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This standard is modified in relation to the international standard "Determination of Flash Point - Pensky-Martens Closed Cup Method (English edition)" (ISO 2719: 2002).
This standard is redrafted according to ISO 2719: 2002.
In order to suit China's national conditions, some revision was made in this standard during the adoption of ISO 2719: 2002.Compared with ISO 2719: 2002, major technical differences in this standard are as follows:
- Relevant regulations on that this standard also may be adopted for the determination for the jet fuel of the flash point below 40℃ were added in the form of note in this standard scope;
- Partial normative references in this standard are replaced by corresponding national standards;
- Note was added in the reproducibility requirements in this standard that "the reproducibility of this precision is not applicable to No.20 aviation lubricating oil."
This standard replaces "Petroleum Products - Determination of Flash Point - Closed Cup Method" (GB/T 261-1983). GB/T 261-1983 was formulated by reference to ISO 2719: 1973.
Compared with GB/T 261-1983, main changes in this standard are as follows:
- Application scope in this standard is extended. Besides the petroleum products, this standard is still applicable to the flash point of chemical products such as varnish that doesn’t form a surface film and paint;
- Uniform test procedures are specified for various samples and the stirring rotation speed is not specified definitely in GB/T 261-1983. Description is respectively made for various samples according to Procedure A and Procedure B and heating rate and stirring rotation speed are specified definitely in the test procedures in this standard.
- Relevant items such as terms, sample treatment and apparatus calibration were added in this standard;
- Two internal standard thermometers were specified in GB/T 261-1983 while three bar thermometers were specified in this standard and may be selected according to the expected flash point of samples;
- It was specified that "Reignition is carried out after the initial ignition is caused on the sample; if the flash fire is able to be continued, the test result shall be considered valid." while it was specified that "the difference between the observed flash point of the sample and its initial ignition temperature shall be within the range of 18℃~28℃";
- The use of automatic apparatus was added in this standard but it was specified that “the arbitration test is subject to the manual test results”;
- The provision "the result is to within 0.5℃" was added in this standard;
- Precision was modified in this standard and respectively given for various samples according to Procedure A and Procedure B;
- Four appendixes were added in this standard: Appendix A "Apparatus Calibration", Appendix B "Pensky-Martens Closed Flash Point Tester", Appendix C "Thermometer Specification" and Appendix D "Thermometer Adaptor".
Appendixes B and C in this standard are normative while Appendixes A and D are informative.
This standard was proposed by the National Technical Committee on Petroleum Products and Lubricants of Standardization Administration of China.
This standard is under the jurisdiction of Subcommittee on Petroleum Fuel and Lubricants under National Technical Committee on Petroleum Products and Lubricants of Standardization Administration of China.
Drafting organization of this standard: SINOPEC CORP. Research Institute of Petroleum Processing (RIPP).
Chief drafting staffs of this standard: Guo Tao and Chen Jie.
The previous edition of the standards replaced by this standard are as:
- GB 261-1964, GB 261-1977 and GB/T 261-1983.
Introduction
Flash point value is able to be used in aspects such as transportation, storage, operation, safety management and may be regarded as the classification parameter to define "inflammable substance" and "combustible substance". Their accurate definitions are detailed in their own special laws and regulations and relevant standards.
Flash point value may be used to indicate where high volatile or combustible substance is present in relatively non-volatile or combustible substance. Flash point test is the first step for other research for unknown materials.
Flash point test is not able to be used for potentially instable, labile or explosive samples, unless otherwise confirmed within the temperature range specified in this standard. Specified amount of such samples contacted between metal components of heating and flash point testers won't produce decomposition, explosion or other adverse effects.
Flash point test results obtained on halohydrocarbon-containing samples shall be analyzed carefully as such samples possibly will produce abnormal results.Contents
1 Scope 1
2 Normative References 1
3 Terms and Definitions 2
4 Summary of Method 3
5 Reagents and Materials 3
6 Apparatus 3
7 Apparatus Preparation 4
8 Sampling 4
9 Sample Handling 4
10 Test Procedure 5
11 Calculation 6
12 Expression of Results 7
13 Precision 7
14 Test Report 8
Appendix A (Informative) Apparatus Verification 9
Appendix B (Normative) Pensky-Martens Closed Flash Point Tester 12
Appendix C (Normative) Thermometer Specification 17
Appendix D (Informative) Thermometer Adaptor 18
Determination of Flash Point - Pensky-Martens Closed Cup Method
閃點的測定 賓斯基-馬丁閉口杯法
Warning: the use of this standard may involve hazardous materials, operations and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this standard to establish corresponding safety and protection measures and determine the applicability of regulatory limitations prior to use.
1 Scope
1.1 This standard specifies methods for determination of the flash point of the combustible liquid, liquids with suspended solids, liquids that tend to form a surface film under the test conditions and other liquids by the Pensky-Martens closed flash point tester. This standard is applicable to samples with a flash point above 40℃.
Note: 1 Although kerosene with a flash point above 40℃, they may be also tested by using this standard; however, the flash point of kerosene is generally determined according to ISO 13736.Generally, the flash point of the used lubricating oil is determined according to GB/T 3536.
2 This standard may also be used to determine the jet fuel with the flash point below 40℃. However, the precision is not verified.
1.2 The test procedures in this standard include Procedure A and Procedure B.
1.2.1 Procedure A is applicable to paints that do not form a surface film and varnish, used lubricating oils and other petroleum products not covered in Procedure B.
1.2.2 Procedure B is applicable to residual fuel oils, cutback bitumen, used lubricating oils, liquids that tend to form a surface film, liquids with suspended solids and highly viscous materials (such as polymer solution and adhesives).
