API-936 STUDY MATERIAL
 |
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Scope:-
The
responsibilities of inspection personnel who monitor and direct
the quality
control process of monolithic Refractories.
Monolithic
refractories:-
Castable or
plastic refractories applied by casting, gunning, or hand/
ram packing
to form monolithic lining structures of any shape.
Key
elements of Quality control:-
a)
Documentation:-
Owner specification and/or contractor execution
plan.
b)
Material qualification:- Testing at independent or manufacturer's
laboratory.
Inspector directs sampling, monitors specimen
preparation
and witnesses testing.
c)
Applicator qualification:- Contractor demonstration of capabilities
in simulated
installation which is witnessed and inspected by the
inspector.
d)
Installation monitoring:- Inspector monitors contractor work and
test sample
preparation.
Key elements
of Quality control:-
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e)
As-installed testing:-
Inspector coordinates sampling and testing
of
as-installed materials.
f)
Pre-dry out inspection:- Inspector performs visual/hammer test
inspection
of applied linings.
g) Dry
out monitoring:- For
dry out prior to normal start-up of
equipment,
the inspector monitors heating rates and hold times.
h) Post
dry out inspection:-
Inspector performs visual/hammer test
inspection
of applied linings.
Responsibilities
Owner
The owner
shall prepare a detailed specification. Which incude
following
Design
details.
a)Lining
products, thickness, method of application, and extent of
coverage.
b)Anchor
materials, geometry, layout and weld details,Suggested
color coding
for metallic anchors
c) Details
of metal fiber reinforcement including dimensions,
concentration,
type, and metallurgy.
d) Curing
and dryout procedures, including constraints on dryout
heating
(e.g. design
temperature limits and/or maximum differential
temperatures
that shall be maintained to avoid damaging the unit
and/or
components).
Quality
requirements
Physical
property requirements to be used for qualification and
installation
quality control by specific product, installation method
and location
where the product will be utilized.
Sampling
frequency as product intended to use either abrasion
service or
other service .
Required
lining thickness tolerances.
Criteria for
hammer testing and the extent of cracking and surface
voids
permitted.
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Approve
The owner
shall approve the engineering drawings, execution plan
and dryout
procedure prior to any installation activity.
Resolve
exceptions,
substitutions, and deviations to the requirements of the
execution
plan, this standard, and other referenced documents;
conflicts
between the execution plan, this standard, and other
referenced
documents.
actual or
potential work deficiencies discovered and submitted by
the
inspector.
The
contractor shall prepare a detailed execution plan in
accordance
with this standard and the requirements of the owner's
specification
and quality standards.
The
execution plan shall approval, and agreed to in full before work
starts.
Execution
details shall include:
designation
of responsible parties
designation
of inspection hold points and the required advance
notification
to be given to the inspector
surface
preparation and welding procedures.
procedures
for material qualification, material storage, applicator
qualification,
installation and quality control.
curing
(including the curing compound, if any , to be used) and
dryout
procedures for the completed lining system.
Contractor
`
2.
Submission to the owner of all exceptions, substitutions, and
deviations
to the requirements of the execution plan, this standard
and other
referenced documents. Owner's approval shall be secured
before
implementation of the changes.
3.
Scheduling of material qualification tests and delivery of those
materials
and test results to the site.
4.
Scheduling and execution of work to qualify all equipment and
personnel
required to complete installation work including
documentation
and verification by the inspector.
Contractor
`
5.
Preparation and identification of all testing samples (preshipment,
applicator
qualification, and production/ installation) and timely
delivery to
the testing laboratory.
6. Advance
notification to the owner of the time and location where
work will
take place so that this information Can be passed on to
the
inspector.
7. Execution
of installation work, including preparation of as-installed
samples .
8. Provide
inspector verified documentation of installation records,
including:
product(s)
being applied.
pallet code
numbers and location where applied.
installation
crew members (designating nozzleman and gun
operator
when gunning.
mixing
and/or gunning equipment utilized.
fiber and
water percentages.
mixing
details including time, temperature, and aging time (if
gunned).
location and
identity of samples taken for installation quality
control.
shell
temperatures.
weather
conditions and any other unusual conditions or
occurrences.
dryout
records.
