ASTM A380/A380M-17

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: A380/A380M − 17
Standard Practice for
Cleaning, Descaling, and Passivation of Stainless Steel
Parts, Equipment, and Systems
This standard is issued under the fixed designationA380/A380M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* 1.1.1.2 Passivation is removal of exogenous iron or iron
compounds from the surface of a stainless steel by means of a
1.1 This practice covers recommendations and precautions
chemical dissolution, most typically by a treatment with an
for cleaning, descaling, and passivating of new stainless steel
acid solution that will remove the surface contamination but
parts, assemblies, equipment, and installed systems. These
will not significantly affect the stainless steel itself. This
recommendations are presented as procedures for guidance
process is described in a general way in 6.2.11 and defined
when it is recognized that for a particular service it is desired
precisely in 6.4 with further reference to the requirements of
to remove surface contaminants that may impair the normal
Annex A2 and Part II of the table on acid cleaning of steel.
corrosion resistance, or result in the later contamination of the
Unless otherwise specified, it is this definition of passivation
particularstainlesssteelgrade,orcauseproductcontamination.
that is taken as the meaning of a specified requirement for
The selection of procedures from this practice to be applied to
passivation. (See also Specification A967/A967M.)
the parts may be specified upon agreement between the
1.1.1.3 Passivation is the chemical treatment of a stainless
supplier and the purchaser. For certain exceptional
steel with a mild oxidant, such as a nitric acid solution, for the
applications,additionalrequirementswhicharenotcoveredby
purpose of enhancing the spontaneous formation of the protec-
this practice may be specified upon agreement between the
tive passive metal oxide film. Such chemical treatment is
supplier and the purchaser. Although they apply primarily to
generally not necessary for the formation of the passive metal
materials in the composition ranges of the austenitic, ferritic,
oxide film.
martensitic, and duplex stainless steels, the practices described
1.1.1.4 Passivation does not indicate the separate process of
may also be useful for cleaning other metals if due consider-
descalingasdescribedinSection5,althoughdescalingmaybe
ation is given to corrosion and possible metallurgical effects.
necessary before passivation can be effective. Depending on
1.1.1 The term passivation is commonly applied to several
theapplication,chemicaldescaling(acidpickling)asdescribed
distinctly different operations or processes relating to stainless
in 5.2.1 may provide sufficient passivation as defined in
steels. In order to avoid ambiguity in the setting of
1.1.1.2.
requirements, it may be necessary for the purchaser to define
precisely the intended meaning of passivation. Some of the 1.2 This practice does not cover decontamination or clean-
various meanings associated with the term passivation that are ingofequipmentorsystemsthathavebeeninservice,nordoes
in common usage include the following: it cover descaling and cleaning of materials at the mill. On the
1.1.1.1 Passivation is the process by which a stainless steel other hand, some of the practices may be applicable for these
purposes. While the practice provides recommendations and
will spontaneously form a chemically resistant surface when
exposedtoairorotheroxygen-containingenvironments.Itwas informationconcerningtheuseofacidsandothercleaningand
descaling agents, it cannot encompass detailed cleaning proce-
at one time considered that an oxidizing treatment was neces-
sary to establish this passive metal oxide film, but it is now dures for specific types of equipment or installations. It
thereforeinnowayprecludesthenecessityforcarefulplanning
accepted that this film will form spontaneously in an oxygen-
containing environment providing that the surface has been and judgment in the selection and implementation of such
procedures.
thoroughly cleaned or descaled.
1.3 These practices may be applied when free iron, oxide
scale,rust,grease,oil,carbonaceousorotherresidualchemical
films, soil, particles, metal chips, dirt, or other nonvolatile
This practice is under the jurisdiction of ASTM Committee A01 on Steel,
Stainless Steel and RelatedAlloysand is the direct responsibility of Subcommittee
deposits might adversely affect the metallurgical or sanitary
A01.14 on Methods of Corrosion Testing.
condition or stability of a surface, the mechanical operation of
Current edition approved Sept. 1, 2017. Published September 2017. Originally
a part, component, or system, or contaminate a process fluid.
approved in 1954. Last previous edition approved in 2013 as A380/A380M–13.
DOI: 10.1520/A0380_A0380M-17. The degree of cleanness required on a surface depends on the
*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
A380/A380M − 17
application.Insomecases,nomorethandegreasingorremoval F22Test Method for Hydrophobic Surface Films by the
of gross contamination is necessary. Others, such as food- Water-Break Test
handling, pharmaceutical, aerospace, and certain nuclear
2.2 ISO Standards:
applications, may require extremely high levels of cleanness, ISO14644-1Cleanroomsandassociatedcontrolledenviron-
includingremovalofalldetectableresidualchemicalfilmsand
ments--Part1:Classificationofaircleanlinessbyparticle
contaminantsthatareinvisibletoordinaryinspectionmethods. concentration
ISO14644-2Cleanroomsandassociatedcontrolledenviron-
NOTE 1—The term “iron,” when hereinafter referred to as a surface
ments -- Part 2: Monitoring to provide evidence of
contaminant, shall denote free iron.
cleanroom performance related to air cleanliness by par-
1.4 Attainment of surfaces that are free of iron, metallic
ticle concentration
deposits,andothercontaminationdependsonacombinationof
proper design, fabrication methods, cleaning and descaling,
3. Design
and protection to prevent recontamination of cleaned surfaces.
