EN ISO 6246:1997
(Main)Petroleum products - Gum content of light and middle distillate fuels - Jet evaporation method (ISO 6246:1995)
Petroleum products - Gum content of light and middle distillate fuels - Jet evaporation method (ISO 6246:1995)
Method for the determination of the gum content (residue on evaporation) of aviation fuels and motor gasolines or other volatile distillates in their finished form. For motor gasolines a procedure for the determination of the heptane-insoluble portion of the residue is also described. Cancels and replaces the first edition, which has been technically revised.
Mineralölerzeugnisse - Abdampfrückstand von leichtflüchtigen und Mitteldestillat-Kraftstoffen - Aufblaseverfahren (ISO 6246:1995)
Diese Internationale Norm beschreibt ein Verfahren zur Bestimmung des vorhandenen Abdampfrückstandes von Flugkraftstoffen und des Abdampfrückstandes von Ottokraftstoffen oder anderen leicht flüchtigen Destillaten als Endprodukte zum Zeitpunkt der Prüfung. Für andere als Flugkraftstoffes wird auch ein Verfahren zur Bestimmung des heptanunlöslichen Anteiles des Rückstandes beschrieben.
Produits pétroliers - Teneur en gommes des distillats légers et moyens - Méthode d'évaporation au jet (ISO 6246:1995)
Naftni proizvodi - Vsebnost smolnega ostanka v lahkih in srednjih destilatnih gorivih - Metoda s prepihavanjem (ISO 6246:1995)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-maj-1998
1DGRPHãþD
SIST EN 26246:1998
SIST EN 5:1996
Naftni proizvodi - Vsebnost smolnega ostanka v lahkih in srednjih destilatnih
gorivih - Metoda s prepihavanjem (ISO 6246:1995)
Petroleum products - Gum content of light and middle distillate fuels - Jet evaporation
method (ISO 6246:1995)
Mineralölerzeugnisse - Abdampfrückstand von leichtflüchtigen und Mitteldestillat-
Kraftstoffen - Aufblaseverfahren (ISO 6246:1995)
Produits pétroliers - Teneur en gommes des distillats légers et moyens - Méthode
d'évaporation au jet (ISO 6246:1995)
Ta slovenski standard je istoveten z: EN ISO 6246:1997
ICS:
75.160.20 7HNRþDJRULYD Liquid fuels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
INTERNATIONAL
ISO
STANDARD 6246
Second edition
1995-08-15
Petroleum products - Gum content of
light and middle distillate fuels - Jet
evaporation method
Produits petroliers - Teneur en gommes des distilla ts Egers et
moyens - Methode d ’&aporation au jet
Reference number
ISO 6246:1995(E)
ISO 6246:1995(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 6246 was prepared by Technical Committee
ISO/TC 28, Petroleum products and lubrican ts.
This second edition cancels and replaces the first edition
(ISO 6246:1981), which has been technically revised.
Annex A forms an integral part of this International Standard.
0 ISO 1995
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.
I nternationa l Organization for Standardization
Case Pastal e 56 l CH-121 1 Geneve 20 l Swi tzerland
Printed in Switzerland
INTERNATIONAL STANDARD 0 ISO ISO 6246: 1995(E)
Petroleum products - Gum content of light and
middle distillate fuels - Jet evaporation method
- The use of this International Standard may involve hazardous materials, operations
WARNING
and equipment. This 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 limitations Prior to use.
higher boiling oils or particulate matter and generally reflect
1 Scope
poor handling practices in distribution downstream of the
refinery.
This International Standardspecifies a method for the
determination of the existent gum content of aviation
2 Normative references
fuels, and the gum content of motor gasolines or
other volatile distillates in their finished form, and at
The following Standards contain provisions which,
the time of test.
through reference in this text, constitute provisions
of this International Standard. At the time of publi-
For non-aviation fuels, a procedure for the determi-
cation, the editions indicated were valid. All Standards
nation of the heptane-insoluble Portion of the residue
are subject to revision, and Parties to agreements
is also described.
based on this International Standard are encouraged
to investigate the possibility of applying the most re-
CAUTION - This method is not intended for the
cent editions of the Standards indicated below.
testing of gasoline components, particularly those
Members of IEC and ISO maintain registers of cur-
with a high percentage of low-boiling unsaturated
rently valid International Standards.
compounds, as they may Cause explosions during
evaporation.
ISO 3170:1988,
Petroleum liquids - Manual
sampling.
