ASTM D4418-88(1998)
(Practice)Standard Practice for Receipt, Storage, and Handling of Fuels for Gas Turbines
Standard Practice for Receipt, Storage, and Handling of Fuels for Gas Turbines
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 and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn. Contact ASTM International (www.astm.org) for the latest information.
Designation: D 4418 – 88 (Reapproved 1998) An American National Standard
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Practice for
Receipt, Storage, and Handling of Fuels for
Gas Turbines
This standard is issued under the fixed designation D 4418; 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.
1. Scope designate the fuel that is actually burned in the gas turbine.
Fuel may actually be sampled at a point upstream from the
1.1 This practice covers the receipt, storage, and handling of
point of entry into the combustor(s), provided the sample is
fuels for gas turbines, except for gas turbines used in aircraft.
representative of the fuel actually entering the combustor(s).
It is intended to provide guidance for the control of substances
3.2 fuel contaminants—in principle, are any fuel component
in a fuel that could cause deterioration of either the fuel system,
other than hydrocarbon oils. In the present context the con-
or the gas turbine, or both.
taminants are foreign materials that make the fuel less suitable
1.2 This practice provides no guidance for either the selec-
or even unsuitable for the intended use. The contaminants of
tion of a grade of fuel, a topic covered by Specification D 2880,
primary interest are foreign materials introduced subsequent to
or for the safety aspects of the fuel and fuel systems. For
the manufacture of specification quality fuel. Hence they are
example, this practice does not address the spacings of storage
materials introduced in the distribution system (that is storage
tanks, loading and unloading facilities, etc., and procedures for
tanks, pipelines, tank, trucks, barges, etc.), or in the user’s
dealing with the flammability and toxic properties of the fuels.
storage and handling systems, or generated within these
1.3 The values stated in SI units are to be regarded as the
systems (rust generated in steel pipes and tanks by moist fuel,
standard. The values given in parentheses are for information
etc.). Contaminants may be soluble or insoluble in the fuel.
only.
3.3 dissolved and free water—water may be present in the
1.4 This standard does not purport to address all of the
fuel as dissolved water or as “free” (undissolved) water, or
safety concerns, if any, associated with its use. It is the
both. The free water may be fresh or saline. Fresh water may
responsibility of the user of this standard to establish appro-
enter the fuel from steam coils in storage tanks, from conden-
priate safety and health practices and determine the applica-
sation out of moisture-laden air, or from leaking cooling coils.
bility of regulatory limitations prior to use.
Saline water can enter the fuel during transportation in barges
2. Referenced Documents or tankers.
3.4 particulate solids—may enter a fuel from the air (sus-
2.1 ASTM Standards:
pended dirt and aerosols) or from the distribution and storage
D 1500 Test Method for ASTM Color of Petroleum Prod-
systems (rust, corrosion products, gasket debris, and so forth).
ucts (ASTM Color Scale)
3.5 metallic compounds—metals may be present as metallic
D 1796 Test Method for Water and Sediment in Fuel Oils by
compounds in the fuel as a natural result of the composition of
the Centrifuge Method (Laboratory Procedure)
the crude oil and of the refining process. However, unless
D 2274 Test Method for Oxidation Stability of Distillate
special precautions are taken, additional metallic compounds
Fuel Oil (Accelerated Method)
can be acquired during distribution and storage. A commercial
D 2276 Test Methods for Particulate Contaminant in Avia-
product pipeline may contain residues of lead-containing
tion Turbine Fuels
gasoline that would then be dissolved by the gas turbine fuel.
D 2880 Specification for Gas Turbine Fuel Oils
Tank trucks, railroad tankcars, barges, and tankers may be
D 4057 Practice for Manual Sampling of Petroleum and
inadequately cleaned and contain residues of past cargos.
Petroleum Products
Acidic components in saline water salts in the fuel may react
3. Terminology
with distribution and storage equipment.
3.6 microbial slimes—may result when conditions are con-
3.1 fuel entering the combustor(s)—this term is used to
ducive to the growth of microorganisms that are always
present. The presence of free water is essential to the growth of
This practice is under the jurisdiction of ASTM Committee D-2 on Petroleum
many of these microorganisms that grow in tank water bottoms
Products and Lubricantsand is the direct responsibility of Subcommittee D02.Eon
and feed on nutrients in the water or on the hydrocarbons.
Burner, Diesel, and Gas Turbine Fuel Oils.