3.1 Consideration should be given in the design of parts,
Meaningful tests to establish the degree of cleanness of a
equipment, and systems that will require cleaning to minimize
surface are few, and those are often difficult to administer and
the presence of crevices, pockets, blind holes, undrainable
to evaluate objectively. Visual inspection is suitable for the
cavities, and other areas in which dirt, cleaning solutions, or
detection of gross contamination, scale, rust, and particulates,
sludge might lodge or become trapped, and to provide for
but may not reveal the presence of thin films of oil or residual
effective circulation and removal of cleaning solutions. In
chemical films. In addition, visual inspection of internal
equipment and systems that will be cleaned in place or that
surfacesisoftenimpossiblebecauseoftheconfigurationofthe
cannot be immersed in the cleaning solution, it is advisable to
item. Methods are described for the detection of free iron and
slope lines for drainage: to provide vents at high points and
transparent chemical and oily deposits.
drains at low points of the item or system; to arrange for
1.5 This practice provides definitions and describes prac-
removal or isolation of parts that might be damaged by the
tices for cleaning, descaling, and passivation of stainless steel
cleaning solution or fumes from the cleaning solutions; to
parts. Tests with acceptance criteria to demonstrate that the
provide means for attaching temporary fill and circulation
passivation procedures have been successful are listed in 7.2.5
lines; and to provide for inspection of cleaned surfaces.
and 7.3.4, and can also be found in Specification A967/
3.2 In a complex piping system it may be difficult to
A967M.
determine how effective a cleaning operation has been. One
1.6 The values stated in either SI units or inch-pound units
methodofdesigninginspectabilityintothesystemistoprovide
are to be regarded separately as standard. The values stated in
a short flanged length of pipe (that is, a spool piece) at a
each system may not be exact equivalents; therefore, each
location where the cleaning is likely to be least effective; the
system shall be used independently of the other. Combining
spool piece can then be removed for inspection upon comple-
values from the two systems may result in non-conformance
tion of cleaning.
with the standard.
4. Precleaning
1.7 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4.1 Precleaningistheremovalofgrease,oil,paint,soil,grit,
responsibility of the user of this standard to establish appro-
and other gross contamination preparatory to a fabrication
priate safety and health practices and determine the applica-
process or final cleaning. Precleaning is not as critical and is
bility of regulatory limitations prior to use. (For more specific generally not as thorough as subsequent cleaning operations.
safety precautions see 7.2.5.3, 7.3.4, Section 8, A1.7, and
Materials are usually precleaned before hot-forming,
A2.11.) annealing, or other high-temperature operation, before any
1.8 This international standard was developed in accor-
descaling operation, and before any finish-cleaning operation
dance with internationally recognized principles on standard- where the parts will be immersed or where the cleaning
ization established in the Decision on Principles for the
solutions will be reused. Items that are subject to several
Development of International Standards, Guides and Recom- redraws or a series of hot-forming operations, with intermedi-
mendations issued by the World Trade Organization Technical
ateanneals,shallbecleanedaftereachformingoperation,prior
Barriers to Trade (TBT) Committee. to annealing. Precleaning may be accomplished by vapor
degreasing; immersion in, spraying, or swabbing with alkaline
2. Referenced Documents
or emulsion cleaners; steam; or high-pressure water-jet (see
2.1 ASTM Standards:
6.2).
A967/A967MSpecification for Chemical Passivation Treat-
5. Descaling
ments for Stainless Steel Parts
F21Test Method for Hydrophobic Surface Films by the
5.1 General—Descaling is the removal of heavy, tightly
Atomizer Test
adherent oxide films resulting from hot-forming, heat-
treatment, welding, and other high-temperature operations.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available from International Organization for Standardization, ISO Central
the ASTM website. Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva, Switzerland.
A380/A380M − 17
Because mill products are usually supplied in the descaled tions (such as the presence of crevices). If used, neutralization
condition, descaling (except removal of localized scale result- is usually also followed by rinsing with clean water to remove
ingfromwelding)isgenerallynotnecessaryduringfabrication all traces of the neutralizing agent and thorough drying. To
ofequipmentorerectionofsystems(see6.3).Whennecessary, minimize staining, surfaces shall not be permitted to dry
scale may be removed by one of the chemical methods listed between successive steps of the acid descaling and rinsing
below,bymechanicalmethods(forexample,abrasiveblasting, procedure (see A1.5).
