ASTM D4418-22

Standard Practice for Receipt, Storage, and Handling of Fuels for Gas Turbines

SIGNIFICANCE AND USE
5.1 This practice provides the user of gas turbine fuel oils and the designer of gas turbine fuel systems with an appreciation of the effects of fuel contaminants and general methods of controlling such contaminants in gas turbine fuel systems.  
5.2 This practice is general in nature and should not be considered a substitute for any requirement imposed by warranty of the gas turbine manufacturer, or by federal, state, or local government regulations.  
5.3 Although it cannot replace a knowledge of local conditions or the use of good engineering and scientific judgment, this practice does provide guidance in development of individual fuel management systems for the gas turbine user.
SCOPE
1.1 This practice covers the receipt, storage, and handling of fuels for gas turbines, except for gas turbines used in aircraft. It is intended to provide guidance for the control of substances in a fuel that could cause deterioration of either the fuel system, or the gas turbine, or both.  
1.2 This practice provides no guidance for either the selection of a grade of fuel, a topic covered by Specification D2880, or for the safety aspects of the fuel and fuel systems. For example, this practice does not address the spacings of storage tanks, loading and unloading facilities, etc., and procedures for dealing with the flammability and toxic properties of the fuels.  
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Oct-2022
• ICS: 75.160.20 - Liquid fuels
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.E0 - Burner, Diesel and Non-Aviation Gas Turbine Fuels

Relations

• Refers: ASTM D1500-24 - Standard Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)
• Effective Date: 01-Mar-2024
• Refers: ASTM D2880-18a - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 01-Oct-2018
• Refers: ASTM D2880-18 - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 01-May-2018
• Refers: ASTM D2880-15 - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 01-Jun-2015
• Refers: ASTM D2880-14a - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 01-Dec-2014
• Refers: ASTM D2880-14 - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 01-Aug-2014
• Refers: ASTM D2880-13b - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 15-Nov-2013
• Refers: ASTM D2880-13a - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 01-Aug-2013
• Refers: ASTM D2880-13 - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 01-May-2013
• Refers: ASTM D1500-12 - Standard Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)
• Effective Date: 01-Dec-2012
• Refers: ASTM D6469-12 - Standard Guide for Microbial Contamination in Fuels and Fuel Systems
• Effective Date: 01-Nov-2012
• Refers: ASTM D4057-06(2011) - Standard Practice for Manual Sampling of Petroleum and Petroleum Products
• Effective Date: 01-Jun-2011
• Refers: ASTM D6469-11 - Standard Guide for Microbial Contamination in Fuels and Fuel Systems
• Effective Date: 01-Jan-2011
• Refers: ASTM D2880-03(2010) - Standard Specification for Gas Turbine Fuel Oils
• Effective Date: 01-Oct-2010
• Refers: ASTM D2274-10 - Standard Test Method for Oxidation Stability of Distillate Fuel Oil (Accelerated Method)
• Effective Date: 01-Aug-2010

Overview

ASTM D4418-22: Standard Practice for Receipt, Storage, and Handling of Fuels for Gas Turbines provides essential guidance on the management of fuels used in gas turbines, excluding those for aviation applications. Developed by ASTM International, this practice emphasizes the identification, control, and minimization of fuel contaminants to ensure the protection and optimal performance of gas turbine systems. It serves as a practical resource for operators, designers, fuel managers, and maintenance personnel involved in the operation of gas turbines for industrial, power generation, and other applications.

Key Topics

• Fuel Contaminants: The standard discusses common fuel contaminants such as water (dissolved and free), particulate solids, metallic compounds, and microbial slimes. It highlights the sources, effects, and control measures necessary to prevent these contaminants from damaging gas turbine components.

• System Monitoring: Emphasis is placed on regular sampling, inspection, and analysis at various stages (receipt, storage, delivery to combustor) to identify and prevent the introduction of contaminants into the fuel system.

• Separation and Filtration: Describes separation technologies including mechanical filters, coalescening filter/separators, centrifuges, and electrostatic separators, as well as their maintenance requirements.

• Quality Control: Recommends systematic approaches to fuel quality control, documentation, cleaning schedules, and record-keeping to support fuel system reliability and traceability.

• Residual Fuel Handling: Offers specific guidance on receipt, storage, and chemical treatment (such as desalting and inhibitor usage) of residual-component fuels, with a focus on minimizing corrosion and deposit formation.

Applications

ASTM D4418-22 is applied across various industries utilizing stationary gas turbines, particularly for power generation, industrial processing, and district heating. Its guidance is valuable for:

• Fuel System Design: Informing design decisions to reduce contamination risks and facilitate effective maintenance and monitoring processes.
• Plant Operations: Supporting the development of standard operating procedures (SOPs) for fuel handling and storage, including sampling and maintenance schedules.
• Maintenance Planning: Establishing best practices for cleaning and replacing filters, separators, and tank systems to minimize unexpected downtime and equipment damage.
• Fuel Procurement and Acceptance: Enabling informed acceptance testing and quality assessment upon fuel delivery, ensuring only suitable fuel is introduced into critical systems.
• Long-Term Storage: Facilitating strategies for extended storage of distillate fuels with practices to mitigate degradation and contamination.
• Regulatory and Warranty Compliance: Helping users adhere to manufacturer warranties and relevant regulatory requirements concerning fuel quality and gas turbine operation.

Related Standards

• ASTM D2880: Specification for Gas Turbine Fuel Oils – covers the selection and classification of gas turbine fuel grades.
• ASTM D4057: Practice for Manual Sampling of Petroleum and Petroleum Products – provides guidance on sampling methodologies.
• ASTM D1500, D1796, D2274, D2276: Methods for determining color, water and sediment, oxidation stability, and particulate contaminants in fuels.
• ASTM D6469: Guide for Microbial Contamination in Fuels and Fuel Systems.
• Other regulatory standards: Compliance with local, federal, and manufacturer-specific requirements is advised in conjunction with ASTM D4418-22.