9.
Accountability for installed refractories meeting specified standards,
including
as-installed testing results and lining thickness tolerance
limits .
Inspector
Ensure that
material and applicator qualification test results are
fully
documented.
Monitor
qualification, production work and dryout (when applicable)
conducted by
the manufacturer and contractor to ensure
compliance
with job specifications and agreed-to quality practices.
Notify the
owner and the contractor of any work deficiencies or
potential
deficiencies. Notification shall be made according to the
job specific
requirements outlined in the procedures. Notification
shall take
place as soon as possible, and shall occur within one
working day
after discovery of the deficiency.
The
inspector shall make no engineering decisions unless
approved by
the owner.
Conflicts
between the specified execution plan and the actual
installation
procedures or installed refractory quality results shall
be submitted
to the owner for resolution.
Inspect and
hammer test installed linings before dryout and after
dryout (when
possible), and report any anomalies to the owner.
Check and
verify that accurate installation and dryout records are
being
documented by the contractor .
Record all
non-conformances and/or potential problems to which
the inspector
has alerted the contractor and owner.
Manufacturer
`
provide a
compliance datasheet for each product.
provide
material that meets the approved compliance datasheet.
provide all
documentation required .
for plastic
refractories, provide the minimum acceptable
workability
index (per ASTM C181) for successful refractory
application.
Inspector
Qualifications
The
inspector shall have no commercial affiliations with the
contractor
or manufacturer(s).
The inspector
shall be certified .
The
inspector shall possess this standard, owner specifications,
the project
execution plan, and other specific requirements
outlined by
the owner, contractor , and/or manufacturer.
The
inspector shall have working knowledge of these documents.
The
inspector shall submit a resume documenting their experience
(including
similar materials and application) to the owner for
approval.
Materials
1)
Physical Property Requirements
a)
Refractories applied in accordance with this standard shall be
sampled and
tested to verify that the physical properties meet
intended
criteria, product specific physical property requirements
shall be
determined by agreement prior to material qualification.
Qualification
shall be based upon the sampling/testing procedures
described in
this standard.
b) The
acceptance/rejection criteria for both material and applicator
qualification
testing are determined by average physical properties
for each
sample, which shall fully meet the criteria established for
that
material .
c)
Acceptance/rejection criteria for as-installed testing shall be
based upon
criteria and procedures agreed to prior to work start.
The physical
properties criteria shall be extended to account for
field
conditions.
2 )
Storage
a)
General
Refractory
materials are affected by moisture, humidity and
elevated
ambient temperatures. Proper storage of these materials
is critical
to the development of optimal physical properties. Shelf
life is also
affected by the ambient conditions. Storing refractory in
the proper
conditions will enhance shelf life.
b)
Weather Protection
Refractory
materials shall be stored in a weather protected area.
The storage
facility shall prevent moisture contact with the
refractory.
Storage shall be on an elevated, ventilated platform.
Moisture
shall be directed away from the refractory.
c)
Temperature
Refractory
materials shall be stored at a temperature of 40°F to
100°F (5°C
to 38°C).
d) Shelf
Life
Time limits
for material tests shall set the refractory shelf life
requirements.
if the manufacturer`s recommendations are more
stringen ;
the manufacturer`s recommendations shall apply.
e)
Discarding Criteria
Materials
that exceed the shelf life shall be discarded. Packages
with broken
seals or that have become damp or wet or for plastics
only
,refractory with workability index below the manufacturer`s
minimum
required value shall be subject to re-qualification or
discard
3)
Packaging and Marking
a)
General
Packaging of
refractory is important to preserving the integrity of
the
material. Markings provide valuable information to determine
the age of
material, assist in establishing water content
requirements
and track the placement of material as defined in the
quality
control program provided by the contractor.
b)
Regulations and Material Safety Datasheets (MSDS)
Refractory
materials shall comply with all applicable federal,
state, and
local codes and regulations on storage, handling,
safety, and
environmental requirements.