Current edition approved Oct. 31, 1988. Published February 1989. Originally
published as D 4418 – 84. Last previous edition D 4418 – 84.
4. Summary of Practice
Annual Book of ASTM Standards, Vol 05.01.
3 4.1 The body of this practice defines the contaminants
Annual Book of ASTM Standards, Vol 05.02.
D 4418
frequently found in turbine fuel oils and discusses the sources particulates like rust. They are dissolved or suspended either in
and significance of such contaminants. the fuel hydrocarbons or in free water present in the fuel. The
4.2 Annex A1 is a guide for the receipt, storage, and significance of several individual trace metals with respect to
handling of distillate gas turbine fuels, Grades 1-GT and 2-GT, hot corrosion is discussed in 6.1.4 through 6.1.5. Although
in accordance with Specification D 2880. lower levels of trace metals in a fuel will promote longer
4.3 Annex A2 is a guide for the receipt, storage, and turbine service from a corrosion standpoint, the specification of
handling of gas turbine fuels, Grades 3-GT and 4-GT, that excessively low levels may limit the availability of the fuel or
contain residual components. materially increase its cost. Table 1 suggests levels of trace
4.4 Annex A3 is a guide for the selection and storage of metals that would probably yield satisfactory service.
fuels intended for long-term storage, when such fuels are 6.1.4 Ash is the noncombustible material in an oil. Ash-
distillate fuels. forming materials may be present in fuel oil in two forms: (1)
4.5 Annex A4 is a guide for gas turbine users who are solid particles, and (2) oil- or water-soluble metallic com-
considering the use of fuels from alternative non-petroleum pounds. The solid particles are for the most part the same
sources. material that is designated as sediment in the water and
sediment test. Depending on their size, these particles can
5. Significance and Use
contribute to wear in the fuel system and to plugging of the fuel
5.1 This practice provides the user of gas turbine fuel oils
filter and the fuel nozzle. The soluble metallic compounds have
and the designer of gas turbine fuel systems with an apprecia-
little or no effect on wear or plugging, but they can contain
tion of the effects of fuel contaminants and general methods of
elements that produce turbine corrosion and deposits as de-
controlling such contaminants in gas turbine fuel systems. scribed in 6.1.5.
5.2 This practice is general in nature and should not be
6.1.5 Vanadium and Lead—Fuel contaminants might in-
considered a substitute for any requirement imposed by war- clude soluble compounds such as vanadium porphyrins, me-
ranty of the gas turbine manufacturer, or by federal, state, or
tallic soaps, or tetraethyl lead that cannot be removed from the
local government regulations. fuel at the gas-turbine site.
5.3 Although it cannot replace a knowledge of local condi-
6.1.5.1 Vanadium can form low melting compounds such as
tions or the use of good engineering and scientific judgment, vanadium pentoxide which melts at 691°C (1275°F), and
this practice does provide guidance in development of indi-
causes severe corrosive attack on all of the high-temperature
vidual fuel management systems for the gas turbine user.
alloys used for gas-turbine blades. If there is sufficient magne-
sium in the fuel, it will combine with the vanadium to form
6. Significance of Contaminants
compounds with higher melting points and thus reduce the
6.1 Contamination levels in the fuel entering the combus-
corrosion rate to an acceptable level. The resulting ash will
tor(s) must be low for improved turbine life. Low contamina-
form deposits in the turbine and will require appropriate
tion levels in the fuel in the turbine’s in-plant fuel system are
cleaning procedures.
required to minimize corrosion and operating problems. Pro-
6.1.5.2 When vanadium is present in more than trace
viding fuel of adequate cleanliness to the gas turbine combus-
amounts either in excess of 0.5 ppm or a level recommended
tor(s) may require special actions by the user. These actions
by the turbine manufacturer, it is necessary to maintain a
might include special transportation arrangements with the fuel
weight ratio of magnesium to vanadium in the fuel of not less
supplier, particular care in on-site fuel storage and quality
than 3.0 in order to control corrosion.
control procedures, and establishment of on-site cleanup pro-
6.1.5.3 An upper limit of 3.5 is suggested since larger ratios
cedures. Each of the four classes of contaminants defined in 3.2
will lead to unnecessarily high rates of ash deposition. In most
has its own significance to system operation.
cases, the required magnesium-to-vanadium ratio will be
6.1.1 Water will cause corrosion of tanks, piping, flow
obtained by additions of magnesium-containing compounds to
dividers, and pumps. Corrosion or corrosion products in
the fuel oil. The special requirements covering the addition and
close-tolerance devices, such as flow dividers, may cause
type of magnesium-containing additive, or equivalent, shall be
plugging and may stop flow to the turbines. Free water is
specified by mutual agreement between the various interested
potentially corrosive in sulfur-containing fuels, it may be
parties. The additive will vary depending on the application,
particularly corrosive. Free water may contain dissolved salts
but it is always essential that there is a fine and uniform
that may be corrosive, and may encourage microbiological
dispersion of the additive in the fuel at the point of combustion.
growth.