NOTE 1 The true significance of this test method for de-
termining gum in motor gasoline is not firmly established.
lt has been proved that high gum content tan Cause ISO 3171 :1988, Petroleum liquids - Automatic pipe-
induction-System deposits and sticking of intake valves, and
line sampling.
in most instances it tan be assumed that low gum content
will ensure absence of induction-System difficulties. The
ISO 3696: 1987, Water for analytical laboratory use -
user should, however, realize that the test is not of itself
Specifica tion and test methods.
torrelative to induction-System deposits. The primary pur-
pose of the test, as applied to motor gasoline, is the meas-
ISO 4788:1980, Laboratory glassware - Graduated
urement of the Oxidation products formed in the Sample
measuring cylinders.
Prior to or during the comparatively mild conditions of the
test procedure. Since many motor gasolines are purposely
ISO 6353-2: 1983, Reagents for chemica
I analysis -
blended with non-volatile oils or additives, the heptane ex-
Part 2: Specifica tions - First series.
traction step is necessary to remove these from the evap-
oration residue so that the deleterious material, gum, may
ISO 6353-3: 1987, ßeagents for chemica
be determined. With respect to aviation turbine fuels, large I analysis -
quantities of gum are indicative of contamination of fuel by Part 3: Specifications - Second series.
0 ISO
ISO 6246: 1995(E)
3 Definitions 6 Apparatus
For the purposes of this International Standard, the
6.1 Balance, capable of weighing to an accuracy of
g definitions a
followin
PPM 0,l mg.
3.1 existent gum: Evaporation residue of aviation
6.2 Beakers, 100 ml of capacity, tall form, as illus-
fuels, without any further treatment.
trated in figure 1, individually permanently marked.
3.2 evaporation residue: Material that remains af-
NOTE 2 It is expedient to arrange the beakers in Sets, the
ter controlled heating under a flow or air or steam. number in each set being the number of beaker wells in the
evaporating bath. The lowest-mass beaker in each set
should be reserved for use as the tare.
3.3 gum content, unwashed (non-aviation f uel):
Evaporation residue of the product under test, without
6.3 Cooling vessel, tightly covered, for cooling the
any further treatment.
beakers before weighing.
3.4 gum content, solvent-washed (non-aviation
NOTE 3 If a desiccator is used, a drying agent is not re-
fuel): Residue remaining after the evaporation residue
commended.
has been washed. with heptane and the washings
discarded.
6.4 Evaporation bath, either a solid metal block
bath or a liquid bath, electrically heated and con-
structed in accordance with the general principles
shown in figure 1, having wells and jets for two or
4 Principle
more bea kers.
A measured test Portion of fuel is evaporated under
The rate of air/steam flow at the temperature of test
controlled conditions of temperature and flow of air
from each outlet jet when fitted with the conical
or steam. The resulting residue is weighed, and may
adaptors shall be 1 000 ml/s & 150 ml/s. A liquid
be subject to further treatment by solvent washing
bath, if used, shall be filled to within 25 mm of the top
and further weighing.
with a suitable liquid. Maintain the bath temperature
either by means of thermostatic controls or by reflux-
ing liquid of suitable composition.
6.5 Flow indicator, capable of indicating a total flow
5 Reagents and materials
of air or steam equivalent to 1 000 ml/s for each out-
let jet.
During the analysis, unless otherwise stated, use only
reagents specified in ISO 6353-2 and ISO 6353-3 if
6.6 Sintered glass filter funnel, capacity 150 ml,
listed there; if not, use reagents of recognized ana-
with a maximum pore diameter between 150 Fm and
lytical grade. Water where specified, shall be of a
250 Pm.
quality equivalent to grade 3 of ISO 3696.
6.7 Steam superheater, gas-fired or electrically
5.1 Heptane, CH$CH&CH3-
heated, capable of delivering to the bath inlet the re-
quired amount of steam at 232 “C + 3 “C.
-
5.2 Toluene, C&i&t+.
6.8 Two thermometers, conforming to the require-
5.3 Acetone, CH3COCH3.
ments in annex A.
5.4 Gum solvent, a mixture of equal volumes of
6.9 Graduated cylinders, capacity 50 ml or 100 ml
toluene (5.2) and acetone (5.3).
and 2 litres, conforming to the requirements of
ISO 4788.
5.5 Air supply, filtered, at a gauge pressure of not
greater than 34,5 kPa.
6.10 Forceps, stainless steel, spade-ended.
oily residue and at a 6.11 Oven, capable of being maintained at 150 “C
56 . Steam supply, free of
kPa . + 2 “C.
pressure of not less than 34,5 -
ISO 6246: 1995(E)
Dimensions in millimetres
2:
dd
-
iii-,
z3 '
EL
0 aJ
d
t
L
aJ L
t
-
.- Y
rc
d
ii
d
v:
d
cn
t
ö
z
:
T
d
L
t
Cu
tr
Figure 1 -
Apparatus for determining gum content by jet evaporation
0 ISO
ISO 6246:1995(E)
in mass represents the amou nt of steam condensed.