Practical Value

Implementing the guidance of ASTM D4418-22 promotes improved reliability, asset longevity, and operational efficiency in gas turbine installations. By systematically addressing the risks posed by fuel contaminants, the standard helps organizations reduce the likelihood of corrosion, erosion, unplanned outages, and costly repairs. Reliable fuel management based on this standard also supports optimal turbine efficiency and contributes to overall plant safety and environmental compliance.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D4418 − 22
Standard Practice for
Receipt, Storage, and Handling of Fuels for Gas Turbines
This standard is issued under the fixed designation D4418; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope* D2274 Test Method for Oxidation Stability of Distillate Fuel
Oil (Accelerated Method)
1.1 Thispracticecoversthereceipt,storage,andhandlingof
D2276 Test Method for Particulate Contaminant in Aviation
fuels for gas turbines, except for gas turbines used in aircraft.
Fuel by Line Sampling
It is intended to provide guidance for the control of substances
D2880 Specification for Gas Turbine Fuel Oils
inafuelthatcouldcausedeteriorationofeitherthefuelsystem,
D4057 Practice for Manual Sampling of Petroleum and
or the gas turbine, or both.
Petroleum Products
1.2 This practice provides no guidance for either the selec-
D6469 GuideforMicrobialContaminationinFuelsandFuel
tion of a grade of fuel, a topic covered by Specification D2880,
Systems
or for the safety aspects of the fuel and fuel systems. For
example, this practice does not address the spacings of storage
3. Terminology
tanks, loading and unloading facilities, etc., and procedures for
3.1 Definitions:
dealing with the flammability and toxic properties of the fuels.
3.1.1 dissolved water, n—water that is homogeneously dis-
1.3 The values stated in SI units are to be regarded as the
tributed on a molecular scale in a different liquid, called the
standard. The values given in parentheses are for information
solvent.
only.
3.1.1.1 Discussion—Dissolved water does not settle out of
1.4 This standard does not purport to address all of the solution, nor does it form a separate layer or haze in the
container. The amount of water dissolved in the solution
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- depends on the temperature of the solution. For most solvents
the amount of dissolved water will increase as the temperature
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. of the solution increases.
3.1.1.2 Discussion—Tall tanks may stratify on a macro-
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard- scopic scale. That is, the concentration of the water at different
ization established in the Decision on Principles for the locations in the tank may vary due to the influence of
Development of International Standards, Guides and Recom- macroscopic factors such as gravity, temperature of the addi-
mendations issued by the World Trade Organization Technical tion of a different fuel blend to the tank.
Barriers to Trade (TBT) Committee.
3.1.2 free water, n—water in excess of that soluble in the
liquid sample (fuel) at the temperature of the test and usually
2. Referenced Documents
appearing in the liquid sample (fuel) as a haze (cloudiness),
2.1 ASTM Standards:
droplets or water layer.
D1500 Test Method forASTM Color of Petroleum Products 3.1.2.1 Discussion—If free water is present at high enough
(ASTM Color Scale)
concentration, it will frequently settle out of the liquid sample
D1796 Test Method for Water and Sediment in Fuel Oils by to form a haze or separate layer in the container. If free water
the Centrifuge Method (Laboratory Procedure)
is present as very small droplets or in a biofilm it may not be
visible to the naked human eye but may still have an effect on
the liquid product.
This practice is under the jurisdiction of ASTM Committee D02 on Petroleum
3.1.3 fuel contaminant, n—material not intended to be
Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom-
mittee D02.E0 on Burner, Diesel and Non-Aviation Gas Turbine Fuels. present in a fuel, whether introduced during manufacture,
Current edition approved Nov. 1, 2022. Published November 2022. Originally
handling, distribution, or storage, that makes the fuel less
approved in 1984. Last previous edition approved in 2017 as D4418 – 17. DOI:
suitable for the intended use.
10.1520/D4418-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
3.1.3.1 Discussion—Contaminants, which can be soluble in
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
the fuel or insoluble (suspended liquid droplets or solid or
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. semi-solid particles), can be the result of improper processing
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4418 − 22
or contamination by a wide range of materials including water, ranty of the gas turbine manufacturer, or by federal, state, or
rust,airblowndust,deteriorationofinternalprotectivecoatings local government regulations.
on pipes or vessels, and products of fuel degradation and
5.3 Although it cannot replace a knowledge of local condi-
microbial growth.
tions or the use of good engineering and scientific judgment,
3.1.3.2 Discussion—Solid or semisolid contaminants can be
this practice does provide guidance in development of indi-
referred to as silt or sediment.
vidual fuel management systems for the gas turbine user.
3.1.4 fuel entering the combustor(s), n—this term is used to
designate the fuel that is actually burned in the gas turbine.
6. Significance of Contaminants
Fuel may actually be sampled at a point upstream from the
6.1 Contamination levels in the fuel entering the combus-
point of entry into the combustor(s), provided the sample is
tor(s) must be low for improved turbine life. Low contamina-
representative of the fuel actually entering the combustor(s).
tion levels in the fuel in the turbine’s in-plant fuel system are
3.1.5 metallic compounds, n—metals may be present as
required to minimize corrosion and operating problems. Pro-
metallic compounds in the fuel as a natural result of the
viding fuel of adequate cleanliness to the gas turbine combus-
composition of the crude oil and of the refining process.
tor(s) may require special actions by the user. These actions
However, unless special precautions are taken, additional
mightincludespecialtransportationarrangementswiththefuel
metallic compounds can be acquired during distribution and
supplier, particular care in on-site fuel storage and quality
storage. A commercial product pipeline may contain residues
control procedures, and establishment of on-site cleanup pro-
of lead-containing gasoline that would then be dissolved by the
cedures. Each of the four classes of contaminants defined in
gas turbine fuel. Tank trucks, railroad tankcars, barges, and
3.1.3 has its own significance to system operation.
tankers may be inadequately cleaned and contain residues of
6.1.1 Water will cause corrosion of tanks, piping, flow
past cargos.Acidic components in saline water salts in the fuel
dividers, and pumps. Corrosion or corrosion products in
may react with distribution and storage equipment.
close-tolerance devices, such as flow dividers, may cause
3.1.6 microbial slimes, n—may result when conditions are
plugging and may stop flow to the turbines. Free water is
conducive to the growth of microorganisms that are always
potentially corrosive in sulfur-containing fuels, it may be
present.The presence of free water is essential to the growth of
particularly corrosive. Free water may contain dissolved salts
many of these microorganisms that grow in tank water bottoms
that may be corrosive, and may encourage microbiological
and feed on nutrients in the water or on the hydrocarbons.
growth.