The latest
issue of the refractory manufacturer's compliance
datasheets,
application instructions, and MSDS shall be
available at
the installation site and complied with during the
installation
of monolithic refractory linings.
c) Packaging
Hydraulic
bonded castable
refractories
shall be packaged in sealed, moisture-proof bags.
Chemical
setting
refractories
shall be packaged in heat-sealed plastic to assure
vapor-tight
enclosure. Mechanical protection shall be provided by
cardboard,
rigid plastic or metal outside containers.
d)
Marking
Refractory
bags or containers shall be marked with the product
name, batch
number and date of manufacture clearly shown.
Refractory
bags or containers shall be marked with the contained
refractory
weight. The actual weight shall not deviate from the
marked
weight by more than ± 2%.
The bag or
container for cast, hand-packed or rammed mixes shall
be marked
with the mixing instructions.
Each pallet
shall be uniquely identified by pallet code number and
code date.
4)
Anchors
Selection,
installation, inspection and testing of anchors shall be in
accordance
with the design drawings and specifications.
Qualification
and Testing
a)
General
Testing
shall be in strict accordance with ASTM procedures as
modified
below. The laboratory conducting the test procedures shall
be subject
to audit and approval by the owner.
Quality
control testing shall consist of density, cold crushing
strength
(CCS), permanent linear change (PLC), abrasion loss (when
applicable),
and workability index (plastics only). Other tests
required by
the owner shall be as defined in the owner`s
specifications.
b) Cold
Crushing Strength (CCS)
Testing
shall be in accordance with ASTM C133, and the following.
Cube loading
surfaces shall be parallel to within a tolerance of ± 1 /
32 in. (±
0.8 mm) and perpendicular to within a tolerance of ± 1
degree,
whether cast or gunned.
CCS shall be
determined on samples that have been fired to 1500°F
(815°C) .
NOTE Green
density shall be determined before drying or firing.
The loading
head of the test machine shall have a spherical bearing
block.
For cast or
hand packed specimens, the load shall be applied to
either pair
of faces cast against the side of the mold.
For
specimens cut from a larger cast panel, an open face shall not
be used for
the top or bottom (i.e. load application faces) during the
test.
For gunned
specimens, load shall be applied perpendicular to the
gunning
direction, in other words, on cut faces perpendicular to the
face of the
panel.
Bedding
material shall be non-corrugated cardboard shims, placed
between the
test specimen and the loading surfaces.
New shims
shall be used for each test cube. Shim dimensions shall
be
approximately 3 in. 3 in. 1 / 16 in. (75 mm 75 mm 1.5 mm) thick.
Two thinner
shims making up the same total thickness may be used
in place of
a single shim.
Testing
machine minimum sensitivity and maximum loading rate
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C)
Abrasion (Erosion) Resistance
Testing
shall be in accordance with ASTM C704 and the following.
Fire to
1500°F (815°C)
Weigh the
specimens to the nearest 0.1 g.
Abrasion
shall be to an original free (not troweled, molded, or cut)
surface.
Use the
silicon carbide only one time before discarding.
From the
initial weight and volume, calculate the initial bulk density
to the
nearest 0.1 g/cm 3 . Calculate and report the amount of
refractory
lost by abrasion in cubic centimeters to the nearest 0.1 cc.
D)
Density
Density
shall be determined at room temperature on specimens
dried or
fired .
Testing
procedure shall be as follows:
measure specimen
dimensions to the nearest 0.02 in. (0.5 mm) and
determine
the specimen volume. Weigh the specimen to the
nearest
0.002 lb (1.0 g).
calculate
density by dividing weight by volume and report in units of
pounds per
cubic foot or kilograms per cubic meter.
E)
Permanent Linear Change (PLC)
General
Testing
shall be in accordance with ASTM C113 and the following.
The length
of each test specimen shall be measured to the
nearest
0.001 in. (0.025 mm) along the 9 in. (230 mm)
dimension at
each of the four edges of the specimen.
