SIST EN ISO 13757:1998

SLOVENSKI STANDARD
01-maj-1998
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PHWRGD,62
Liquefied petroleum gases - Determination of oily residues - High-temperature method
(ISO 13757:1996)
Flüssiggase - Bestimmung der öligen Rückstände - Hochtemperaturmethode (ISO
13757:1996)
Gaz de pétrole liquéfiés - Détermination des résidus huileux - Méthode a haute
température (ISO 13757:1996)
Ta slovenski standard je istoveten z: EN ISO 13757:1996
ICS:
75.160.30 Plinska goriva Gaseous fuels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL
ISO
STANDARD
First edition
1996-07-15
Liquefied Petroleum gases -
Determination of oily residues -
High-temperature method
Gaz de p&role liqu&fi& - D&ermination des r&idus huileux - Methode
6 haute tempbrature
Reference number
ISO 13757:1996(E)
ISO 13757:1996(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide
federation of national Standards bodies (ISO member bodies). The work
of preparing International Standards is normally carried out through ISO
technical committees. Esch member body interested in a subject for
which a technical committee has been established has the right to be
represented on that committee. International organizations, governmental
and non-governmental, in liaison with ISO, also take part in the work. ISO
collaborates closely with the International Electrotechnical Commission
(1 EC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard ISO 13757 was prepared by Technical Committee
ISO/TC 28, Petroleum products and lubrkan ts.
Annex A of this International Standard is for information only.
0 ISO 1996
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronie or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-1 211 Geneve 20 l Switzerland
Printed in Switzerland
ii
ISO 13757:1996(E)
INTERNATIONAL STANDARD 0 ISO
- Determination of oily
Liquefied Petroleum gases
- High-temperature method
residues
- The use of this International Standard may involve hazardous materials, operations
WARNING
and equipment. This International Standard does not purport to address all of the safety Problems
associated with its use. lt is the responsibility of the User of this Standard to establish appropriate
safety and health practices and determine the applicability of regulatory Iimitations Prior to use.
3 Definition
1 Scope
For the purposes of this International Standard, the
This International Standard specifies a method for the
following definition applies.
determination of the residual matter in liquefied pet-
roleum gases (LPG) that remains after evaporation at
105 “C. This material, termed “oily residues ”, rep- 3.1 liquefied Petroleum gas: Hydrocarbon gas that
resents those products that are deposited in tan be stored and/or handled in the liquid Phase under
moderate conditions of pressure and at ambient tem-
vaporizers that are subject to a heat input greater than
perature. lt consists essentially of C, and C, alkanes
that of ambient evaporation.
or alkenes, or a mixture of these, contains generally
less than 5 % by liquid volume of material of higher
carbon number, and has a gauge vapour pressure not
exceeding approximately 1 600 kPa at 40 “C.
2 Normative references
The following Standards contain provisions which,
through reference in this text, constitute provisions 4 Principle
of this International Standard. At the time of publi-
cation, the editions indicated were valid. All Standards A known mass of filtered LPG Sample is concentrated
are subject to revision, and Parties to agreements by evaporation. The concentrate is transferred into an
based on this International Standard are encouraged evaporation flask using dichloromethane (methylene
chloride) and then evaporated by means of a rotary
to investigate the possibility of applying the most re-
evaporator. The oily residue remaining after this
cent editions of the Standards indicated below.
evaporation is placed in an oven at 105 “C for 1 h,
Members of IEC and ISO maintain registers of cur-
rently valid International Standards. then cooled and weighed.
ISO 3696:1987, Water for analytical laboratory use -
Specifica tion and tes t me thods.
5 Reagents
Liquefied Petroleum gases -
ISO 4257:1988,
5.1 Acetone, analytical grade.
Method of sampling.
0 ISO
ISO 13757:1996(E)
6.5 Cooling bath, comprising a 3-dm3 Dewar flask,
5.2 Ammonium peroxodisulfate, (N H,),S,O,, in
three-quarters filled with an appropriate liquid, e.g.
sulfuric acid Solution.
acetone cooled with solid carbon dioxide, to achieve
Prepare the necessary volume of Solution by dissolv-
a temperature below - 60 “C.
ing the appropriate quantity (8 g/dm3) of ammonium
peroxodisulfate in concentrated sulfuric acid (98 % To obtain quickly a cooling bath at the correct tem-
minimum purity). perature, introduce approximately 1 kg of solid carbon
dioxide into a 3-dm3 beaker and slowly pour in
CAUTION - Sulfuric acid and ammonium acetone. Transfer the cooled acetone into the Dewar
peroxodisulfate are strong oxidizing agents and flask containing approximately 200 g of solid carbon
therefore contact with organic materials should dioxide. Repeat the Operation until the desired volume
be avoided. Wear goggles, gloves and safety
is obtained.
apron, all made from appropriate materials, dur-
NOTE 2 Such a bath tan maintain a temperature below
ing all handling operations.
