metal stopper.7 is the volume of the sodium thiosulfate standard titration solution used for blank titration, cm; c---the actual concentration of the sodium thiosulfate standard titration solution used, mol/cm. Appendix B
(Standard Appendix)
Cleanliness and Extract Test
B1 Scope
This appendix specifies the method for quantitative determination of insoluble impurities ("inclusions"), liquid C dissolved, and waxy extracts in pure rubber hoses and hoses used in liquid fuel systems.
B2 Principle
A certain amount of liquid C is filled into a pure rubber hose or hose sample and placed at room temperature for 24 hours. Subsequently, the sample is emptied and the inside is flushed with liquid C by gravity flow.
Collect all the solution, filter out the insoluble impurities, dry and weigh, and evaporate the remaining solution to dryness, from which the total liquid C dissolved can be calculated. The waxy extract is dissolved from the residue with methanol. The solution thus obtained is evaporated to dryness and the waxy extract is weighed. B3 Apparatus and Materials
B3.1 Glass funnel.
Evaporated blood.
Beaker.
Fuel evaporation equipment: connected to the fume hood. B3.4
B3.5 Ventilation drying oven: capable of maintaining the temperature at (85 ± 5)°C. Balance: accurate to 0.1 mg.
Sintered glass filter: porosity P3. B3.7
B3.8Liquid C is in accordance with GB/T1690.
B3.9Methanol: minimum purity is 99%.
B3.10Metal stopper.7 is the volume of the sodium thiosulfate standard titration solution used for blank titration, cm; c---the actual concentration of the sodium thiosulfate standard titration solution used, mol/cm. Appendix B
(Standard Appendix)
Cleanliness and Extract Test
B1 Scope
This appendix specifies the method for quantitative determination of insoluble impurities ("inclusions"), liquid C dissolved, and waxy extracts in pure rubber hoses and hoses used in liquid fuel systems.
B2 Principle
A certain amount of liquid C is filled into a pure rubber hose or hose sample and placed at room temperature for 24 hours. Subsequently, the sample is emptied and the inside is flushed with liquid C by gravity flow.
Collect all the solution, filter out the insoluble impurities, dry and weigh, and evaporate the remaining solution to dryness, from which the total liquid C dissolved can be calculated. The waxy extract is dissolved from the residue with methanol. The solution thus obtained is evaporated to dryness and the waxy extract is weighed. B3 Apparatus and Materials
B3.1 Glass funnel.
Evaporated blood.
Beaker.
Fuel evaporation equipment: connected to the fume hood. B3.4
B3.5 Ventilation drying oven: capable of maintaining the temperature at (85 ± 5)°C. Balance: accurate to 0.1 mg.
Sintered glass filter: porosity P3. B3.7
B3.8Liquid C is in accordance with GB/T1690.
B3.9Methanol: minimum purity is 99%.
B3.10Metal stopper.
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.