6.1.2 Particulate solids may shorten the life of fuel system
3.1.7 particulate solids, n—may enter a fuel from the air
components. Life of fuel pumps and of various close-tolerance
(suspended dirt and aerosols) or from the distribution and
devices is a function of particulate levels and size distributions
storage systems (rust, corrosion products, gasket debris, and so
in the fuel. High levels of particulates can lead to short cycle
forth).
times in the operation of filters, filter/separators, centrifuges,
4. Summary of Practice
andelectrostaticpurifiers.Sincesuchseparationdevicesdonot
remove all the particulates, certain quantities will be present in
4.1 The body of this practice defines the contaminants
the down-stream fuel.
frequently found in turbine fuel oils and discusses the sources
6.1.3 Trace metals refer both to those metals present as
and significance of such contaminants.
metallic compounds in solution and to metals present in
4.2 Annex A1 is a guide for the receipt, storage, and
particulates like rust.They are dissolved or suspended either in
handling of distillate gas turbine fuels, Grades 1-GTand 2-GT,
the fuel hydrocarbons or in free water present in the fuel. The
in accordance with Specification D2880.
significance of several individual trace metals with respect to
4.3 Annex A2 is a guide for the receipt, storage, and hot corrosion is discussed in 6.1.4 through 6.1.5. Although
handling of gas turbine fuels, Grades 3-GT and 4-GT, that lower levels of trace metals in a fuel will promote longer
contain residual components. turbineservicefromacorrosionstandpoint,thespecificationof
excessively low levels may limit the availability of the fuel or
4.4 Annex A3 is a guide for the selection and storage of
materially increase its cost. Table 1 suggests levels of trace
fuels intended for long-term storage, when such fuels are
metals that would probably yield satisfactory service.
distillate fuels.
4.5 Annex A4 is a guide for gas turbine users who are
considering the use of fuels from alternative non-petroleum
sources.
TABLE 1 Trace Metal Limits of Fuel Entering Turbine
Combustor(s)
5. Significance and Use
Trace Metal Limits by Weight, max, ppm
Designation
Sodium plus
5.1 This practice provides the user of gas turbine fuel oils
Vanadium Calcium Lead
Potassium
and the designer of gas turbine fuel systems with an apprecia-
No. 0-GT 0.5 0.5 0.5 0.5
tion of the effects of fuel contaminants and general methods of
No. 1-GT 0.5 0.5 0.5 0.5
controlling such contaminants in gas turbine fuel systems.
No. 2-GT 0.5 0.5 0.5 0.5
No. 3-GT 0.5 0.5 0.5 0.5
5.2 This practice is general in nature and should not be
No. 4-GT (Consult turbine manufacturers)
considered a substitute for any requirement imposed by war-
D4418 − 22
6.1.4 Ash is the noncombustible material in an oil. Ash or dirt, potential sources of sodium, potassium, and calcium.
forming materials may be present in fuel oil in two forms: (1) Thesearenormallyremovedatthegas-turbinesite,unlesssuch
solid particles, and (2) oil- or water-soluble metallic com-
contaminants are extremely finely divided.
pounds. The solid particles are for the most part the same
6.1.6.1 Sodium and Potassium can combine with vanadium
material that is designated as sediment in the water and
to form eutectics that melt at temperatures as low as 566 °C
sediment test. Depending on their size, these particles can
(1050 °F) and can combine with sulfur in the fuel to yield
contributetowearinthefuelsystemandtopluggingofthefuel
sulfates with melting points in the operating range of the gas
filterandthefuelnozzle.Thesolublemetalliccompoundshave
turbine. These compounds produce severe corrosion, and for
little or no effect on wear or plugging, but they can contain
turbines operating at gas inlet temperatures above 650 °C
elements that produce turbine corrosion and deposits as de-
(1200 °F), additives are not yet in general use that control such
scribed in 6.1.5.
corrosion.
6.1.5 Vanadium and Lead—Fuel contaminants might in-
6.1.6.2 Accordingly, the sodium-plus-potassium level must
clude soluble compounds such as vanadium porphyrins, me-
be limited, but each element is measured separately. Some gas
tallic soaps, or tetraethyl lead that cannot be removed from the
turbine installations incorporate systems for washing oil with
fuel at the gas-turbine site.
water to reduce the sodium-plus-potassium level. In installa-
6.1.5.1 Vanadium can form low melting compounds such as
tions where the fuel is moved by sea transport, the sodium-
vanadium pentoxide which melts at 691 °C (1275 °F), and
plus-potassium level should be checked prior to use to ensure
causes severe corrosive attack on all of the high-temperature
that the oil has not become contaminated with sea salt. For gas
alloys used for gas-turbine blades. If there is sufficient magne-
turbines operating at turbine inlet gas temperatures below
sium in the fuel, it will combine with the vanadium to form
650 °C(1200 °F),thecorrosionduetosodiumcompoundsisof
compounds with higher melting points and thus reduce the
minor importance and can be further reduced by silicon-base
corrosion rate to an acceptable level. The resulting ash will
additives. A high sodium content is even beneficial in these
form deposits in the turbine and will require appropriate
turbines because it increases the water-solubility of the depos-
cleaning procedures.
its and thereby increases the ease with which gas turbines can
6.1.5.2 When vanadium is present in more than trace
be water-washed to obtain recovery of the operating perfor-
amounts either in excess of 0.5 ppm or a level recommended
mance.
by the turbine manufacturer, it is necessary to maintain a
weight ratio of magnesium to vanadium in the fuel of not less
6.1.6.3 Calcium—Calcium is not harmful from a corrosion
than 3.0 in order to control corrosion. standpoint: in fact, it serves to inhibit the corrosive action of
6.1.5.3 An upper limit of 3.5 is suggested since larger ratios
vanadium. However, calcium can lead to hard-bonded deposits
will lead to unnecessarily high rates of ash deposition. In most
thatarenotself-spallingwhenthegasturbineisshutdown,and
cases, the required magnesium-to-vanadium ratio will be
are not readily removed by water washing of the turbine. The
obtained by additions of magnesium-containing compounds to
fuel-washing systems, used at some gas turbine installations to
thefueloil.Thespecialrequirementscoveringtheadditionand
reduce the sodium and potassium level, will also significantly
type of magnesium-containing additive, or equivalent, shall be
lower the calcium content of fuel oil.
specified by mutual agreement between the various interested
6.1.7 Microbial Slimes—Microbial slimes caused by micro-
parties. The additive will vary depending on the application,
organisms can plug filters and other close-tolerance openings.
but it is always essential that there is a fine and uniform
Someorganismscancausecorrosionaswellasproduceslimes.
dispersionoftheadditiveinthefuelatthepointofcombustion.
Under anaerobic conditions, hydrogen sulfide, which may
6.1.5.4 For gas turbines operating at turbine-inlet gas tem-
cause corrosion, can be generated by biological action. Bio-
peratures below 650 °C (1200 °F), the corrosion of the high-
cides are available for controlling the growth of
temperature alloys is of minor importance, and the use of a
microorganisms, but their effect on trace metal levels and other
silicon-base additive will further reduce the corrosion rate by
fuel properties should be considered. Since water is required
absorption and dilution of the vanadium compounds.
for the growth of the microorganisms, one way of controlling
6.1.5.5 Leadcancausecorrosion,andinadditionitcanspoil
their growth is to eliminate the presence of water through
the beneficial inhibiting effect of magnesium additives on