sanding, grinding, power brushing), or by a combination of
5.2.6 Chemicaldescalingmethods,factorsintheirselection,
these. and precautions in their use are described in the Metals
Handbook. When chemical descaling is necessary, it should
5.2 Chemical Descaling (Pickling)—Chemical descaling
be done while the part is in its simplest possible geometry,
agents include aqueous solutions of sulfuric acid, or nitric and
before subsequent fabrication or installation steps create inter-
hydrofluoric acids, as described in Annex A1, Table A1.1,
nal crevices or undrainable spaces that may trap descaling
molten alkali or salt baths, and various proprietary formula-
agents, sludge, particles, or contaminated rinse water that
tions.Thesafetyprecautionsof8.6shallbeobservedintheuse
might either result in eventual corrosion or adversely affect
of these methods. Particular care shall be exercised when
operation of the item after it is placed in service.
pickling closed systems and items with crevices or internal
voids to prevent retention of pickling solutions and residues.
5.3 Mechanical Descaling—Mechanical descaling methods
include abrasive blasting, power brushing, sanding, grinding,
5.2.1 Acid Pickling—Nitric-hydrofluoric acid solution is
most widely used by fabricators of stainless steel equipment and chipping. Procedural requirements and precautions for
some of these methods are given in the Metals Handbook.
and removes both metallic contamination, and welding and
heat-treating scales. Its use should be carefully controlled and Mechanicaldescalingmethodshavetheadvantagethattheydo
not produce such physical or chemical conditions as inter-
is not recommended for descaling sensitized austenitic stain-
granular attack, pitting, hydrogen embrittlement, cracks, or
less steels or hardened martensitic stainless steels or where it
smut deposits. For some materials, in particular the austenitic
can come into contact with carbon steel parts, assemblies,
stainless steels when in the sensitized condition and the
equipment,andsystems.SeealsoA1.3.Solutionsofnitricacid
martensitic stainless steels when in the hardened condition,
alone are usually not effective for removing heavy oxide scale.
mechanical descaling may be the only suitable method. Grind-
5.2.2 Surfaces to be descaled shall be precleaned to remove
ing is usually the most effective means of removing localized
oils and greases prior to acid treatment (see A1.5), and are
scale such as that which results from welding. Disadvantages
usually precleaned prior to other chemical treatments.
of mechanical descaling are cost, as compared to chemical
5.2.3 When size and shape of product permit, total immer-
descaling, and the fact that surface defects (for example, laps,
sion in the pickling solution is preferred. Where immersion is
pits, slivers) may be obscured, making them difficult to detect.
impractical, descaling may be accomplished by (1) wetting the
5.3.1 Surfaces to be descaled may have to be precleaned.
surfaces by swabbing or spraying, or (2) by partially filling the
Particular care must be taken to avoid damage by mechanical
item with pickling solution and rotating or rocking to slosh the
methods when descaling thin sections, polished surfaces, and
solution so that all surfaces receive the required chemical
close-tolerance parts. After mechanical descaling, surfaces
treatment. The surface should be kept in contact with agitated
should be cleaned by scrubbing with hot water and fiber
solution for about 15 to 30 min or until inspection shows that
brushes, followed by rinsing with clean, hot water.
complete scale removal has been accomplished. Without
5.3.2 Grinding wheels and sanding materials should not
agitation, additional exposure time may be required. If rocking
contain iron, iron oxide, zinc, or other undesirable materials
or rotation are impracticable, pickling solution may be circu-
that may cause contamination of the metal surface. Grinding
lated through the item or system until inspection shows that
wheels,sandingmaterials,andwirebrushespreviouslyusedon
descaling has been accomplished.
othermetalsshouldnotbeusedonstainlesssteel.Wirebrushes
5.2.4 Over-pickling must be avoided. Uniform removal of
should be of a stainless steel which is equal in corrosion
scale with acid pickling depends on the acid used, acid
resistance to the material being worked on.
concentration, solution temperature, and contact time (see
5.3.3 Clean, previously unused abrasives, such as glass
Annex A1). Continuous exposure to pickling solutions for
beadsoriron-freesilicaoraluminasand,arerecommendedfor
more than 30 min is not recommended. The item should be
abrasive blasting. Steel shot or grit is generally not recom-
drained and rinsed after 30 min and examined to check the
mended because of the possibility of embedding iron particles.
effectiveness of the treatment. Additional treatment may be
The use of stainless steel shot or grit reduces the danger of
required. Most pickling solutions will loosen weld and heat-
rusting and iron contamination, but cannot completely elimi-
treating scale but may not remove them completely. Intermit-
nate the possibility of embedding residues of iron-oxide scale.
tentscrubbingwithastainlesssteelbrushorfiber-bristlebrush,
5.3.4 Ifatotallyironandscalefreesurfaceisrequired,most
in conjunction with pickling or the initial rinse, may facilitate
abrasive blasting may be followed by a brief acid dip (see
the removal of scale particles and products of chemical
Annex A2) or passivation treatment (see 6.4).
reaction (that is, pickling smut).
