EN 15471-2017 pdf download.Liquefied petroleum gases – Determination of dissolved residues – High-temperature gravimetric method.
This EN 15471 specifies a method for determining the dissolved residual matter in liquefied petroleum gases (LPG). which remains after evaporation at 105 °C using the jet evaporation equipment described in EN ISO 6246.
The measurement range is from 20 mg/kg to 100 mg/kg. Higher concentrations can be determined by adjusting the sample size.
The precision data of the method have been determined from 20 mg/kg to 100 mg/kg. with samples amount from lOOgtoSOg.
NOTE An alternative European Standard. EN 15470 [1], specifies a gas chromatography method.
WARNING — The use of this standard can 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 users of this standard to take appropriate measures to ensure the safety and health of personnel prior to application of the standard, and fulfil statutory and regulatory requirements for this purpose
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN ISO 4257, Liquefied petroleum gases. Method of sampling (ISO 4257)
EN ISO 6246, Petroleum products – Gum content of fuels -Jet evaporation method (ISO 6246)
3 Terms and definitions
For the purposes of this document, the following term and definition applies.
3.1
liquefied petroleum gas
LPG
petroleum gas that can be stored and/or handled in the liquid phase under moderate conditions of pressure and at ambient temperature, consisting predominantly of propane and butanes, with small proportions of propene, butenes and pentanes/pentenes
4 Principle
5.3 Carbon dioxide, solid for the cooling bath.
5.4 Air, supply of filtered air at a pressure not more than 34,5 kPa.
5.5 Propan-2-one (acetone), analytical grade.
6 Apparatus
6.1 Sample cylinder, of a total mass compatible with the balance (6.10) used; preferably made of
stainless steel fitted with two stainless steel valves free of oily materials, conforming to EN ISO 4257.
6.2 In-lIne filter support, made of stainless steel and for use at suitable high pressure.
6.3 Filter discs, plain membrane with nominal pore dimension of 0,8 lAm.
NOTE This method enables to quantify the total dissolved residual matter in LPG; the purpose of the filter disc is to remove any particulate matter present in the LPG sample which would contribute to the total residual matter.
6.4 Cooling coil, made by coiling 4 m of stainless steel tube of external diameter 6 mm and internal diameter 4 mm onto a mandrel of a diameter of approximately 50 mm and fitted with the necessary connections (see 3 in Figure 2).
6.5 Cooling bath, comprised of a 0,51 to 21 Dewar flask, filled with propan-2-ol (5.2) cooled by adding solid carbon dioxide (5.3), to achieve a temperature of approximately —77 °C.
6.6 Beaker, made of glass, with a capacity of 11.
6.7 Boiling regulating rod, made of glass and a length of about 28 cm.
6.8 Beaker, made of glass and with a capacity 100 ml.
6.9 Balance for weighing the sample cylinder (6.1), capable of weighing to the nearest 1 g.
6.10 Analytical balance, capable of weighing to the nearest 0,1 mg.
6.11 Desiccator, (a drying agent is not recommended).
6.12 Apparatus, for determining evaporation residues by air jet evaporation according to Figure 1 (for further information, see EN ISO 6246).
6.13 Oven, static type (without fan assisted circulation), explosion-proof, capable of heating to (105 ± 5) °C.
8.2 Evaporation of the LPG
Place the beaker with the sample (see 8.1) into an explosion-proof hood. Leave to evaporate until there is no visible volume of liquid left in the beaker.
8.3 Jet evaporation procedure
The 100 ml beaker (6.8) is washed/rinsed with acetone (5.5) and distilled water and then dried at 105 °C for 30 mm.
When found necessary one may also immerse the beaker in a mildly detergent solution or. for a deeper cleaning action, use an oxidative acid cleaning solution. After a few hours soaking period, rinse the beaker with distillated water and dry.
After cooling, this 100 ml beaker Is placed in a desiccator (6.11) for 30 mm, and then weighed to the nearest 0,1 mg to obtain the mass m3. After evaporation of the sample, rinse the walls of the 11 beaker (6.6) twice very carefully with approximately 20 ml n-heptane (5.1) each time and transfer the contents into the previously prepared 100 ml beaker. Place the 100 ml beaker into the jet evaporation apparatus (6.12) as shown in Figure 1 and let the contents evaporate for a period of 30 mm at 105 °C with an air stream of 18 1/mm to 24 1/mm. Remove the beaker from the jet evaporation apparatus and place ft in a desiccator for between 30 mm and 1 h. Finally, weigh the beaker to the nearest 0,1 mg to obtain the mass m. The difference between this mass and the tare mass of the beaker gives the mass mr of the dissolved residue obtained during the test.EN 15471-2017 pdf download.