tank-stripping operations or other separation techniques. Refer
vanadium corrosion. Since lead is only rarely found in signifi-
to Guide D6469 for a more complete discussion.
cant quantities in crude oils, its appearance in the fuel oil is
primarily the result of contamination during processing or
7. Keywords
transportation.
6.1.6 Sodium, Potassium, and Calcium—Fuel contaminants 7.1 contaminants; fuel handling; fuel storage; gas turbine
might also include fuel-insoluble materials such as water, salt, fuels
D4418 − 22
ANNEXES
(Mandatory Information)
A1. PRACTICE FOR THE RECEIPT, STORAGE, AND HANDLING OF DISTILLATE TURBINE FUELS
A1.1 Scope separators are the various types of filters, centrifuges, and
electrostatic separators.
A1.1.1 This practice covers the receipt, storage, and han-
A1.2.2.1 filters—devices for separating suspended matter
dling of distillate gas turbine fuels, Grades 1-GT and 2-GT,
from the fuel by passing the fuel through a porous medium.
purchased in accordance with Specification D2880.
A1.2.2.2 screens—filters designed for the separation of
A1.1.2 This practice may also be used as a guideline for the
relatively coarse material from the fuel. They are commonly
receipt, storage, and handling of gas turbine fuel, Grade 0-GT,
used to remove such materials as rags, weld material, gasket
purchased in accordance with Specification D2880, but only if
pieces, and other debris from the fuel ahead of a pump, that
modifications are made to take into account the volatile nature
could be harmed if such debris were to reach the pump.
of Grade 0-GT fuel. Those modifications are not specified in
A1.2.2.3 mechanical or edge filters—filters consisting of
this practice.
stacks of metal disks separated at precise intervals by spacer
A1.1.3 This practice provides guidance in developing an
plates.Theliquidtobefilteredflowsradiallybetweenthedisks
individual fuel management system for the gas-turbine user. It
removing the particles on the edges. These filters may be
includes suggestions for the operation and maintenance of
cleaned on-line manually or automatically to remove accumu-
existing fuel storage and handling facilities, and for identifying
lated solids.
where, when, and how fuel quality should be monitored.
A1.2.2.4 cartridge filters—filters that use one or more
A1.2 Terminology
replaceable or renewable cartridges containing the filter me-
dium.Suchfiltersmayuseelementsoffiber,resin-impregnated
A1.2.1 fuel storage system—Fig. A1.1 is a generalized fuel
(often pleated) filter paper, porous stone, or porous stainless
storage system for use with distillate fuels, Grades 1-GT and
steel of controlled porosity.
2-GT, conforming to Specification D2880. It consists of the
tankage, piping, fittings, and separation equipment between the A1.2.2.5 coalescing filter/separators—usually cartridge fil-
tersthatcanremovewateraswellasparticulatesolids.Thefine
point of connection with the delivery truck, railroad car, or
other transportation equipment and the point where the fuel droplets of water in a fuel are coalesced into larger drops that
are separated by the effect of gravity. Such filters are also
enters the gas turbine combustor(s). The specific configuration
ofcomponentswillvarywiththemanufacturer’sandtheuser’s termed coalescers, separator filters, and filter/separators.
preference for one type of equipment over another, for
A1.2.2.6 depth-type filters—consist of beds of fine, some-
example, a centrifugal purifier over a coalescing filter/
times graded, solids such as sand. Sometimes clay beds are
separator. Thus, Fig.A1.1 is merely a guide for discussion and
used to provide adsorptive properties as well as filtration. Salt
illustration.
towers are a specialized class of depth filters for removal of
water.
A1.2.2 separation system—includes equipment for remov-
ing foreign materials, for example, water and solids, from A1.2.2.7 centrifuge—a rotating mechanical device for sepa-
fuels. Fuel storage tanks may serve simultaneously as rating solids from liquids and immiscible liquids from each
separators, since contaminants can settle to the bottom of such other. When used for fuel or lubricant purification, they are
tanks under the influence of gravity. Other commonly used sometimes called centrifugal purifiers or simply purifiers.
FIG. A1.1 Distillate Fuel Storage and Handling System (Gas Turbine Fuels Grades 1-GT and 2-GT)
D4418 − 22
A1.2.2.8 electrostatic separators—use electrostatic forces of acceptable quality will reach the turbine combustor(s). Brief
to separate water or solids, or both, from a liquid fuel. These and visual methods may serve to suggest the presence of some
include electric desalters that are commonly used to remove contaminants, but established fuel analysis methods including
saline water from crude petroleum oil prior to distillation. chemical analysis for trace elements are needed for more
complete judgement of fuel quality.
A1.2.3 the user’s fuel quality control system—consists of
the user’s sampling policies and procedures, associated test,
A1.6.2 The effectiveness of a fuel separation system may
and examination procedures. Use of this system establishes the
best be judged by the use of specialized analytical methods, as
conformityofthefueltopurchaseagreements,andensuresthat
recommended by the equipment suppliers or by fuel vendors.
thequalityoffuelinstorageandas-deliveredtothegas-turbine
These might include conductivity, dielectric properties, color,
combustors conforms to the necessary quality standards.
content and quality of particulates, turbidity, spectral
properties, or filterability. From such data, useful inferences
A1.3 Summary of Practice
maybederivedtosupplementmoredetailedchemicalanalysis.
A1.3.1 Sampling and inspection of the fuel should be done
A1.7 Cleaning and Maintenance
upon receipt at the user site, and periodically thereafter at
specified locations and times to identify contaminated or
A1.7.1 Arelatively long residence of fuel in tankage allows
otherwise unsatisfactory fuel before it reaches the combus-
separation of insoluble contaminants, especially water and
tor(s).
inorganicsolids.Accumulationofwatercangeneratecorrosion
product solids and biological slimes.These materials can result
A1.3.2 Fuel system components should be cleaned and
in gradual or sudden overloading of separation equipment and
maintained either periodically or on the basis of operational
possibly the erosion or plugging of close-tolerance devices
evidence (pressure drop across a filter), or on a combination of
such as fuel pumps and flow dividers.
the two.
A1.7.1.1 Water as a separate phase mobilizes oxygen and
A1.4 Significance and Use
acidity to effect corrosion or simple rusting of tank metal
surfaces, and gives a medium for biological slime develop-
A1.4.1 The use of fuel-system monitoring and quality
ment.Therateofaccumulationofwateranditsproductsinfuel
control techniques, combined with scheduled cleaning and
tank bottoms can be established by appropriate samples at
maintenance, will minimize the quantity of contaminants
point 2. A schedule of tank stripping should be established to
reaching the combustor(s) and hence will minimize corrosion
maintain water at a low level. Careful, slow drawoff rates
and erosion of gas turbine components.
enable more complete stripping.
A1.4.2 The use of fuel monitoring, storage, and handling
A1.7.1.2 Rust or other inorganic debris present in tank
techniques will limit water, suspended solids, and microbial
bottom from previous corrosion, from peeling of possible
growth in the fuel; this in turn will minimize corrosion and
protective coatings, or from tank scale deposits should be
erosion of gas turbine components.
removed by appropriate cleaning procedures to prevent down-
streamdamage.Chronicrecurrenceoftheseproblemsmaybest
A1.5 Sampling
be solved by use of special corrosion inhibitors, by incorpora-