7 Assembly of air-jet apparatus
Calculate the steam flowrate, S, as follow s:
7.1 Assemble the air-jet apparatus as shown in fig-
S = (% - m,) 1 OOO/kt
ure 1. With the apparatus at room temperature, adjust
the flow of air to a rate of 600 ml/s at one of the
outlets, with the remaining conical adaptors in pos-
S is the flowrate of the steam, in millilitres
ition. Check the other outlets individually under the
per second, at 232 “C;
same conditions for uniform air flowrate within the
range of 600 ml/s + 90 ml/s.
is the mass, in grams, of the cylinder with
mo
the condensed steam;
NOTE 4 A total reading on a flow indicator (calibrated
under ambient conditions) corresponding to 600 ml/s
is the mass, in grams, of the cylinder and
& 90 ml/s at each outlet will ensure a flowrate of
ice;
1 000 ml/s + 150 ml/s at a temperature of 155 “C + 5 “C,
provided th; the pressure at the outlet of the flow indicator
k is the mass (0,434 g) of 1 000 ml of steam
is not greater than 34,5 kPa.
at 232 “C at atmospheric pressure;
7.2 In Order to set the apparatus in Operation, heat
t is the condensi ng time, in seconds.
the bath until the temperature reaches 162 “C, and
then introduce air into the apparatus until the reading
8.4 Adjust the apparatus to give a steam flowrate
established in accordance with 7.1 is obtained on the
of 1 000 ml/s for the outlet under test. Check the re-
flow indicator. Measure the temperature in each well
maining outlets for uniform steam flow. Make
with the thermometer (6.8) placed with the bulb rest-
necessary changes to individual outlets if the rate
ing on the bottom of a beaker (6.2) in the weil. DO not
varies by more than 150 ml of steam per second, re-
use any well having a temperature that differs from
cord the flowmeter reading and use this setting for
155 “C by more than 5 “C for Standard tests.
subsequent testing.
8 Assembly of steam-jet apparatus
9 Samples and sampling
8.1 Assemble the steam-jet apparatus as shown in
Samples for testing by the procedures described in
figure Ie
this International Standard shall be taken by the pro-
cedure described in ISO 3170, ISO 3171 or an equiv-
alent national Standard.
8.2 In Order to set the apparatus in Operation, heat
the bath until the temperature reaches 232 “C. Oper-
ate the superheater, and slowly admit dry steam into
10 Procedure
until a flowrate of 1 000 ml/s
the apparatus
+ 150 ml/s per outlet is obtained. Regulate the tem-
10.1 Wash the beakers (6.2) including the tare, with
persture of the bath within the range 239 “C + - 7 “C
the gum solvent (5.4) until free of gum. Rinse thor-
and that of the superheater to provide a well tem-
oughly with water and immerse in detergent cleaning
perature of 232 “C + 3 “C. Measure the temperature
-
Solution. The type of detergent and conditions for its
with the thermometer (6.8) placed with the bulb rest-
use shall be established in each laboratory. The crite-
ing on the bottom of a beaker (6.2) in the weil. DO not
rion for satisfactory cleaning shall be a matthing of
use any weil having a temperature that differs from
the quality of that obtained with chromic acid cleaning
232 “C by more than 3 “C for Standard tests.
Solution on used beakers (fresh chromic acid, 6 h
soaking period, rinsing with water and drying). Re-
8.3 Calibrate the flowmeter by successively con-
move the beakers from the cleaning Solution by
densing the steam flow from each outlet and weigh-
means of forceps (6.10) and handle only with forceps
ing the total quantity of water recovered. To
thereafter. Wash the beakers thoroughly, first with tap
accomplish this, attach a topper tube to a steam out-
water and then with grade 3 water, and dry in the
let jet and extend the tube into a 2 litre cylinder (6.9)
oven (6.11), controlled at 150 “C, for at least 1 h. Cool
that has been filled with crushed ice and then
the beakers for at least 2 h in the cooling vessel (6.3)
weighed. Exhaust the steam into the cylinder for ap-
placed in the vicinity of the balance (6.1).
proximately 60 s. Adjust the Position of the cylinder
so that the end of the topper tube is immersed in the
NOTE 5 For the comparison of cleaning efficiency, visual
water to a depth of less than 50 mm to prevent ex-
appearance and loss in mass on heating the glassware un-
cessive back-pressure. Weigh the cylinder. The gain der test conditions may be used. Detergent cleaning avoids
...
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