EN 589 Automotive Fuels - LPG - Requirements and Test Methods

A European standard, “EN 589 Automotive fuels - LPG - Requirements and test methods”, describes the requirements and test methods for marketed and delivered automotive LPG (liquefied petroleum gas).

LPG is defined as a low-pressure liquefied gas composed of one or more light hydrocarbons, mainly propane, propene, butane, butane isomers, butenes with traces of other hydrocarbon gases.

The standard in question is applicable to automotive LPG used in LPG engine vehicles designed to operate with automotive LPG.

Attention is drawn to the risk of fire and explosion when working with LPG and the health hazards that arise from inhaling excessive amounts of LPG.

LPG is a highly volatile hydrocarbon liquid normally stored under pressure. If the pressure is released, large volumes of gas are produced that form flammable mixtures with air in the range of approximately 2 percent (V/V) to 10 percent (V/V).

This European standard covers the sampling, handling and testing of LPG. Naked flames, unprotected electrical equipment, electrostatic hazards and similar hazards are ignition sources for LPG. In addition, LPG in liquid form can cause frostbite on the skin. LPG is heavier than air and will accumulate in cavities. There is a risk of asphyxiation if LPG is inhaled in high concentrations.

For the purposes of this standard, liquefied petroleum gas (LPG) means petroleum gas that can be stored or processed in liquid phase under moderate pressure conditions and at ambient temperature, consisting predominantly of propane and butane gases, with small proportions of propene, butenes and pentanes/pentenes.

LPG samples for testing should be taken as described in the standard “BS EN ISO 4257 Test methods for petroleum and its products – Liquefied petroleum gases – Sampling method” or in accordance with the requirements of national standards or regulations for sampling automotive LPG. National requirements should be detailed or referenced in a national annex to this standard.

In view of the sensitivity of some of the test methods referred to in this standard, particular care should be taken to comply with any guidance on sampling containers contained in this standard. It is important that the sampling procedure is followed in detail to avoid evaporation losses. Before sampling from the distributor hose, 20 l of product should be pumped or recirculated to obtain a representative sample.

The information and label dimensions to be marked on distribution pumps and nozzles used in automotive LPG distribution must comply with the “EN 16942 Fuels - Determination of vehicle compatibility - Graphical expression for consumer information” standard.

In this standard, the requirements and test methods are described as follows:

• General: When tested by the test methods given in the table given in the standard, automotive LPG fuel shall comply with the limiting requirements given in this table. Five classes, A, B, C, D and E, are given to enable national seasonal limits to be set for each period of the year for minimum vapour pressure. In the annex to this standard, each country shall specify which classes it has adopted to achieve a minimum vapour pressure of 150 kPa (gauge) all year round and shall detail the period of validity of the selected class. Liquefied petroleum gases for automotive purposes shall be free from any foreign matter or contaminants which would render the fuel unacceptable for use in suitable engines.
• Water content: Liquefied petroleum gases for automotive purposes shall not contain free water on visual inspection at 0°C and at saturated vapour pressure. For propane-rich mixtures containing at least 60% m/m propane, compliance with EN ISO 13758 equally meets this requirement. The addition of up to 2 000 mg/kg of methanol is permitted for operating purposes. No other antifreeze shall be added.
• Odor: When tested in accordance with the procedure described in the Annex to the standard, the odor of the gas shall be characteristic (i.e., distinct and unpleasant) and detectable at a concentration in air of 20 percent of the lower flammability limit (Annex A). Since unpleasantness is subjective, the odor shall be a warning and invite the user to search for the leak. Alternatively, alternative test methods may be used if the odor test demonstrates the ability of these detection methods to measure odor or a related parameter at least equal to the test method described in Annex A. Such alternative procedures shall be specified in detail or incorporated by reference in the Annex to this Standard.
• Density: If a density report is required, EN ISO 3993 or EN ISO 8973 standards shall be followed. All test methods referred to in this standard shall include a statement of sensitivity. In cases of disagreement, the procedures for resolving disagreement and interpreting results based on test method sensitivity as described in EN ISO 4259-2 shall be used. In cases of disagreement regarding evaporation residue, EN 15470 or EN 15471 standards shall be used. In cases of disagreement regarding vapour pressure, EN ISO 4256 standard shall be used. In cases of disagreement regarding total diene content and propane content, EN 27941 standard shall be used. In cases of disagreement regarding total sulphur content, prEN 17178 standard shall be used.

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