A1.5.1 Samplesshouldbetakenateachofthefourpointsas
tion of tank linings, or by substitution of tankage with better
inFig.A1.1.ConsultPracticeD4057,forsamplingprocedures.
corrosion resistance.
A1.5.1.1 A sample should be taken at point 1, on delivery,
A1.7.2 Theroleofseparationsystemsinremovingcontami-
during transfer into the storage tank.
nants inevitably involves the fouling of such equipment with
A1.5.1.2 Fuelstoragetanksamplesshouldincludebothtank
debris. In order to sustain effective operation, proper mainte-
bottom samples and “all-level” samples. These samples shall
nance schedules for cleaning or equipment renewal must be
be taken at a frequency to be determined by the user based on
followed.
the rate of accumulation of water and other contaminants.
When the system consists of multiple tankage, take these
A1.7.2.1 The proper operation of all types of fuel filters is
samples preparatory to drawing fuel from a given tank. When reduced by fouling and accumulation of contaminants, result-
the gas turbine is used for infrequent standby or emergency
ing in reduced fuel throughout or increased pressure
service, take the sample on a closely observed schedule. differentials, or both. Operation of screens and barrier filters
may be restored by cleaning, for example, a back-flush
A1.5.1.3 Sampling at points three and four is essential to
determine the effectiveness of the separation system, if any, sequence. Some cartridge filters cannot be back-flushed and
hence must be replaced. Some coalescing filters, in addition to
and to assure the quality of the fuel being supplied to the gas
turbine. The frequency of such sampling should be determined becoming plugged, may lose their ability to shed coalesced
water droplets because of the accumulation of surfactants on
by the user’s experience and in consultation with the turbine
manufacturer. their semipermeable filter media, and also must be replaced.
A1.7.2.2 The proper functioning of both centrifugal and
A1.6 Inspection and Analysis of Samples
electrostatic separators is compromised to some degree by the
A1.6.1 Inspection and analysis of fuel is very important in accumulation of solid or semisolid debris, that makes small but
determining fuel quality at various locations and times in the important changes in internal geometry. The extent of these
fuel storage and handling system and will ensure that only fuel effects and the rate at which they occur depend on the type and
D4418 − 22
level of contamination in fuels. These malfunctions are mani- the amount, type, and quality of fuel burned in the gas turbine
fested in a reduced ability to remove water and particulate is important to trace the causes of unusual maintenance
matter (see A1.6.2). In both types of equipment, purging problems and to assess the performance of the fuel storage and
sequences for removal of such debris are possible during separation facilities. These records also serve to help the user
operation, but thorough cleaning at longer intervals is also decide what frequency of sampling and maintenance opera-
advisable to restore design efficiency. tions are required. Such a record should include the date, time,
and location of all samples, fuel source, flow rate, the record of
A1.8 Documentation
measurements and analyses performed, and pertinent informa-
A1.8.1 In view of the critical requirements for safe and tion relevant to the condition and operation of fuel tankage and
efficient operation, an adequate record to provide evidence of contaminant-separation equipment.
A2. PRACTICE FOR THE RECEIPT, STORAGE, AND HANDLING OF TURBINE FUELS CONTAINING RESIDUAL
COMPONENTS
A2.1 Scope conditions or the application of sound engineering and scien-
tific judgement, but it does provide guidance for the develop-
A2.1.1 This practice covers the receipt, storage, handling,
ment of an individual fuel-management system for the gas
and chemical treatment of gas turbine fuels, Grades 3-GT and
turbine user.
4-GT, in accordance with Specification D2880. Grade 3-GT
fuel may contain residual components, and Grade 4-GT fuel is
A2.2 Terminology
defined as one containing residual components.
A2.2.1 The general descriptions of systems to
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D4418 − 17 D4418 − 22
Standard Practice for
Receipt, Storage, and Handling of Fuels for Gas Turbines
This standard is issued under the fixed designation D4418; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This practice covers the receipt, storage, and handling of fuels for gas turbines, except for gas turbines used in aircraft. It is
intended to provide guidance for the control of substances in a fuel that could cause deterioration of either the fuel system, or the
gas turbine, or both.
1.2 This practice provides no guidance for either the selection of a grade of fuel, a topic covered by Specification D2880, or for
the safety aspects of the fuel and fuel systems. For example, this practice does not address the spacings of storage tanks, loading
and unloading facilities, etc., and procedures for dealing with the flammability and toxic properties of the fuels.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D1500 Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)
D1796 Test Method for Water and Sediment in Fuel Oils by the Centrifuge Method (Laboratory Procedure)
D2274 Test Method for Oxidation Stability of Distillate Fuel Oil (Accelerated Method)
D2276 Test Method for Particulate Contaminant in Aviation Fuel by Line Sampling
D2880 Specification for Gas Turbine Fuel Oils
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D6469 Guide for Microbial Contamination in Fuels and Fuel Systems
3. Terminology
3.1 Definitions:
3.1.1 dissolved water, n—water that is homogeneously distributed on a molecular scale in a different liquid, called the solvent.
This practice is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.E0 on Burner, Diesel and Non-Aviation Gas Turbine Fuels.
Current edition approved May 1, 2017Nov. 1, 2022. Published May 2017November 2022. Originally approved in 1984. Last previous edition approved in 20162017 as
D4418 – 00 (2016).D4418 – 17. DOI: 10.1520/D4418-17.10.1520/D4418-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4418 − 22
3.1.1.1 Discussion—
Dissolved water does not settle out of solution, nor does it form a separate layer or haze in the container. The amount of water
dissolved in the solution depends on the temperature of the solution. For most solvents the amount of dissolved water will increase
as the temperature of the solution increases.
3.1.1.2 Discussion—
Tall tanks may stratify on a macroscopic scale. That is, the concentration of the water at different locations in the tank may vary
due to the influence of macroscopic factors such as gravity, temperature of the addition of a different fuel blend to the tank.
3.1.2 fuel enteringfree water, the n—combustor(s)—this term is used to designate the fuel that is actually burned in the gas turbine.
Fuel may actually be sampled at a point upstream from the point of entry into the combustor(s), provided the sample is
representative of the fuel actually entering the combustor(s).water in excess of that soluble in the liquid sample (fuel) at the
temperature of the test and usually appearing in the liquid sample (fuel) as a haze (cloudiness), droplets or water layer.
3.1.2.1 Discussion—
If free water is present at high enough concentration, it will frequently settle out of the liquid sample to form a haze or separate
layer in the container. If free water is present as very small droplets or in a biofilm it may not be visible to the naked human eye
but may still have an effect on the liquid product.
3.1.3 fuel contaminant, n—material not intended to be present in a fuel, whether introduced during manufacture, handling,