5.2.5 Afterchemicaldescaling,surfacesshallbethoroughly
rinsed with clean water to remove all traces of residual
chemicals and thoroughly dried after the final water rinse. A
“Surface Cleaning, Finishing, and Coating,” Metals Handbook, Am. Soc.
neutralization treatment may be necessary under some condi- Metals, 9th ed., Vol 5, 1982.
A380/A380M − 17
6. Cleaning 6.2.2 Emulsion Cleaning is a process for removing oily
deposits and other common contaminants from metals by the
6.1 General—Cleaningincludesalloperationsnecessaryfor
use of common organic solvents dispersed in an aqueous
the removal of surface contaminants from metals to ensure (1)
solution with the aid of a soap or other emulsifying agent (an
maximum corrosion resistance of the metal, (2) prevention of
emulsifying agent is one which increases the stability of a
product contamination, and (3) achievement of desired appear-
dispersionofoneliquidinanother).Itiseffectiveforremoving
ance. Cleanness is a perishable condition. Careful planning is
a wide variety of contaminants including pigmented and
necessary to achieve and maintain clean surfaces, especially
unpigmented drawing compounds and lubricants, cutting
where a high degree of cleanness is required. Selection of
fluids, and residues resulting from liquid penetrant inspection.
cleaning processes is influenced mainly by the type of con-
Emulsion cleaning is used when rapid, superficial cleaning is
taminant to be removed, the required degree of cleanness, and
required and when a light residual film of oil is not objection-
cost. If careful control of fabrication processes, sequencing of
able.
cleaning and fabrication operations, and measures to prevent
recontamination of cleaned surfaces are exercised, very little
6.2.3 Solvent Cleaning is a process for removing contami-
special cleaning of the finished item or system may be
nants from metal surfaces by immersion or by spraying or
necessary to attain the desired level of cleanness. If there is a
swabbing with common organic solvents such as the aliphatic
question concerning the effectiveness of cleaning agents or
petroleums, chlorinated hydrocarbons, or blends of these two
procedures, or the possible adverse effects of some cleaning
classesofsolvents.Cleaningisusuallyperformedatorslightly
agents or procedures on the materials to be cleaned, trial runs
above room temperature. Except for parts with extremely
using test specimens and sensitive inspection techniques may
heavycontaminationorwithhard-to-reachareas,orboth,good
be desirable. Descriptions, processes, and precautions to be
agitationwillusuallyeliminatetheneedforprolongedsoaking.
observed in cleaning are given in the Metals Handbook.
Virtually all metal can be cleaned with the commonly used
Proprietary cleaners may contain harmful ingredients, such as
solventsunlessthesolventhasbecomecontaminatedwithacid,
chlorides or sulfur compounds, which could adversely affect
alkali, oil, or other foreign material. Chlorinated solvents are
the performance of a part, equipment, or system under service
not recommended for degreasing of closed systems or items
conditions. It is recommended that the manufacturer of the
with crevices or internal voids.
cleaner be consulted if there is reason for concern.
6.2.4 Vapor Degreasing is a generic term applied to a
NOTE 2—Instances are known where stainless steel vessels have stress
cleaning process that employs hot vapors of a volatile chlori-
cracked before start-up due to steaming out or boiling out with a
nated solvent to remove contaminants, and is particularly
chloride-containing detergent.
effective against oils, waxes, and greases. The cleanness and
6.2 Cleaning Methods—Degreasing and general cleaning
chemical stability of the degreasing solvent are critical factors
may be accomplished by immersion in, swabbing with, or
in the efficiency of the vapor and possible chemical attack of
sprayingwithalkaline,emulsion,solvent,detergent,chelate,or
the metal. Water in the degreasing tank or on the item being
acid cleaners or a combination of these; by vapor degreasing;
cleaned may react with the solvent to form hydrochloric acid,
by ultrasonics using various cleaners; by various mechanical
which is usually harmful to the metal. No water should be
methods; by steam, with or without a cleaner; or by high-
present in the degreasing tank or on the item being cleaned.
pressure water-jetting. The cleaning method available at any
Acids, oxidizing agents, and cyanides must be prevented from
giventimeduringthefabricationorinstallationofacomponent
contaminating the solvent. Materials such as silicones cause
orsystemisafunctionofthegeometriccomplexityoftheitem,
foaming at the liquid-vapor interface and may result in
the type of contamination present, the degree of cleanliness
recontamination of the workpiece as it is removed from the
required, and cost. Methods commonly used for removing
degreaser. Vapor degreasing with chlorinated solvents is not
deposited contaminants (as opposed to scale) are described
recommended for closed systems or items with internal voids
briefly below and in greater detail (including factors to be
or crevices.
considered in their selection and use) in the Metals Handbook
5 6.2.5 Ultrasonic Cleaning is often used in conjunction with
and the SSPC Steel Structures Painting Handbook. The safety
certain solvent and detergent cleaners to loosen and remove
precautions of 8.6 shall be observed in the use of these
contaminants from deep recesses and other difficult to reach
methods. Particular care shall be exercised when cleaning
areas, particularly in small work-pieces. Cavitation in the
closed systems and items with crevices or internal voids to
liquid produced by the high frequency sound causes micro
prevent retention of cleaning solutions and residues.
agitation of the cleaner in even tiny recesses of the workpiece,
6.2.1 Alkaline Cleaning is used for the removal of oily,
making the method especially desirable for cleaning parts or
semisolid, and solid contaminants from metals. To a great
assemblies having an intricate configuration. For extremely
extentthesolutionsuseddependontheirdetergentqualitiesfor
high levels of surface cleanness, high-purity solvents (1 ppm
cleaningactionandeffectiveness.Agitationandtemperatureof
total nonvolatile residue) are required.
the solution are important.
