ASTM D3241-98
(Test Method)Standard Test Method for Thermal Oxidation Stability of Aviation Turbine Fuels (JFTOT Procedure)
Standard Test Method for Thermal Oxidation Stability of Aviation Turbine Fuels (JFTOT Procedure)
SCOPE
1.1 This test method covers the procedure for rating the tendencies of gas turbine fuels to deposit decomposition products within the fuel system.
1.2 The values stated in SI units are to be regarded as the standard. The inch-pound values given in parentheses are for information only. The differential pressure values in mm Hg are defined only in terms of this test method.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It 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. For specific hazard statements, see 6.1.1, 7.2, 7.2.1, 7.3, 11.1.1, and Annex A3.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 3241 – 98 An American National Standard
Designation 323/99
Standard Test Method for
Thermal Oxidation Stability of Aviation Turbine Fuels
(JFTOT Procedure)
This standard is issued under the fixed designation D 3241; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This test method has been approved by the sponsoring committee and accepted by the cooperating organizations in accordance with
established procedures.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 3. Terminology
1.1 This test method covers the procedure for rating the 3.1 Definitions of Terms Specific to This Standard:
tendencies of gas turbine fuels to deposit decomposition 3.1.1 deposits—oxidative products laid down on the test
products within the fuel system. area of the heater tube or caught in the test filter, or both.
1.2 The values stated in SI units are to be regarded as the 3.1.1.1 Discussion—Fuel deposits will tend to predominate
standard. The inch-pound values given in parentheses are for at the hottest portion of the heater tube which is between the 30
information only. The differential pressure values in mm Hg mm and 50 mm position.
are defined only in terms of this test method. 3.1.2 heater tube—an aluminum coupon controlled at el-
1.3 This standard does not purport to address all of the evated temperature, over which the test fuel is pumped.
safety concerns, if any, associated with its use. It is the 3.1.2.1 Discussion—The tube is resistively heated and con-
responsibility of the user of this standard to establish appro- trolled in temperature by a thermocouple positioned inside.
priate safety and health practices and determine the applica- The critical test area is the thinner portion, 60 mm in length,
bility of regulatory limitations prior to use. For specific hazard between the shoulders of the tube. Fuel inlet to the tube is at the
statements, see Note 1, Note 2, Note 3, Note 7 and Annex A2. 0 mm position, and fuel exit is at 60 mm.
3.2 Abbreviation:
2. Referenced Documents
3.2.1 D P—differential pressure.
2.1 ASTM Standards:
4. Summary of Test Method
D 1655 Specification for Aviation Turbine Fuels
D 4306 Practice for Aviation Fuel Sample Containers for 4.1 This test method for measuring the high temperature
Tests Affected by Trace Contamination stability of gas turbine fuels uses the Jet Fuel Thermal
E 128 Test Method for Maximum Pore Diameter and Per- Oxidation Tester (JFTOT) that subjects the test fuel to condi-
meability of Rigid Porous Filters for Laboratory Use tions that can be related to those occurring in gas turbine
E 177 Practice for Use of the Terms Precision and Bias in engine fuel systems. The fuel is pumped at a fixed volumetric
ASTM Test Methods flow rate through a heater after which it enters a precision
E 691 Practice for Conducting an Interlaboratory Study to stainless steel filter where fuel degradation products may
Determine the Precision of a Test Method become trapped.
2.2 ASTM Adjuncts: 4.1.1 The apparatus uses 450 mL of test fuel ideally during
Color Standard for Tube Deposit Rating a 2.5 h test. The essential data derived are the amount of
deposits on an aluminum heater tube, and the rate of plugging
of a 17 μ nominal porosity precision filter located just
This test method is under the jurisdiction of ASTM Committee D02 on
downstream of the heater tube.
Petroleum Products and Lubricantsand is the direct responsibility of Subcommittee
D02.Jon Aviation Fuels.
5. Significance and Use
Current edition approved Dec. 10, 1998. Published February 1999. Originally
published as D 3241 – 73 T. Last previous edition D 3241 – 97.
5.1 The test results are indicative of fuel performance
Annual Book of ASTM Standards, Vol 05.01.
3 during gas turbine operation and can be used to assess the level
Annual Book of ASTM Standards, Vol 05.02.
Annual Book of ASTM Standards, Vol 14.02. of deposits that form when liquid fuel contacts a heated surface
Available from ASTM Headquarters. Order Adjunct No. ADJD3241.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 3241
TABLE 2 Critical Operating Characteristics of JFTOT
that is at a specified temperature.
Instruments
6. Apparatus
Item Definition
6.1 Jet Fuel Thermal Oxidation Tester (JFTOT)—Five
Test apparatus tube-in-shell heat exchanger as illustrated in Fig. 1.