At room
temperature, determine the green refractory dimension
by measuring
the length of the specimen. For heat-setting
plastic
refractories the green dimension shall be determined
After
cooling to room temperature, measure the dried length of the
specimen and
then fire .
After
cooling to room temperature, measure the fired length of
specimen.
Green-to-dried
and Dried-to-fired PLC
a) General
Determine
the green-to-dried and dried-to-fired PLC as follows.
Report the
PLC as an average percent shrinkage in length for each
specimen to
± 0.05%.
b)
Green-to-dried
Determine
the green-to-dried length change of each of the four
edges of the
specimen and
Divide each
change by the green length of that edge. Average the
four values
to obtain the green-to-dried PLC of the specimen.
c)
Dried-to-fired
Determine
the dried-to-fired length change of each of the four
edges of the
specimen .
Divide each
change by the dried length of that edge. Average the
four values
to obtain the dried-to-fired PLC of the specimen.
d)
Workability Index
Testing
shall be in accordance with ASTM C181.
Each sample
shall consist of five specimen.
Pre-shipment
Refractory Qualification
a)
General
Refractories
to be installed by gunning, casting, or hand/ram
packing
shall be tested to ensure that they comply with specified
physical
property requirements .
Tested
physical properties shall be density, PLC, CCS or abrasion
resistance
(for abrasion resistant refractory), and workability index
(for plastic
refractory)
b) Subject
to owner`s approval,the contractor shall arrange for testing
at either an
independent laboratory or the manufacturer`s plant and
the direct
the work to assure that mixing techniques, water quality
and content,
ambient temperatures, mix temperatures, etc.,
represent
those needed for production installation.
The testing
party is responsible for conducting sampling, specimen
preparation,
testing, and documentation of results.
Pre-shipment
Refractory Qualification
c) For
plastic refractories, the manufacturer shall provide the actual
workability
index determined seven days after manufacture and the
minimum
acceptable workability index for suitable installation of
each plastic
refractory supplied.
Anchoring
components, including metallic anchors, ceramic anchor
attachments
and ceramic components including ceramic anchors,
and
tubesheet ferrules shall be certified according to the owner`s
criteria.
e) The
contractor shall inform the owner of testing arrangements and
timing so that
the owner may notify inspector to witness or spot
check the
testing.
When engaged
as a witness, the inspector shall select the container
be tested
and observe all sampling, specimen preparation, and
testing.
In cases
where an independent laboratory utilized or the contractor
assumes
complete accountability for testing results, inspector
participation
may be waived or reduced by the owner.
f) Based
upon the service designation, minimum testing frequency
shall be as
follows:
Erosion
service:- one sample per pallet or partial pallet from each
production
run.
Other
services:-one sample for three pallets or less from each
production
run.
When the
refractory is packaged in bags or other similar container,
the sampled
bag shall be randomly selected.
Forming
of Refractory Test Specimens
a) As
directed by the contractor and subject to approval by the owner,
the entire
selected container of refractory shall be mixed and test
specimens
formed using metal or plastic forms of the required
specimen
dimensions.
Alternatively,
samples may be made to larger dimensions and then
cut to the
required dimensions after 24-hour cure.
NOTE :-other
similar bulk containers, a representative sample of
appropriate
size shall be collected from each container at the time
of packaging
of the production run.
Forming
of Refractory Test Specimens
b) For cast
installations, refractory shall be cast in the same manner as
the
installation. For vibration cast installations, vibration shall be
used in the
forming of the test specimens.
c) For pump
cast installations, refractory shall be poured into forms.
d) For hand
packed installations, refractory shall be hand packed.
e) For
gunned installations, refractory shall be gunned to produce a
large panel.
Specimens
shall be cut from the central portion of the panel (i.e.
away from
the edges). Alternatively, specimens may be cast or hand
packed
subject to owner approval of a suitable, product specific
correlation
on the submitted product compliance datasheet to
gunned
properties supplied by the manufacturer.
f) Plastic
and other ramming refractories shall be formed using a
mallet or
handheld pneumatic rammer.
Specimen
formation using a pneumatic or ramming press, as
described by
ASTM C1054, is not permitted.
