EN 15794:2009 – Determination of explosion points of flammable liquids
1 Scope
This European Standard specifies a test method to determine the explosion points of flammable liquids in air.
This European Standard applies to flammable liquids at atmospheric pressure and at temperatures in the range from – 50 °C to 300 °C.
This European standard must not be applied to explosives or materials which, under the test conditions, are thermally unstable liquids (e.g. polymerizing/oxidizing materials).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 1 3237:2003, Potentially explosive atmospheres – Terms and definitions for equipment and protective systems intended for use in potentially explosive atmospheres
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1 3237:2003 apply.
4 Principle of the test method
The test sample is placed in a cylindrical vessel and heated up to a specified temperature. After having reached equilibrium conditions between the liquid phase and the gas phase at the set temperature ignition is initiated using a series of induction sparks. It is observed whether a flame detachment or a temperature rise occurs. The temperature of the test apparatus is raised or lowered stepwise, until just no ignition is observed.
5 Test equipment
5.1 Reagents and Materials
5.1.1 Flammable liquid:
The flammable liquid may be:
a single liquid or a defined mixture of liquids;
a process sample (of known or unknown composition).
When a pure liquid or a mixture of defined composition is used, the purity of each liquid shall be 99,8 % mol.
or better. In the case of a mixture or a process sample of undefined composition the sample should be characterised so that the origin as well as the related process conditions can be identified.
5.1.2 Sampling and Storage
Sampling should be carried out if possible according to the procedures given in EN ISO 31 70, EN ISO 31 71 ,
EN ISO 1 5528 or an equivalent National Standard.
Sufficient sample volume for testing shall be placed in a tightly sealed container appropriate to the material being sampled. At the beginning of the tests, the sample container shall be filled to between 85 % and 95 % of its capacity.
The samples shall be stored in conditions that minimize vapour loss and pressure build up to avoid losing volatile components.
If possible, the sample should be stored in its container either at ambient temperature, or about 5 K below the test starting temperature (expected explosion point), whichever is the lower temperature. The sample shall be maintained at this temperature, or lower, until all tests on the sample are completed.
Viscous liquids, liquids which crystallise on cooling, polymerize or separate are to be stored at just above the temperature at which this occurs.
Sample containers are to be kept closed before and after sampling to avoid alterations of the sample (e.g.evaporation of volatile constituents/impurities).
5.2 Apparatus
Apparatus see Figure 1
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