6.2.6 Synthetic Detergents are extensively used as surface-
active agents because they are freer rinsing than soaps, aid in
soils dispersion, and prevent recontamination. They are effec-
Good Painting Practices, Steel Structures Painting Council, Vol 1, 1982,
tive for softening hard water and in lowering the surface and
Chapters 2.0–2.9, 3.1–3.2.
interfacial tensions of the solutions. Synthetic detergents, in
A380/A380M − 17
particular, should be checked for the presence of harmful shall not be permitted to dry between successive steps of the
ingredients as noted in 6.1. acid cleaning and rinsing procedure. Acid cleaning is not
recommended where mechanical cleaning or other chemical
6.2.7 Chelate Cleaning—Chelates are chemicals that form
methods will suffice on the basis of intended use and, as may
soluble, complex molecules with certain metal ions, inactivat-
be necessary, on inspection tests (see 7.2 and 7.3). Require-
ing the ions in solution so they cannot normally react with
mentsforsuperfluouscleaningandinspectiontestingcanresult
another element or ions to produce precipitates or scale. They
in excessive costs. Acid cleaning, if not carefully controlled,
enhancethesolubilityofscalesandcertainothercontaminants,
may damage the surface and may result in further contamina-
do not precipitate different scales when the cleaning solution
tion of the surface.
becomes spent, and can be used on some scales and contami-
6.2.12 Rinsing—After cleaning with an aqueous chemical
nants that even mineral acids will not attack. When properly
cleaning solution, surfaces shall be thoroughly rinsed with
used (chelating agents must be continuously circulated and
clean water to remove all traces of residual chemicals and
must be maintained within carefully controlled temperature
thoroughly dried after the final water rinse. A neutralization
limits), intergranular attack, pitting, and other harmful effects
treatmentmaybenecessaryundersomeconditions(suchasthe
are minimal. Chelating agents are particularly useful for
presence of crevices). If used, neutralization is usually also
cleaning installed equipment and systems.
followedbyrinsingwithcleanwatertoremovealltracesofthe
6.2.8 Mechanical Cleaning (also see 5.3)—Abrasive
neutralizing agent and thorough drying. (See A2.10.)
blasting, vapor blasting using a fine abrasive suspended in
water, grinding, or wire brushing are often desirable for 6.3 CleaningofWeldsandWeld-JointAreas—Thejointarea
and surrounding metal for several inches back from the joint
removing surface contaminants and rust. Cleanliness of abra-
sivesandcleaningequipmentisextremelyimportanttoprevent preparation, on both faces of the weld, should be cleaned
immediately before starting to weld. Cleaning may be accom-
recontamination of the surfaces being cleaned. Although sur-
faces may appear visually clean following such procedures, plished by brushing with a clean stainless steel brush or
scrubbing with a clean, lint-free cloth moistened with solvent,
residual films which could prevent the formation of an opti-
mum passive condition may still be present. Subsequent or both. When the joint has cooled after welding, remove all
accessibleweldspatter,weldingflux,scale,arcstrikes,etc.,by
treatment such as additional iron-free abrasive cleaning
methods, acid cleaning, passivation, or combinations of these grinding. According to the application, some scale or heat
is, therefore, required for stainless steel parts, equipment, and temper may be permissible on the nonprocess side of a weld,
but should be removed from the process side if possible. If
systemstobeusedwherecorrosionresistanceisaprimefactor
to satisfy performance and service requirements, or where chemical cleaning of the process side of the weld is deemed
necessary, the precautions of this standard shall be observed.
product contamination must be avoided.