Test coupons
models of suitable equipment may be used as indicated in
Heater tube specially fabricated aluminum tube that produces
Table 1.
controlled heated test surface; new one for each test
6.1.1 Portions of this test may be automated. Refer to the
Test filter nominal 17 μm stainless steel mesh filter element to
trap deposits; new one for each test
appropriate user manual for the model JFTOT to be used for a
Instrument parameters
description of detailed procedure. A manual is provided with
Sample volume 600 mL of sample is aerated, then this aerated fuel is
each test rig, and the latest version of each manual is on file at
used to fill the reservoir leaving space for the piston;
450 6 45 mL may be pumped in a valid test
ASTM as a Research Report. See Table 1.
Aeration rate 1.5 L/min dry air through sparger
Flow during test 3.0 6 10 % mL/min (2.7 min to 3.3 max)
NOTE 1—Caution: No attempt should be made to operate the JFTOT
Pump mechanism positive displacement, gear or piston syringe
without first becoming acquainted with all components and the function of
Cooling bus bars fluid cooled to maintain consistent tube
each.
temperature profile
Thermocouple (TC) Type J, fibre braid or Iconel sheathed
6.1.2 Certain operational parameters used with the JFTOT
Operating pressure
instrument are critically important to achieve consistent and
System 3.45 MPa 6 10 % on sample by pressurized inert
correct results. These are listed in Table 2.
gas (nitrogen) or by hydraulically transmitted force
against control valve outlet restriction
6.2 Heater Tube Deposit Rating Apparatus:
At test filter differential pressure (DP) measured across test filter
6.2.1 Visual Tube Rater, the tuberator described in Annex
(by mercury manometer or by electronic transducer)
A1. in mm Hg
Operating temperature
7. Reagents and Materials For test as stated in specification for fuel
Uniformity of run maximum deviation of 62°C from specified
7.1 Use distilled (preferred) or deionized water in the spent
temperature
sample reservoir as required for Model 230 and 240 JFTOTs. Calibration pure tin at 232°C (and for Models 230 and 240 only,
pure lead at 327°C for high point and ice + water for
7.2 Use methyl pentane, 2,2,4 trimethylpentane or
low point reference)
n-heptane (technical grade, 95 mol % minimum purity) as
general cleaning solvent. This solvent will effectively clean
internal metal surfaces of apparatus before a test, especially
those surfaces (before the test section) that contact fresh
sample.
NOTE 2—Warning: Extremely flammable. Harmful if inhaled (see
Annex A3).
7.2.1 Use trisolvent (equal mix of acetone ( 1), toluene, (2)
isopropanol ( 3)) as a specific solvent to clean internal
(working) surface of test section only.
NOTE 3—Warning: (1) Extremely flammable, vapors may cause flash
fire; (2) and (3) Flammable. Vapors of all three harmful. Irritating to skin,
eyes and mucous membranes.
FIG. 1 Standard Heater Section, Essential to All JFTOT
7.3 Use dry calcium sulfate + cobalt chloride granules
Instruments
(97 + 3 mix) in the aeration dryer. This granular material
changes gradually from blue to pink color indicating absorp-
NOTE 4—Warning: Do not inhale dust or ingest. May cause stomach
tion of water.
disorder.
Originally supplied with apparatus and available from ALCOR Petroleum
8. Standard Operating Conditions
Instruments, Inc., Box 792222, San Antonio, TX 78279-2222. Now available from
ASTM as a research report. See Table 1.
8.1 Standard conditions of the test method are as follows:
8.1.1 Fuel Quantity, 450-mL minimum for test + about 50
TABLE 1 Models of JFTOT mL for system.
8.1.2 Fuel Pre-treatment—Filtration through a single layer
JFTOT User Pressurize Pump
Differential Pressure By
Model Manual With Principle
of general purpose, retentive, qualitative filter paper followed
A
202 202/203 nitrogen gear Hg Manometer; No Record
by a 6-min aeration at 1.5 L/min air flow rate for a maximum
A
203 202/203 nitrogen gear Manometer + Graphical
of 600 mL sample using sparge stone of porosity C (see Test
Record
B
Method E 128).
215 215 nitrogen gear Transducer + Printed
Record
8.1.3 Fuel System Pressure, 3.45 MPa (500 psi) 610 %
C
230 230/240 hydraulic syringe Transducer + Printout
gage.
C
240 230/240 hydraulic syringe Transducer + Printout
8.1.4 Thermocouple Position,at39mm.
A
Available from ASTM Headquarters. Request RR:D02-1395.
B 8.1.5 Fuel System Prefilter Element, filter paper of 0.45 μm
Available from ASTM Headquarters. Request RR:D02-1396.
C
Available from ASTM Headquarters. Request RR:D02-1397. pore size.
D 3241
8.1.6 Heater Tube Control Temperature, preset as specified 10.1.2 Differential Pressure Cell—Standardize once a year
in applicable specification. or when installing a new cell (see Annex A2.2.6).
8.1.7 Fuel Flow Rate, 2.7 to 3.3 mL/min, or 20 drops of fuel 10.1.3 Aeration Dryer—Check at least monthly and change
in 9.0 6 1.0 s. if color indicates significant absorption of water (see 7.3).