Application
Period
Refractory
shall be applied within four months of the initial
qualification
tests. If the initial qualification period is exceeded, the
refractory
batch may be requalified.
Requalification
permits usage for an additional three months after
each
requalification test.
Refractory
older than the manufacturer's recommended shelf life
shall not be
used.
Re-testing
In the event
a sample fails to meet specified requirements, it may
be retested
once. The retest shall be conducted using a new sample
representing
the same pallet(s) of the same batch of refractory as
the failed
sample.
Use the same
testing facility, testing procedure, inspector, and
inspection
methods.
A different
facility may be used, subject to the owner's approval.
If the
retest is unsuccessful, the refractory represented by the
sample(s)
shall not be used.
Qualification
of Installation Procedure and
Crew/Installers
Prior to
installation, the contractor shall demonstrate that the
specified
quality standards will be met using the material qualified
for the job,
including metal and organic fibers as applicable, and the
installation
method, equipment and personnel to be utilized for the
installation
work.
This shall
be done by simulating the installation and sampling and
testing the
applied materials as follows.
1.
Pneumatic Gunning
A test panel
shall be prepared by each nozzleman/gun operator
team for
each refractory being installed.
The panel
shall be inspected, sampled, and tested prior to
commencing
the actual installation.
A test panel
measuring 24 in. 24 in. (600 mm 600 mm) shall be
fabricated.
The panel
thickness, anchors and anchor pattern shall be in
accordance
with the actual installation job.
The test
panel forms shall be constructed with a removable back
and sides to
permit visual inspection of the installed castable.
The method
of anchor attachment shall permit removal of the
forms
without damage to the refractory or the anchors (e.g. use a
bolt through
the form). Interior surfaces of the forms shall be
coated with
a manufacturer approved releasing agent to facilitate
removal from
the refractory.
The test
panel shall be inclined 45 degrees above the horizontal and
supported on
a frame so that the panel's midpoint is approximately
6 ft (1.9 m)
above grade.
The
nozzleman/gun operator team shall demonstrate their abilities
by gunning
the test panel in this inclined position and testing.
At least 24
hours after completion of the panel, remove the forms
and inspect
the panel for voids, laminations, non-uniformities,
entrapped
rebound, or other flaws. The panel shall then be
sectioned or
broken and the exposed surfaces inspected for voids,
laminations,
non-uniformities, and rebound entrapment.
Test
specimens shall be cut from the center of each panel and
tested
physical property requirements for density, PLC, and CCS or,
where
applicable, abrasion resistance .
Alternatively,
with waived and measurements of the panel
dimensions
and weight used to determine the green density, which
is then
compared to a previously approved manufacturer supplied
value.
Panel
dimensions and weight shall be determined before the panel
is sectioned
or broken.
Satisfactory
examination and test results shall serve to qualify the
mixing and
installation procedures and the nozzleman/gun operator
teams.
The
nozzleman and gun operator shall not gun refractory materials
until they
are qualified.
2 Casting
A mock-up
shall be prepared by each applicator, for each mixing/
installation
procedure, and for each refractory being installed.
The mock-up
shall simulate the most difficult piece of the
installation
work for which the subject refractory and mixing/
installation
procedure will be used, or shall be of the size/shape
agreed to in
the documentation phase .
The mock-up
shall be inspected, sampled and tested prior to
commencing
the actual installation.
The mock-up
shall simulate forming and general installation
procedures,
including mixing, handling/delivery to the lining cavity
and
associated quality control requirements.
Installation
of refractory shall be in the same orientation to be used
for the
actual installation and shall simulate installation obstacles
(e.g. around
nozzle protrusions and beneath overhangs), and fit-up
tolerances
if work involves lining of sections to be fit-up at a later
date.
The
refractory thickness, anchors, and anchor pattern shall be in
accordance
with the actual installation job.
For
vibration cast installations, the mock-up shall demonstrate
the adequacy
of the vibration method, equipment and means of
vibrator
attachment.
For pouring
and pump cast installations, only vibration that will
be used in
the actual installation shall be allowed in the mock-up.