- 60 “C for several hours.
5.3 Solid carbon dioxide, for the cooling bath.
6.6 Thermometer, capable of measuring a tem-
containing
5.4 Dichlo romethane, analytical grade,
perature of - 60 “C + 1 “C.
-
poration at
less than 4 mg/kg oily residue after eva
105 “C.
6.7 Sampling lines, stainless steel, conforming to
NOTE 1 If the use of dichloromethane poses Problems in
the specification given in 6.4. The capacity of the
terms of health and any regulations, it may be possible to
sampling unit (filter, cooling coil, lines) shall be less
replace it by pentane of the Same quality (containing less
than 25 cm3.
than 4 mg/kg of residues at 105 “C). In this case the pro-
cedure is unchanged.
6.8 Needle valves
CAUTION - Dichloromethane is an irritant and
poses risks to health if handled incorrectly. Extract
6.8.1 One stainless steel spindle-needle valve with
under a fume
the vapours while working
3-mm fittings, permitting regulation of the flow
cupboard.
(equipment of chromatographic quality) (see
annex A, reference [4]).
55 . Laboratory detergent, see annex A, reference
.
t-a
6.8.2 One stainless steel V-needle valve with 3-mm
5.6 Water, conforming to grade 3 of ISO 3696.
fittings (see annex A, reference [4]).
6 Apparatus
6.9 Beaker, glass, graduated, of capacity 5 dm3,
shallow form.
6.1 Sample cylinder, stainless steel, fitted with two
stainless steel valves, the upper one fitted with a dip
tube, maximum Service pressure 3 MPa, minimum
6.10 Water bath, comprising a metal tank measur-
capacity 3,75 dm3, containing the LPG whose oily
ing approximately 300 mm x 300 mm x 300 mm,
residues are to be determined. with water inlet and outlet, capable of being main-
tained at a temperature of 15 “C + 5 “C; or a steam
6.2 In-line filter stainless steel, for high bath fitted with an orifice of diameter between
suppm
ex A, refe rence Cl]). 58 mm and 62 mm.
pressure (see ann
6.3 Filter discs, plain white membrane, diameter
6.11 Rotary evaporator, any model enabling the
47 mm, made of a blend of cellulose esters, nominal
evaporation of at least 200 cm3 of solvent, over a bath
pore dimension 0,8 Pm (see annex A, reference [2]).
of softened water regulated at 65 “C + 5 “C, from a
ground-necked evaporation flask.
6.4 Cooling coil, stainless steel, made by coiling
5 m of tube of external diameter 3 mm and internal
NOTE 3 A double-coil water condenser may suffice for
diameter 2 mm onto a mandrel of diameter approxi-
apparatus located in a fume cupboard; otherwise, a solid
mately 50 mm and fitted with the necessary con- carbon dioxidelacetone coolant is necessary (see annex A,
reference [SI).
nections (see annex A, reference [3]).
0 ISO ISO 13757:1996(E)
by inverting the flask for approximately 10 s or by
200-cm’ glass round-
6.12 Evaporation flask,
blowing nitrogen into it. Place the flask, fitted with its
bottom flask with a ground neck and fitted with a
stopper, and the rest of the glassware in a desiccator
glass stopper, tare less than 130 g (including stopper).
(6.16) for at least 2 h before use (take care that the
stopper does not become Stuck during cooling).
6.13 Oven, capable of maintaining a temperature of
105 “C + 5 “C.
-
If the glassware is not clean enough, or in case of
dispute or when abnormal results have been ob-
6.14 Balances
tained, clean the glassware as described in 7.1, using
gloves, having first removed any organic products by
6.14.1 For the Sample cylinder, balance with a range
rinsing with dichloromethane (5.4) followed by
accurate to within rf: 1 g or
of 10 kg minimum,
acetone (5.1).
better.
After cleaning the apparatus, carry out the tare by
6.14.2 For the evaporation flask, balance with a
weighing the evaporation flask (with stopper) to the
accurate to within
range of 160 g minimum,
nearest 0,l mg after having uns
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