Determination of flash point- Rapid equilibrium closed cup method
1 Scope
This standard specifies a method for the determination of the closed cup flash point of paints (including water-borne paints), varnishes, paint binders, adhesives, solvents, petroleum, and related products having closed cup flash points within the range of − 30 °C to 300 °C. When used in conjunction with the flash detector (A.1.6), this standard is also suitable for the determination of the flash point of fatty acid methyl esters (FAME).
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 to (excluding correction to), or revisions of, any of these publications do not apply. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, the latest edition of the normative document applies.
GB/T 3186 Paints varnishes and raw materials for paints and varnishes - Sampling (GB/T 3186 - 2006, ISO 15528 : 2000, 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 3170 Petroleum and its liquid products - Manual sampling
3 Terms and definitions
For the purposes of this standard, the following terms and definitions apply.
3.1
flash point
lowest temperature of the test portion (as measured in the prescribed manner), corrected to a barometric pressure of 101.3 kPa, at which application of a test flame causes the vapour of the test portion to ignite momentarily and the flame to propagate across the surface of the liquid under the specified conditions of test
4 Principle
A test portion of specified volume is introduced into the test cup, which is maintained at the temperature of the estimated flash point of the material under test. After a specified time, a test flame is applied and the presence or absence of a flash observed. Further tests, with fresh test portions at different temperatures, are carried out until the flash point is determined to the sensitivity specified.
5 Reagents and materials
5.1 Cleaning solvent
An appropriate solvent for the removal of traces of the previous test portion from the test cup and cover.
Note: The choice of solvent will depend upon the previous material tested and the tenacity of the residue. Low volatility aromatic (benzene-free) solvents may be used to remove traces of oil, and mixed solvents such as toluene- acetone-methanol may be effective for the removal of gum-type deposits.
5.2 Verification liquids
A series of certified reference materials (CRM) and/or secondary working standards (SWS) as described in Annex C.
6 Apparatus
6.1 General
The apparatus is described in Annex A, and this includes the details of the test cup and cover assembly, together with dimensions and special requirements. These are shown in Figure A.1 to Figure A.5. The measurement of flash points over the whole range of − 30 °C to 300 °C may require more than one instrument.
6.2 Syringes
6.2.1 2 mL syringe, which may be adjusted to deliver 2.00 mL ± 0.05 mL and equipped, if required, with a needle suitable for use with the apparatus at test temperatures up to and including 100 °C. When testing FAME, a 2 mL sample is used at all temperatures.
6.2.2 5 mL syringe, which may be adjusted to deliver 4.00 mL ± 0.10 mL and equipped, if required, with a needle suitable for use with the apparatus at test temperatures above 100 °C. A 5 mL syringe is not required when testing FAME.
6.3 Barometer, accurate to 0.1 kPa. Barometers precorrected to give sea-level readings, such as those used at weather stations and airports, shall not be used.
6.4 Heating bath or oven (optional), for warming the samples, if required, and capable of controlling the temperature to ± 5 °C. If an oven is used, it shall be intrinsically safe for hydrocarbon vapours.
It is recommended that the oven be of explosion-protected design.
6.5 Cooling bath or freezer (optional), for cooling the samples, if required, and capable of cooling the sample to 10 °C below the expected flash point, and controlling the temperature to ± 5 °C. If a freezer is used, it shall be of an explosion-protected design.
6.6 Draught shield (optional), if required to minimize draughts, fitted at the back and on two sides of the instrument.
Note: A shield, 350 mm high, 480 mm wide and 240 mm deep, is suitable.
6.7 Cup insert (optional). See Annex D.
Note: For samples that are difficult to remove, a thin metal cup insert can be used.
7 Apparatus preparation
Foreword I
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Reagents and materials
6 Apparatus
7 Apparatus preparation
8 Sampling
9 Sample handling
10 Procedure
11 Calculation
12 Expression of results
13 Precision
14 Test report
Annex A (normative) Flash point test apparatus
Annex B (normative) Thermometer specifications
Annex C (informative) Verification of apparatus
Annex D (informative) Use of a cup insert
Bibliography