distribution, or storage, that makes the fuel less suitable for the intended use.
3.1.3.1 Discussion—
Contaminants, which can be soluble in the fuel or insoluble (suspended liquid droplets or solid or semi-solid particles), can be the
result of improper processing or contamination by a wide range of materials including water, rust, airblown dust, deterioration of
internal protective coatings on pipes or vessels, and products of fuel degradation and microbial growth.
3.1.3.2 Discussion—
Solid or semisolid contaminants can be referred to as silt or sediment.
3.1.4 dissolved and free water,fuel entering the combustor(s), n—water may be present in the fuel as dissolved water or as “free”
(undissolved) water, or both. The free water may be fresh or saline. Fresh water may enter the fuel from steam coils in storage
tanks, from condensation out of moisture-laden air, or from leaking cooling coils. Saline water can enter the fuel during
transportation in barges or tankers.this term is used to designate the fuel that is actually burned in the gas turbine. Fuel may actually
be sampled at a point upstream from the point of entry into the combustor(s), provided the sample is representative of the fuel
actually entering the combustor(s).
3.1.4 particulate solids, n—may enter a fuel from the air (suspended dirt and aerosols) or from the distribution and storage systems
(rust, corrosion products, gasket debris, and so forth).
3.1.5 metallic compounds, n—metals may be present as metallic compounds in the fuel as a natural result of the composition of
the crude oil and of the refining process. However, unless special precautions are taken, additional metallic compounds can be
acquired during distribution and storage. A commercial product pipeline may contain residues of lead-containing gasoline that
would then be dissolved by the gas turbine fuel. Tank trucks, railroad tankcars, barges, and tankers may be inadequately cleaned
and contain residues of past cargos. Acidic components in saline water salts in the fuel may react with distribution and storage
equipment.
3.1.6 microbial slimes, n—may result when conditions are conducive to the growth of microorganisms that are always present. The
presence of free water is essential to the growth of many of these microorganisms that grow in tank water bottoms and feed on
nutrients in the water or on the hydrocarbons.
3.1.7 particulate solids, n—may enter a fuel from the air (suspended dirt and aerosols) or from the distribution and storage systems
(rust, corrosion products, gasket debris, and so forth).
4. Summary of Practice
4.1 The body of this practice defines the contaminants frequently found in turbine fuel oils and discusses the sources and
significance of such contaminants.
D4418 − 22
4.2 Annex A1 is a guide for the receipt, storage, and handling of distillate gas turbine fuels, Grades 1-GT and 2-GT, in accordance
with Specification D2880.
4.3 Annex A2 is a guide for the receipt, storage, and handling of gas turbine fuels, Grades 3-GT and 4-GT, that contain residual
components.
4.4 Annex A3 is a guide for the selection and storage of fuels intended for long-term storage, when such fuels are distillate fuels.
4.5 Annex A4 is a guide for gas turbine users who are considering the use of fuels from alternative non-petroleum sources.
5. Significance and Use
5.1 This practice provides the user of gas turbine fuel oils and the designer of gas turbine fuel systems with an appreciation of
the effects of fuel contaminants and general methods of controlling such contaminants in gas turbine fuel systems.
5.2 This practice is general in nature and should not be considered a substitute for any requirement imposed by warranty of the
gas turbine manufacturer, or by federal, state, or local government regulations.
5.3 Although it cannot replace a knowledge of local conditions or the use of good engineering and scientific judgment, this
practice does provide guidance in development of individual fuel management systems for the gas turbine user.
6. Significance of Contaminants
6.1 Contamination levels in the fuel entering the combustor(s) must be low for improved turbine life. Low contamination levels
in the fuel in the turbine’s in-plant fuel system are required to minimize corrosion and operating problems. Providing fuel of
adequate cleanliness to the gas turbine combustor(s) may require special actions by the user. These actions might include special
transportation arrangements with the fuel supplier, particular care in on-site fuel storage and quality control procedures, and
establishment of on-site cleanup procedures. Each of the four classes of contaminants defined in 3.1.23.1.3 has its own significance
to system operation.
6.1.1 Water will cause corrosion of tanks, piping, flow dividers, and pumps. Corrosion or corrosion products in close-tolerance
devices, such as flow dividers, may cause plugging and may stop flow to the turbines. Free water is potentially corrosive in
sulfur-containing fuels, it may be particularly corrosive. Free water may contain dissolved salts that may be corrosive, and may
encourage microbiological growth.
6.1.2 Particulate solids may shorten the life of fuel system components. Life of fuel pumps and of various close-tolerance devices
is a function of particulate levels and size distributions in the fuel. High levels of particulates can lead to short cycle times in the
operation of filters, filter/separators, centrifuges, and electrostatic purifiers. Since such separation devices do not remove all the
particulates, certain quantities will be present in the down-stream fuel.
6.1.3 Trace metals refer both to those metals present as metallic compounds in solution and to metals present in particulates like
rust. They are dissolved or suspended either in the fuel hydrocarbons or in free water present in the fuel. The significance of several
individual trace metals with respect to hot corrosion is discussed in 6.1.4 through 6.1.5. Although lower levels of trace metals in
a fuel will promote longer turbine service from a corrosion standpoint, the specification of excessively low levels may limit the
availability of the fuel or materially increase its cost. Table 1 suggests levels of trace metals that would probably yield satisfactory
TABLE 1 Trace Metal Limits of Fuel Entering Turbine
Combustor(s)
Trace Metal Limits by Weight, max, ppm
Designation
Sodium plus
Vanadium Calcium Lead
Potassium
No. 0-GT 0.5 0.5 0.5 0.5
No. 1-GT 0.5 0.5 0.5 0.5
No. 2-GT 0.5 0.5 0.5 0.5
No. 3-GT 0.5 0.5 0.5 0.5
No. 4-GT (Consult turbine manufacturers)
D4418 − 22
service.
6.1.4 Ash is the noncombustible material in an oil. Ash forming materials may be present in fuel oil in two forms: (1) solid
particles, and (2) oil- or water-soluble metallic compounds. The solid particles are for the most part the same material that is
designated as sediment in the water and sediment test. Depending on their size, these particles can contribute to wear in the fuel
system and to plugging of the fuel filter and the fuel nozzle. The soluble metallic compounds have little or no effect on wear or
plugging, but they can contain elements that produce turbine corrosion and deposits as described in 6.1.5.
6.1.5 Vanadium and Lead—Fuel contaminants might include soluble compounds such as vanadium porphyrins, metallic soaps, or
tetraethyl lead that cannot be removed from the fuel at the gas-turbine site.
6.1.5.1 Vanadium can form low melting compounds such as vanadium pentoxide which melts at 691 °C (1275 °F), and causes
severe corrosive attack on all of the high-temperature alloys used for gas-turbine blades. If there is sufficient magnesium in the
fuel, it will combine with the vanadium to form compounds with higher melting points and thus reduce the corrosion rate to an