Austenitic stainless steels in the sensitized condition should
6.2.9 Steam Cleaning is used mostly for cleaning bulky
generally not be descaled with nitric-hydrofluoric acid solu-
objects that are too large for soak tanks or spray-washing
tions. Welds may also be cleaned as described in Table A2.1,
equipment. It may be used with cleaning agents such as
Part III, Treatment P and Q (also see 5.2.4 and 5.2.5).
emulsions, solvents, alkalis, and detergents. Steam lances are
frequently used for cleaning piping assemblies. Steam pres-
6.4 Final Cleaning or Passivation, or Both—If proper care
sures from 345 to 515 kPa [50 to 75 psi] are usually adequate
has been taken in earlier fabrication and cleaning, final
(see 6.1).
cleaning may consist of little more than scrubbing with hot
water or hot water and detergent (such as trisodium phosphate,
6.2.10 Water-Jetting at water pressures of up to 70 MPa
TSP),usingfiberbrushes.Detergentwashingshallbefollowed
[10000 psi] is effective for removing grease, oils, chemical
by a hot-water rinse to remove residual chemicals. Spot
deposits (except adsorbed chemicals), dirt, loose and moder-
cleaning to remove localized contamination may be accom-
ately adherent scale, and other contaminants that are not
plished by wiping with a clean, solvent-moistened cloth. If the
actually bonded to the metal. The method is particularly
purchaser specifies passivation, the final cleaning shall be in
applicable for cleaning piping assemblies which can withstand
accordancewiththerequirementsofTableA2.1,PartII,orone
the high pressures involved; self-propelled nozzles or “moles”
of the treatments listed in Specification A967/A967M. Unless
are generally used for this purpose.
specified by the purchaser, the chemical treatment applied to
6.2.11 Acid Cleaning is a process in which a solution of a
thepartsshallbeselectedbythesupplierfromamongthelisted
mineral or organic acid in water, sometimes in combination
passivation treatments. When the stainless steel parts are to be
with a wetting agent or detergent or both, is employed to
used for applications where corrosion resistance is a prime
remove iron and other metallic contamination, light oxide
factor to achieve satisfactory performance and service
films,shopsoil,andsimilarcontaminants.Suggestedsolutions,
requirements, or where product contamination must be
contact times, and solution temperatures for various alloys are
avoided, passivation followed by thorough rinsing several
given in AnnexA2.Acid cleaning is not generally effective for
timeswithhotwateranddryingthoroughlyafterthefinalwater
removal of oils, greases, and waxes. Surfaces shall be pre-
rinse is recommended, whenever practical.
cleaned to remove oils and greases before acid cleaning. (See
A2.10.) Common techniques for acid cleaning are immersion, 6.5 Precision Cleaning—Certain nuclear, space, and other
swabbing, and spraying. Maximum surface quality is best especially critical applications may require that only very
achieved by using a minimum cleaning time at a given acid high-purity alcohols, acetone, ketones, or other precision
concentration and temperature. To minimize staining, surfaces cleaning agents be used for final cleaning or recleaning of
A380/A380M − 17
critical surfaces after fabrication advances to the point that 6.6.4 When cleaning critical installed systems, do not per-
internal crevices, undrainable spaces, blind holes, or surfaces mit the process surfaces to dry between successive cleaning
andrinsingsteps,orbetweenthefinalrinseandfillingwiththe
that are not accessible for thorough scrubbing, rinsing, and
inspection are formed. Such items are often assembled under layup solution.
clean-room conditions (see 8.5.5) and require approval, by the
purchaser,ofcarefullypreparedcleaningproceduresbeforethe 7. Inspection After Cleaning
start of fabrication.
7.1 General—Inspection techniques should represent
6.6 Cleaning of Installed Systems—There are two ap- careful, considered review of end use requirements of parts,
equipment, and systems. There is no substitute for good,
proaches to cleaning installed systems. In the first, which is
probablyadequateformostapplications,cleaningsolutionsare uniform, cleaning practices which yield a metallurgically
sound and smooth surface, followed by adequate protection to
circulated through the completed system after erection, taking
preservethatcondition.Establishmentofthemostreliabletests
care to remove or protect items that could be damaged during
the cleaning operation. In the second approach, which may be and test standards for cleanness are helpful in attaining the
desired performance of parts, equipment, and systems. Testing
required for gaseous or liquid oxygen, liquid metal, or other
should be sufficiently extensive to ensure the cleanness of all
reactive-processsolutions,pipingandcomponentsareinstalled
surfaces exposed to process fluids when in service. The
in a manner to avoid or minimize contamination of process-
following represent some tests that have been successfully
solution surfaces during erection so that little additional
applied to stainless steels. The purchaser shall have the option
cleaning is necessary after erection; post-erection flushing, if
of specifying in his purchase documents that any of these
necessary,isdonewiththeprocessfluid.Ifprocesssurfacesare
quality assurance tests be used as the basis for acceptability of
coated with an appreciable amount of iron oxide, a chelating
the cleanness of the stainless steel item, the absence of iron on
treatment or high-pressure water-jetting treatment should be
the surface, or both.
considered in place of acid treatment (see 6.2.7 and 6.2.10).