8.1.8 Minimum Fuel Pumped During Test, 405 mL. 10.1.4 Metering Pump—Perform two checks of flow rate
8.1.9 Test Duration, 150 6 2 min. for each test as described in the Procedure section.
8.1.10 Cooling Fluid Flow, approximately 39 L/h, or center 10.1.5 Filter Bypass Valve—For Models 202, 203, and
of green range on cooling fluid meter. 215—check for leakage at least once a year (see Appendix X5
8.1.11 Power Setting, approximately 75 to 100 on non- ).
computer models; internally set for computer models.
11. Procedure
9. Preparation of Apparatus
11.1 Preparation of Fuel Test Sample:
9.1 Cleaning and Assembly of Heater Test Section: 11.1.1 Filter and aerate sample using standard operating
9.1.1 Clean the inside surface of the heater test section using conditions (see Annex A2.2.8).
a nylon brush saturated with trisolvent material to remove all
NOTE 7—Before operating see Caution under Note 1.
deposits.
NOTE 8—Test method results are known to be sensitive to trace
9.1.2 Check the heater tube to be used in the test for surface
contamination from sampling containers. For recommended containers,
defects and straightness by referring to the procedure in Annex
refer to Practice D 4306.
NOTE 9—Warning: All jet fuels must be considered flammable except
A1.10. Be careful, also, to avoid scratching tube shoulder
JP5 and JP7. Vapors are harmful (see Annex A3.3, Annex A3.6, and Annex
during the examination since the tube shoulder must be smooth
A3.7).
to ensure a seal under the flow conditions of the test.
11.1.2 Maintain temperature of sample between 15°C and
9.1.3 Assemble the heater section using new items: (1)
32°C during aeration. Put reservoir containing sample into hot
visually checked heater tube, (2) test filter and (3) three
or cold water bath to change temperature, if necessary.
O-rings. Inspect insulators to be sure they are undamaged.
11.1.3 Allow no more than1hto elapse between the end of
NOTE 5—Heater tubes must not be reused. Tests indicate that magne-
aeration and the start of the heating of the sample.
sium migrates to the heater tube surface under normal test conditions.
11.2 Final Assembly:
Surface magnesium may reduce adhesion of deposits to reused heater
11.2.1 Assemble the reservoir section (see User Manual).
tube.
11.2.2 Install reservoir and connect lines appropriate to the
9.1.4 During assembly of heater section, handle tube care-
model JFTOT being used (see User Manual).
fully so as not to touch center part of tube. IF CENTER OF
11.2.3 Remove protective cap and connect fuel outlet line to
HEATER TUBE IS TOUCHED, REJECT THE TUBE SINCE
heater section. Do this quickly to minimize loss of fuel.
THE CONTAMINATED SURFACE MAY AFFECT THE
11.2.4 Check all lines to ensure tightness.
DEPOSIT FORMING CHARACTERISTICS OF THE TUBE.
11.2.5 Recheck thermocouple position at 39 mm.
9.2 Cleaning and Assembly of Remainder of Test Compo-
11.2.6 Make sure drip receiver is empty (Models 230 and
nents:
240 only).
9.2.1 Perform the following steps in the order shown prior
11.3 Power Up and Pressurization:
to running a subsequent test.
11.3.1 Turn POWER to ON.
NOTE 6—It is assumed apparatus has been disassembled from previous
11.3.2 Energize the DP alarms on models with manual alarm
test (see Annex or appropriate user manual for assembly/disassembly
switch (Models 202, 203, and 215).
details).
11.3.3 Pressurize the system slowly to about 3.45 MPa as
9.2.2 Inspect and clean components that contact test sample
directed in the User Manuals for Models 202, 203, and 215 (see
and replace any seals that are faulty or suspect especially the:
also Annex A2.2.5).
(1) lip seal on piston, and (2) O-rings on the reservoir cover,
11.3.4 Inspect the system for leaks. Depressurize the system
lines, and prefilter cover.
as necessary to tighten any leaking fittings.
9.2.3 Install prepared heater section (as described in 9.1.1
11.3.5 Set controls to the standard operating conditions.
through 9.1.4).
11.3.6 Use a heater tube control temperature as specified for
9.2.4 Assemble pre-filter with new element and install.
the fuel being tested. Apply any thermocouple correction from
9.2.5 Check thermocouple for correct reference position,
the most recent calibration (see Annex A2.2.7).
then lower into standard operating position.
NOTE 10—The JFTOT can be run to a maximum tube temperature of
9.2.6 On Models 230 and 240 make sure the water beaker is
about 350°C. The temperature at which the test should be run, and the
empty.
criteria for judging results are normally embodied in fuel specifications.
10. Calibration and Standardization Procedure
11.4 Start Up:
10.1 Perform checks of key components at the frequency 11.4.1 Use procedure for each model as described in the
indicated in the following (see Annexes or user manual for appropriate User Manual.
details). 11.4.2 Some JFTOT models may do the following steps
10.1.1 Thermocouple—Calibrate a thermocouple when first automatically, but verify that:
installed and then normally every 30 to 50 tests thereafter, but 11.4.2.1 No more than 1 h maximum elapses from aeration
at least every 6 months (see Annex A2.2.8). to start of heating.
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