The forms
shall be constructed to permit removal for visual
inspection
of the refractory.
The method
of anchor attachment shall permit removal of the
forms
without damage to the anchors or the refractory.
Interior
surfaces of the forms shall be coated with a manufacturer
approved
release agent to facilitate removal from the applied
refractory.
Test
specimens (number, type, and preparation in accordance with
8.5) shall
be prepared using material sampled from the mixes
prepared for
casting the mock-up.
Specimens
shall be formed in molds using the same level of
agitation as
the mock-up. physical property requirements for density,
PLC, and CCS
or, where applicable, abrasion resistance .
Refractory
cast in the mock-up shall be cured for 12 hours minimum
prior to
stripping the forms.
Remove the
forms and visually inspect the refractory. The applied
lining shall
be homogeneous and free of voids or segregations and
shall meet
specified tolerances.
Satisfactory
examination and test results , shall serve to qualify the
applicators
and the mixing and installation procedures as well as
the mix
water levels.
The
applicator(s) shall not cast refractory linings until they are
qualified.
3. Thin
Layer Abrasion (Erosion) Resistant
Refractories
A test panel
12 in. 12 in. 3 / 4 in. or 1 in. (300 mm 300 mm 19 mm or
25 mm),
shall be packed by each applicator for each anchoring
system and
refractory being installed by the applicator.
The test
panel shall be inspected, sampled, and tested prior to
commencing
the actual installation.
Panel
thickness shall be the same as the lining to be installed.
Mixing and
application techniques (for example, pneumatic
ramming,
hand packing), orientation (sidewall or overhead), etc.,
shall be in
accordance with the actual installation job.
The hexmetal
or hexalt anchoring system(s) (as used for the actual
installation)
shall be attached to a backing plate in such a manner
that the
backing plate may be removed without damaging the
refractory
or the anchoring system.
For hexalt
systems, perimeter forms shall also be used to contain
the
refractory. The backing plate (and forms, if required) shall be
coated with
a manufacturer approved release agent to facilitate
removal from
the applied refractory.
Examination
of the panel may be performed immediately after
ramming, or
within 24 hours, as directed by the owner.
Remove the
backing plate and examine the panel from the backside.
The lining
shall be free of voids, incomplete filling of the anchoring
system and
inadequate compaction of the refractory.
Test
specimens shall be prepared using materials sampled from
the mixes
applied. Specimens shall be formed in molds , using the
same
placement method as the test panel.
Specimens
shall be tested in accordance with 8.1 for density, PLC,
and abrasion
resistance.
For each
batch of plastic refractories the workability index shall be
determined
and shall exceed the minimum acceptable value for
installation
.
Satisfactory
examination and test results shall serve to qualify the
applicator(s)
and the mixing and installation procedures, as well as
the mix
water levels.
The
applicator(s) shall not apply refractory linings until they are
qualified.
4. Thick
Layer Plastic Installations [Greater
Than 2 in.
(50 mm)]
A test panel
shall be pneumatically ram packed by each applicator
and for each
refractory being installed.
The test
panel shall be inspected, sampled, and tested prior to
commencing
the actual installation.
The test
panel shall be 24 in. 12 in. (600 mm 300 mm) with an
applied lining
thickness, anchors and anchor pattern in accordance
with the
actual installation job.
In the event
ceramic anchors are to be used in the construction,
panel shall
be large enough to properly demonstrate setting one
entire
ceramic anchor assembly.
The test
panel shall be constructed with removable back and sides
to permit
visual inspection of the installed refractory.
Anchors
shall be attached to the form in a manner that permits
removal of
the backing plate without damage to the refractory or
the
anchoring system.
Interior
surfaces of the backing plate and forms shall be coated
with a
manufacturer approved releasing agent to facilitate removal
from the
applied refractory.
Test panel
refractory shall be installed by pneumatic ramming in a
manner and
orientation (e.g. sidewall or overhead) simulating the
actual
installation.
After
refractory installation is completed, the test panel forms and
backing
plate shall be removed immediately and the refractory
examined
from the backside.