acceptable level. The resulting ash will form deposits in the turbine and will require appropriate cleaning procedures.
6.1.5.2 When vanadium is present in more than trace amounts either in excess of 0.5 ppm or a level recommended by the turbine
manufacturer, it is necessary to maintain a weight ratio of magnesium to vanadium in the fuel of not less than 3.0 in order to control
corrosion.
6.1.5.3 An upper limit of 3.5 is suggested since larger ratios will lead to unnecessarily high rates of ash deposition. In most cases,
the required magnesium-to-vanadium ratio will be obtained by additions of magnesium-containing compounds to the fuel oil. The
special requirements covering the addition and type of magnesium-containing additive, or equivalent, shall be specified by mutual
agreement between the various interested parties. The additive will vary depending on the application, but it is always essential
that there is a fine and uniform dispersion of the additive in the fuel at the point of combustion.
6.1.5.4 For gas turbines operating at turbine-inlet gas temperatures below 650 °C (1200 °F), the corrosion of the high-temperature
alloys is of minor importance, and the use of a silicon-base additive will further reduce the corrosion rate by absorption and dilution
of the vanadium compounds.
6.1.5.5 Lead can cause corrosion, and in addition it can spoil the beneficial inhibiting effect of magnesium additives on vanadium
corrosion. Since lead is only rarely found in significant quantities in crude oils, its appearance in the fuel oil is primarily the result
of contamination during processing or transportation.
6.1.6 Sodium, Potassium, and Calcium—Fuel contaminants might also include fuel-insoluble materials such as water, salt, or dirt,
potential sources of sodium, potassium, and calcium. These are normally removed at the gas-turbine site, unless such contaminants
are extremely finely divided.
6.1.6.1 Sodium and Potassium can combine with vanadium to form eutectics that melt at temperatures as low as 566 °C (1050 °F)
and can combine with sulfur in the fuel to yield sulfates with melting points in the operating range of the gas turbine. These
compounds produce severe corrosion, and for turbines operating at gas inlet temperatures above 650 °C (1200 °F), additives are
not yet in general use that control such corrosion.
6.1.6.2 Accordingly, the sodium-plus-potassium level must be limited, but each element is measured separately. Some gas turbine
installations incorporate systems for washing oil with water to reduce the sodium-plus-potassium level. In installations where the
fuel is moved by sea transport, the sodium-plus-potassium level should be checked prior to use to ensure that the oil has not become
contaminated with sea salt. For gas turbines operating at turbine inlet gas temperatures below 650 °C (1200 °F), the corrosion due
to sodium compounds is of minor importance and can be further reduced by silicon-base additives. A high sodium content is even
beneficial in these turbines because it increases the water-solubility of the deposits and thereby increases the ease with which gas
turbines can be water-washed to obtain recovery of the operating performance.
6.1.6.3 Calcium—Calcium is not harmful from a corrosion standpoint: in fact, it serves to inhibit the corrosive action of vanadium.
However, calcium can lead to hard-bonded deposits that are not self-spalling when the gas turbine is shut down, and are not readily
removed by water washing of the turbine. The fuel-washing systems, used at some gas turbine installations to reduce the sodium
and potassium level, will also significantly lower the calcium content of fuel oil.
6.1.7 Microbial Slimes—Microbial slimes caused by microorganisms can plug filters and other close-tolerance openings. Some
organisms can cause corrosion as well as produce slimes. Under anaerobic conditions, hydrogen sulfide, which may cause
D4418 − 22
corrosion, can be generated by biological action. Biocides are available for controlling the growth of microorganisms, but their
effect on trace metal levels and other fuel properties should be considered. Since water is required for the growth of the
microorganisms, one way of controlling their growth is to eliminate the presence of water through tank-stripping operations or
other separation techniques. Refer to Guide D6469 for a more complete discussion.
7. Keywords
7.1 contaminants; fuel handling; fuel storage; gas turbine fuels
D4418 − 22
ANNEXES
(Mandatory Information)
A1. PRACTICE FOR THE RECEIPT, STORAGE, AND HANDLING OF DISTILLATE TURBINE FUELS
A1.1 Scope
A1.1.1 This practice covers the receipt, storage, and handling of distillate gas turbine fuels, Grades 1-GT and 2-GT, purchased in
accordance with Specification D2880.
A1.1.2 This practice may also be used as a guideline for the receipt, storage, and handling of gas turbine fuel, Grade 0-GT,
purchased in accordance with Specification D2880, but only if modifications are made to take into account the volatile nature of
Grade 0-GT fuel. Those modifications are not specified in this practice.
A1.1.3 This practice provides guidance in developing an individual fuel management system for the gas-turbine user. It includes
suggestions for the operation and maintenance of existing fuel storage and handling facilities, and for identifying where, when, and
how fuel quality should be monitored.
A1.2 Terminology
A1.2.1 fuel storage system—Fig. A1.1 is a generalized fuel storage system for use with distillate fuels, Grades 1-GT and 2-GT,
conforming to Specification D2880. It consists of the tankage, piping, fittings, and separation equipment between the point of
connection with the delivery truck, railroad car, or other transportation equipment and the point where the fuel enters the gas
turbine combustor(s). The specific configuration of components will vary with the manufacturer’s and the user’s preference for one
type of equipment over another, for example, a centrifugal purifier over a coalescing filter/separator. Thus, Fig. A1.1 is merely a
guide for discussion and illustration.
A1.2.2 separation system—includes equipment for removing foreign materials, for example, water and solids, from fuels. Fuel
storage tanks may serve simultaneously as separators, since contaminants can settle to the bottom of such tanks under the influence
of gravity. Other commonly used separators are the various types of filters, centrifuges, and electrostatic separators.
FIG. A1.1 Distillate Fuel Storage and Handling System (Gas Turbine Fuels Grades 1-GT and 2-GT)
D4418 − 22
A1.2.2.1 filters—devices for separating suspended matter from the fuel by passing the fuel through a porous medium.
A1.2.2.2 screens—filters designed for the separation of relatively coarse material from the fuel. They are commonly used to
remove such materials as rags, weld material, gasket pieces, and other debris from the fuel ahead of a pump, that could be harmed
if such debris were to reach the pump.
A1.2.2.3 mechanical or edge filters—filters consisting of stacks of metal disks separated at precise intervals by spacer plates. The
liquid to be filtered flows radially between the disks removing the particles on the edges. These filters may be cleaned on-line
manually or automatically to remove accumulated solids.
A1.2.2.4 cartridge filters—filters that use one or more replaceable or renewable cartridges containing the filter medium. Such
filters may use elements of fiber, resin-impregnated (often pleated) filter paper, porous stone, or porous stainless steel of controlled
porosity.
A1.2.2.5 coalescing filter/separators —filter/separators—usually cartridge filters that can remove water as well as particulate
solids. The fine droplets of water in a fuel are coalesced into larger drops that are separated by the effect of gravity. Such filters
are also termed coalescers, separator filters, and filter/separators.