6.6.1 Post-Erection Cleaning—Circulate hot water to which
7.2 Gross Inspection:
a detergent has been added, for at least 4 to 8 h. A water
7.2.1 Visual—Itemscleanedinaccordancewiththispractice
temperature of at least 60 to 70°C [140 to 160°F] is recom-
should be free of paint, oil, grease, welding flux, slag,
mended(see6.1).Rinsebycirculatingcleanhotwateruntilthe
heat-treating and hot-forming scale (tightly adherent scale
effluent is clear. If excessive particulate matter is present, the
resulting from welding may be permissible on some surfaces),
cleaning cycle may be preceded with a high-pressure steam
dirt, trash, metal and abrasive particles and chips, and other
blow, repeating as necessary until a polished-aluminum target
gross contamination. Some deposited atmospheric dust will
ontheoutletofthesystemisnolongerdulledandscratchedby
normally be present on exterior surfaces but should not be
particulates loosened by the high-velocity steam. Valves and
presentoninteriorsurfaces.Visualinspectionshouldbecarried
similar items must be protected from damage during a steam
out under a lighting level, including both general and supple-
blow.
mentary lighting, of at least 1080 lx [100 footcandles], and
6.6.2 If metallic iron is detected by one of the methods
preferably 2700 lx [250 footcandles] on the surfaces being
suggestedinSection7,itcanberemovedbycirculatingoneof
inspected. Visual inspection should be supplemented with
the acid passivation solutions suggested in 6.4 until laboratory borescopes, mirrors, and other aids, as necessary, to properly
determination for iron, made on samples of the solution taken examine inaccessible or difficult-to-see surfaces. Lights should
hourly,indicatesnofurtherincreaseinironcontent,afterwhich be positioned to prevent glare on the surfaces being inspected.
circulation may be stopped and the system drained. After this
7.2.1.1 Gross Indications of Iron—When iron contamina-
treatment, circulate clean hot water (that is, without detergent)
tion is clearly visible, items should be cleaned in accordance
through the system for4hto remove all traces of acid and
with this practice.
corrosionproductresultingfromtheacidtreatment,oruntilthe
7.2.2 Wipe Tests—Rubbing of a surface with a clean, lint-
pH of the rinse water returns to neutral.
free, white cotton cloth, commercial paper product, or filter
6.6.3 In critical systems where post-erection cleaning is not
paper moistened (but not saturated) with high-purity solvent
desirable (for example, liquid oxygen or nuclear reactor
(see 6.5), may be used for evaluating the cleanness of surfaces
primary coolant systems), on-site erection may be conducted
not accessible for direct visual inspection. Wipe tests of small
underclean-roomconditions.Erectioninstructionsmayrequire
diameter tubing are made by blowing a clean white felt plug,
that wrapping and seals of incoming materials and equipment
slightly larger in diameter than the inside diameter of the tube,
be kept intact until the item is inside the clean area, and that
through the tube with clean, dry, filtered compressed air.
careful surveillance be exercised to prevent foreign materials
Cleanness in wipe tests is evaluated by the type of contamina-
(for example, cleaning swabs or tools) from being dropped or tion rubbed off on the swab or plug.The presence of a smudge
left in the system. Where contamination does occur, the
on the cloth is evidence of contamination. In cases of dispute
cleaning procedure usually is developed through consultation concerning the harmful nature of the contamination, a sample
between the erector and the purchaser (or his site representa-
of the smudge may be transferred to a clean quartz microscope
tive). Frequently, post-erection flushing is accomplished by slide for infrared analysis. The wipe test is sometimes supple-
circulating the process fluid through the system until contami-
mented by repeating the test with a black cloth to disclose
nation is reduced to tolerable levels. contaminants that would be invisible on a white cloth.
A380/A380M − 17
7.2.3 Residual Pattern—Dry the cleaned surface after copper sulfate in the following proportions (Warning—
finish-cleaning at 50°C [120°F] for 20 min. The presence of Always add acid to cold water.):
stains or water spots on the dried surfaces indicates the
Distilled water 90 mL
95–100 % Sulfuric acid (H SO)5.4mL
2 4
presence of residual soil and incomplete cleaning. The test is
Copper sulfate pentahydrate (CuSO ·5H O) 4 g
4 2
rapid but not very sensitive.
7.3 Precision Inspection:
7.2.4 Water-Break Test—This is a test for the presence of
7.3.1 Solvent-Ring Test is a test to reveal the presence of
hydrophobiccontaminantsonacleanedsurface.Itisapplicable
tightly adherent transparent films that may not be revealed by
only for items that can be dipped in water and should be made
visual inspection or wipe tests. A comparison standard is
withhigh-puritywater.Thetestprocedureandinterpretationof
preparedbyplacingonacleanquartzmicroscopeslideasingle
results are described in Test Method F22. The test is moder-
drop of high-purity solvent and allowing it to evaporate. Next
ately sensitive.
place another drop on the surface to be evaluated, stir briefly,
7.2.5 Tests for Free Iron:
and transfer, using a clean capillary or glass rod, to a clean
7.2.5.1 Water-Wetting and Drying—Formation of rust stains
quartzmicroscopeslideandallowthedroptoevaporate.Make
may be accelerated by periodically wetting the surface with
as many test slides as necessary to give a reasonable sample of
preferably distilled or deionized water or clean, fresh, potable
the surface being examined. If foreign material has been
tap water.Application via a hand held sprayer or atomizer that
dissolved by the solvent, a distinct ring will be formed on the
produces small droplets that do not coalesce is optimal. The
outer edge of the drop as it evaporates. The nature of the
sample should be rewet as needed but allowed to air dry
contaminant can be determined by infrared analysis, compar-
completely at least 8 times, remaining dry for at least 45
ing the infrared analysis with that of the standard.