6.1.2 Particulate Solids may shorten the life of fuel system
TABLE 1 Trace Metal Limits of Fuel Entering Turbine
components. Life of fuel pumps and of various close-tolerance
Combustor(s)
devices is a function of particulate levels and size distributions
Trace Metal Limits by Weight, max, ppm
in the fuel. High levels of particulates can lead to short cycle
Designation
Sodium plus
times in the operation of filters, filter/separators, centrifuges,
Vanadium Calcium Lead
Potassium
and electrostatic purifiers. Since such separation devices do not
No. 0-GT 0.5 0.5 0.5 0.5
remove all the particulates, certain quantities will be present in
No. 1-GT 0.5 0.5 0.5 0.5
the down-stream fuel.
No. 2-GT 0.5 0.5 0.5 0.5
No. 3-GT 0.5 0.5 0.5 0.5
6.1.3 Trace Metals refer both to those metals present as
No. 4-GT (Consult turbine manufacturers)
metallic compounds in solution and to metals present in
D 4418
6.1.5.4 For gas turbines operating at turbine-inlet gas tem- turbines operating at turbine inlet gas temperatures below
peratures below 650°C (1200°F), the corrosion of the high- 650°C (1200°F), the corrosion due to sodium compounds is of
temperature alloys is of minor importance, and the use of a minor importance and can be further reduced by silicon-base
silicon-base additive will further reduce the corrosion rate by additives. A high sodium content is even beneficial in these
absorption and dilution of the vanadium compounds. turbines because it increases the water-solubility of the depos-
6.1.5.5 Lead can cause corrosion, and in addition it can its and thereby increases the ease with which gas turbines can
spoil the beneficial inhibiting effect of magnesium additives on be water-washed to obtain recovery of the operating perfor-
vanadium corrosion. Since lead is only rarely found in signifi- mance.
cant quantities in crude oils, its appearance in the fuel oil is 6.1.6.3 Calcium is not harmful from a corrosion standpoint:
primarily the result of contamination during processing or in fact, it serves to inhibit the corrosive action of vanadium.
transportation. However, calcium can lead to hard-bonded deposits that are not
6.1.6 Sodium, Potassium, and Calcium—Fuel contaminants self-spalling when the gas turbine is shut down, and are not
might also include fuel-insoluble materials such as water, salt, readily removed by water washing of the turbine. The fuel-
or dirt, potential sources of sodium, potassium, and calcium. washing systems, used at some gas turbine installations to
These are normally removed at the gas-turbine site, unless such reduce the sodium and potassium level, will also significantly
contaminants are extremely finely divided. lower the calcium content of fuel oil.
6.1.6.1 Sodium and Potassium can combine with vanadium 6.1.7 Microbial Slimes caused by microorganisms can plug
to form eutectics that melt at temperatures as low as 566°C filters and other close-tolerance openings. Some organisms can
(1050°F) and can combine with sulfur in the fuel to yield cause corrosion as well as produce slimes. Under anaerobic
sulfates with melting points in the operating range of the gas conditions, hydrogen sulfide, which may cause corrosion, can
turbine. These compounds produce severe corrosion, and for be generated by biological action. Biocides are available for
turbines operating at gas inlet temperatures above 650°C controlling the growth of microorganisms, but their effect on
(1200°F), additives are not yet in general use that control such trace metal levels and other fuel properties should be consid-
corrosion. ered. Since water is required for the growth of the microor-
6.1.6.2 Accordingly, the sodium-plus-potassium level must ganisms, one way of controlling their growth is to eliminate the
be limited, but each element is measured separately. Some gas presence of water through tank-stripping operations or other
turbine installations incorporate systems for washing oil with separation techniques.
water to reduce the sodium-plus-potassium level. In installa-
7. Keywords
tions where the fuel is moved by sea transport, the sodium-
plus-potassium level should be checked prior to use to ensure 7.1
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.