Note: during the monitoring of the lubricating oil system, for the comparison of flash points of used and unused lubricating oils, Procedure A also may be used to determine the flash point of used lubricating oils. However, the precision of this standard is only applicable to Procedure B.
1.3 This standard is not applicable to water-borne paints or liquids containing highly volatile materials.
Note 1: the flash point of water-borne paints may be determined according to GB/T 7634. For the flash point of liquids containing highly volatile materials may be determined according to ISO 1523 or GB/T 7634.
2 The precision data in this standard is only valid within the range of flash point described in Chapter 13.
2 Normative References
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding amending errors in the text) to, or revisions of, any of these publications do not apply. However, all parties coming to an agreement according to this standard are encouraged to study whether the latest editions of these documents are applicable. To the applicable references not dated, the latest edition of it was applicable to this standard.
GB/T 3186-2006 "Paints Varnishes and Raw Materials for Paints and Varnishes - Sampling" (GB/T 3186-2006, ISO 15528: 2000, IDT)
GB/T 3536 Petroleum Products - Determination of Flash and Fire Points - Cleveland Open Cup Method (GB/T 3536-2008, ISO 2592 2000, MOD).
GB/T 4756 Petroleum Liquids - Manual Sampling (GB/T 4756-1998, eqv ISO 3170: 1988)
GB/T 6683 Petroleum Products - Determination of Precision Data in Relation to Methods of Test (GB/T 6683-1997, neq ISO 4259: 1992)
GB/T 7634 Petroleum and Related Products - Determination of Lower Flashpoint - Rapid Equilibrium Method
GB/T 15000.3 Directives for the Work of Reference Materials (3) General Principles and Statistic Methods for Certification of Reference Materials (GB/T 15000.3-1994, neq ISO Guide 35)
GB/T 15000.7 Directives for the Work of Reference Materials (7) - General Requirements for the Competence of Reference Material Producers (GB/T 15000.7-2001, ISO Guide 34: 2000, IDT)
GB/T 15000.8 Directives for the Work of Reference Materials (8) - Uses of Certified Reference Materials (GB/T 15000.8-2003, ISO Guide 33, IDT)
GB/T 20777 Paints and Varnishes - Examination and Preparation of Samples for Testing (GB/T 20777-2006, ISO 1513: 1992, IDT)
SY/T 5317 Petroleum Liquid - Automatic Pipeline Sampling (SY/T 5317-2006, ISO 3171: 1988, IDT)
ISO 1523 Determination of Flash Point - Closed Cup Equilibrium Method
ISO 13736 Petroleum Products and Other Liquids - Determination of Flash Point - Abel Closed-cup Method
ASTM E1 Standard Specification for ASTM Liquid-in-Glass Thermometer
IP Standard Annals for Test Method of Petroleum and Petroleum Products Appendix A
3 Terms and Definitions
For the purpose of this standard, the following terms and definitions apply.
3.1
Flash point
The lowest temperature of the sample, corrected to a barometric pressure of 101.3kPa, at which the application of an ignition source causes the vapor of the sample to ignite and the flame to propagate across the liquid surface under the specified conditions of test.
4 Summary of Method
The sample is poured in the test cup, stirred at the specified rate and heated at constant rate. An ignition source is directed through an opening in the test cup cover at regular temperature intervals with simultaneous interruption of stirring to cause the sample vapor to ignite immediately and propagate over the liquid surface. This temperature is regarded as the flash point under the ambient barometric pressure and then corrected to the flash point by a formula under standard atmosphere pressure
5 Reagents and Materials
5.1 Cleaning solvent: for the removal of traces of samples from the test cup and cover.
Note: the selection of the cleaning solvent will be based on the tested sample and the viscosity of the residue. Low volatility aromatic (benzene-free) solvents may be used to remove traces of oils, mixed solvents, such as toluene, acetone and methanol, may be effective for the removal of gum-type deposits.
5.2 Verification liquids: as described in in Appendix A.
6 Apparatus
6.1 Pensky-Martens closed flash point tester: see Appendix B.
6.1.1 If automated equipment is used, ensure that it has been established that the determination results are within the precision specified in this standard and that the test cup and cover assembly conform to the dimensional and mechanical requirements as specified in Appendix B and the user shall ensure that all the operation is performed according to the instructions.
Note: under certain circumstances, the use of electric ignition and flame ignition may give different results. Electric ignition sources may give variable results.
6.1.2 In cases of dispute, unless otherwise specified, the arbitration test is subject to the manual test results of the flash point using a flame ignition source.
6.2 Thermometers: low, medium and high range, conforming to those specified in Appendix C. The thermometer shall be selected according to the expected flash point of the sample.
Note: other types of temperature measuring equipment may also be used, provided that they meet the requirements for accuracy and sensitivity.
6.3 Barometer: accurate to 0.1kPa. Barometers pre-corrected to give sea-level readings, such as those used at weather stations and airports, shall not be used.
6.4 Heating bath or oven: for warming the sample, if required, capable of controlling the temperature within ±5℃. The oven shall be ventilated and constructed in such as way that it will not cause ignition of any combustible vapor that may be produced where the sample is heated.
1 Scope
2 Normative References
3 Terms and Definitions
4 Summary of Method
5 Reagents and Materials
6 Apparatus
7 Apparatus Preparation
8 Sampling
9 Sample Handling
10 Test Procedure
11 Calculation
12 Expression of Results
13 Precision
14 Test Report
Appendix A (Informative) Apparatus Verification
Appendix B (Normative) Pensky-Martens Closed Flash Point Tester
Appendix C (Normative) Thermometer Specification
Appendix D (Informative) Thermometer Adaptor