minutes each, and totaling 7 to9hina 24-h test period.After
7.3.2 Black Light Inspection is a test suitable for the
completionofthistest,thesurfaceshouldshownoevidenceof
detectionofcertainoilfilmsandothertransparentfilmsthatare
rust stains or other corrosion products.
not detectable under white light. In an area that is blacked out
7.2.5.2 High-Humidity Test—Subject the surface to 95 to
to white light, inspect all visible accessible surfaces with the
100% humidity at 40 to 45°C [100 to 115°F] in a suitable
aid of a new, flood-type, ultraviolet lamp. For inaccessible
humidity cabinet for 24 to 26 h. After completion of this test,
areas,useawipetestasdescribedin7.2.2andsubjecttheused
the surface should show no evidence of rust stains or other
cloth or plug to ultraviolet lamp inspection in a blacked-out
corrosion products.
area. Fluorescence of the surface, cloth, or plug indicates the
7.2.5.3 Copper Sulfate Test—This highly sensitive method
presence of contaminants.The nature of the contamination can
isrecommendedforthedetectionofmetallicironorironoxide
be determined by subjecting a sample of the contaminant, that
on the surface of austenitic 200 and 300 Series, duplex, the
has been transferred to a clean quartz microscope slide, to
precipitation hardening alloys, and the ferritic 400 Series
infrared analysis. The test will not detect straight-chain hydro-
stainless steels containing 16% chromium or more. It is not
carbons such as mineral oils.
recommended for the martensitic and lower chromium ferritic
7.3.3 AtomizerTestisatestforthepresenceofhydrophobic
stainless steels of the 400 Series since the test may show a
films. It is applicable to both small and large surfaces that are
positivereactiononthesematerialsirrespectiveofthepresence
accessible for direct visual examination, and is about 100×
or absence of anodic surface contaminants.The test solution is
more sensitive than the water-break test. The test procedure
preparedbyfirstaddingsulfuricacidtodistilledwaterandthen
and interpretation of results are described in Test Method F21.
dissolving copper sulfate in the following proportions
High-purity water should be used for the test.
(Warning—Always add acid to cold water.):
7.3.4 FerroxylTestforFreeIronisahypersensitivetestand
Distilled water 250 mL shouldbeusedonlywheneventracesoffreeironorironoxide
95–100 % Sulfuric acid (H SO)1mL
2 4
might be objectionable. The test can be used on stainless steel
Copper sulfate pentahydrate (CuSO ·5H O) 4 g
4 2
to detect iron contamination from sources including, but not
Apply the test solution to the surface to be inspected,
limited to, iron-tool marks, residual-iron salts from pickling
applying additional solution if needed to keep the surface wet
solutions, iron dust, atmospheric exposure, iron deposits in
for a period of 6 min. The specimen shall be rinsed and dried
welds, embedded iron and iron oxide. The test solution is
in a manner not to remove any deposited copper. A copper
prepared by first adding nitric acid to distilled water and then
deposit indicates the presence of free iron.
adding potassium ferricyanide, in the following proportions:
7.2.5.4 Martensitic Grade Adherent Copper Sulfate Test—
Distilled water 94 weight % 1000 mL [1 gal]
The copper sulfate test as set forth in 7.2.5.3 is not applicable Nitric acid (60–67 %) 3 weight % 20 mL [0.2 pt]
Potassium ferricyanide 3 weight % 30 g [4 oz]
to surgical and dental instruments made of hardened marten-
The test solution shall be mixed fresh the day the tests are
siticstainlesssteels.Instead,aspecializedcoppersulfatetestis
extensively used for the purpose of detecting free iron and made since it changes color on standing. Apply solution with
an aluminum, plastic, glass, or rubber atomizer having no iron
determining overall good manufacturing practice. Copper de-
posits on the surface of such instruments are wiped with or steel parts, or a swab (atomizer spray is preferred).
moderate vigor to determine if the copper is adherent or 7.3.4.1 The appearance of a blue stain within 15 s of
nonadherent. Instruments with nonadherent copper are consid- application is evidence of surface iron contamination. Several
ered acceptable. The specialized test solution is prepared by minutes may be required for detection of oxide scale. The
first adding sulfuric acid to distilled water and then dissolving solution should be removed from the surface as quickly as
A380/A380M − 17
possibleaftertestingusingwateror,ifnecessary,whitevinegar sludge in the bottom of cleaning tanks; the formation of oil,
or a solution of 5 to 20 weight% acetic acid and scrubbing scums, and undissolved matter on liquid surfaces; and high
with a fiber brush. Flush the surface with water several times conc
...