A1.2.2.6 depth-type filters—consist of beds of fine, sometimes graded, solids such as sand. Sometimes clay beds are used to
provide adsorptive properties as well as filtration. Salt towers are a specialized class of depth filters for removal of water.
A1.2.2.7 centrifuge—a rotating mechanical device for separating solids from liquids and immiscible liquids from each other.
When used for fuel or lubricant purification, they are sometimes called centrifugal purifiers or simply purifiers.
A1.2.2.8 electrostatic separators—use electrostatic forces to separate water or solids, or both, from a liquid fuel. These include
electric desalters that are commonly used to remove saline water from crude petroleum oil prior to distillation.
A1.2.3 the user’s fuel quality control system—consists of the user’s sampling policies and procedures, associated test, and
examination procedures. Use of this system establishes the conformity of the fuel to purchase agreements, and ensures that the
quality of fuel in storage and as-delivered to the gas-turbine combustors conforms to the necessary quality standards.
A1.3 Summary of Practice
A1.3.1 Sampling and inspection of the fuel should be done upon receipt at the user site, and periodically thereafter at specified
locations and times to identify contaminated or otherwise unsatisfactory fuel before it reaches the combustor(s).
A1.3.2 Fuel system components should be cleaned and maintained either periodically or on the basis of operational evidence
(pressure drop across a filter), or on a combination of the two.
A1.4 Significance and Use
D4418 − 22
A1.4.1 The use of fuel-system monitoring and quality control techniques, combined with scheduled cleaning and maintenance,
will minimize the quantity of contaminants reaching the combustor(s) and hence will minimize corrosion and erosion of gas turbine
components.
A1.4.2 The use of fuel monitoring, storage, and handling techniques will limit water, suspended solids, and microbial growth in
the fuel; this in turn will minimize corrosion and erosion of gas turbine components.
A1.5 Sampling
A1.5.1 Samples should be taken at each of the four points as in Fig. A1.1. Consult Practice D4057, for sampling procedures.
A1.5.1.1 A sample should be taken at point 1, on delivery, during transfer into the storage tank.
A1.5.1.2 Fuel storage tank samples should include both tank bottom samples and “all-level” samples. These samples shall be taken
at a frequency to be determined by the user based on the rate of accumulation of water and other contaminants. When the system
consists of multiple tankage, take these samples preparatory to drawing fuel from a given tank. When the gas turbine is used for
infrequent standby or emergency service, take the sample on a closely observed schedule.
A1.5.1.3 Sampling at points three and four is essential to determine the effectiveness of the separation system, if any, and to assure
the quality of the fuel being supplied to the gas turbine. The frequency of such sampling should be determined by the user’s
experience and in consultation with the turbine manufacturer.
A1.6 Inspection and Analysis of Samples
A1.6.1 Inspection and analysis of fuel is very important in determining fuel quality at various locations and times in the fuel
storage and handling system and will ensure that only fuel of acceptable quality will reach the turbine combustor(s). Brief and
visual methods may serve to suggest the presence of some contaminants, but established fuel analysis methods including chemical
analysis for trace elements are needed for more complete judgement of fuel quality.
A1.6.2 The effectiveness of a fuel separation system may best be judged by the use of specialized analytical methods, as
recommended by the equipment suppliers or by fuel vendors. These might include conductivity, dielectric properties, color, content
and quality of particulates, turbidity, spectral properties, or filterability. From such data, useful inferences may be derived to
supplement more detailed chemical analysis.
A1.7 Cleaning and Maintenance
A1.7.1 A relatively long residence of fuel in tankage allows separation of insoluble contaminants, especially water and inorganic
solids. Accumulation of water can generate corrosion product solids and biological slimes. These materials can result in gradual
or sudden overloading of separation equipment and possibly the erosion or plugging of close-tolerance devices such as fuel pumps
and flow dividers.
A1.7.1.1 Water as a separate phase mobilizes oxygen and acidity to effect corrosion or simple rusting of tank metal surfaces, and
gives a medium for biological slime development. The rate of accumulation of water and its products in fuel tank bottoms can be
D4418 − 22
established by appropriate samples at point 2. A schedule of tank stripping should be established to maintain water at a low level.
Careful, slow drawoff rates enable more complete stripping.
A1.7.1.2 Rust or other inorganic debris present in tank bottom from previous corrosion, from peeling of possible protective
coatings, or from tank scale deposits should be removed by appropriate cleaning procedures to prevent downstream damage.
Chronic recurrence of these problems may best be solved by use of special corrosion inhibitors, by incorporation of tank linings,
or by substitution of tankage with better corrosion resistance.
A1.7.2 The role of separation systems in removing contaminants inevitably involves the fouling of such equipment with debris.
In order to sustain effective operation, proper maintenance schedules for cleaning or equipment renewal must be followed.
A1.7.2.1 The proper operation of all types of fuel filters is reduced by fouling and accumulation of contaminants, resulting in
reduced fuel throughout or increased pressure differentials, or both. Operation of screens and barrier filters may be restored by
cleaning, for example, a back-flush sequence. Some cartridge filters cannot be back-flushed and hence must be replaced. Some
coalescing filters, in addition to becoming plugged, may lose their ability to shed coalesced water droplets because of the
accumulation of surfactants on their semipermeable filter media, and also must be replaced.
A1.7.2.2 The proper functioning of both centrifugal and electrostatic separators is compromised to some degree by the
accumulation of solid or semisolid debris, that makes small but important changes in internal geometry. The extent of these effects
and the rate at which they occur depend on the type and level of contamination in fuels. These malfunctions are manifested in a
reduced ability to remove water and particulate matter (see A1.6.2). In both types of equipment, purging sequences for removal
of such debris are possible during operation, but thorough cleaning at longer intervals is also advisable to restore design efficiency.
A1.8 Documentation
A1.8.1 In view of the critical requirements for safe and efficient operation, an adequate record to provide evidence of the amount,
type, and quality of fuel burned in the gas turbine is important to trace the causes of unusual maintenance problems and to assess
the performance of the fuel storage and separation facilities. These records also serve to help the user decide what frequency of
sampling and maintenance operations are required. Such a record should include the date, time, and location of all samples, fuel
source, flow rate, the record of measurements and analyses performed, and pertinent information relevant to the condition and
operation of fuel tankage and contaminant-separation equipment.
A2. PRACTICE FOR THE RECEIPT, STORAGE, AND HANDLING OF TURBINE FUELS CONTAINING RESIDUAL
COMPONENTS
A2.1 Scope
A2.1.1 This practice covers the receipt, storage, handling, and chemical treatment of gas turbine fuels, Grades 3-GT and 4-GT,
...