The
refractory shall be free of inadequate consolidation and voids.
The sample
shall be sectioned and examined to confirm that the
refractory
plastic is free of inadequate consolidation and/or voids
around the
anchors.
For plastic
refractories the workability index shall be determined
and shall
exceed the minimum acceptable value for installation
Satisfactory
results shall serve to qualify the equipment, techniques,
and
applicator.
The
applicator(s) shall not ram pack refractory materials until they
are
qualified.
1 .
Gunning (Wet or Dry Gun)
A minimum of
one sample of applied refractory shall be gunned by
each gunning
crew per material per shift using a wire mesh basket.
At least one
sample shall be prepared for each lined item.
The basket
shall be approximately 12 in. 12 in. (300 mm 300 mm)
and at least
4 in. (100 mm) deep but no greater than the installed
refractory
thickness.
The basket
shall be constructed of wire mesh with 1 / 2 in. (13 mm)
square
openings.
1 .
Gunning (Wet or Dry Gun) (contd...)
The basket
shall be supported on the wall where the lining
application
is proceeding, filled, and immediately removed.
All loose
refractory or rebound material shall be removed from the
area where
the basket was placed during sample preparation.
Production
samples shall remain in the same environment as
actual
production installation for the first 24 hours.
The required
test specimens shall be diamond saw-cut from the
refractory
applied in the basket.
1 .
Gunning (Wet or Dry Gun) (contd...)
Testing for
density, PLC, and CCS or, where applicable, abrasion
resistance.
Alternatively,
panels with enclosed sides may be used in place of
the wire
baskets if the panel dimensions are at least 18 in. X 18 in.
X 4 in. (450
mm x 450 mm x 100 mm), but no deeper than the
installed
refractory.
Test
specimens shall be cut from the center of the panels to avoid
inclusion of
rebound possibly trapped along the sides of the panels.
2.
Casting
A minimum of
one sample of the material being installed shall be
cast by each
mixing crew per material per shift.
At least one
sample shall be prepared for each lined item.
Test
specimens may be formed by casting directly into molds or by
casting into
larger forms and diamond saw cutting to the required
specimen
dimensions after curing.
Production
samples shall remain in the same environment as
actual
production installation for the first 24 hours.
Vibration
shall be used in casting of samples as applicable to
simulate
installation work.
Testing for
density, PLC, and CCS or , where applicable, abrasion
resistance.
Production
(As-installed) Refractory
3.
Plastics and Thin Layer Erosion Resistant Linings
A minimum of
one sample shall be packed by each applicator per
material per
shift.
At least one
sample shall be prepared for each lined item.
Test
specimens (abrasion plates and linear change bars) shall be
formed
directly from the refractory being installed using the
ramming
technique used for the installation.
The specimen
test for density, PLC, and CCS or, where applicable,
abrasion
resistance.
4.
Acceptance/Rejection Criteria
The average
physical properties of each sample of the as-installed
refractory
shall meet the criteria.
Inspector
verified records shall be kept by the contractor to identify
the samples
and the areas of the installed lining that they represent.
Failure to meet
the criteria shall be cause for rejection of the area
of the
refractory lining that the sample represents.
4.
Acceptance/Rejection Criteria (Contd...)
In the event
of disagreement over the installed refractory quality ,
core samples
may be taken from the questionable area of the
applied
lining and retested using the same test procedure and
evaluation
criteria.
If the re-
test is unsuccessful, the area of the lining represented by
the sample
shall be replaced.
The
contractor shall prepare records identifying and locating all
areas of
rejected and replaced lining (e.g. a map), the reason for the
rejection,
the means of repair, and the refractory used.
5 . Test
Specimen Preparation
Based on the
use designation the minimum number of refractory
specimens
for each sample shall be as follows.
The specimen
shall be cured as per specifications.
5 . Test
Specimen Preparation (contd...)
Hydraulic
bonded castable refractories shall be cured for a
minimum of
24 hours after placement.
During this
period the exposed surfaces of the refractory shall be
covered or
sealed with an impermeable coating or material.
Air-setting,
phosphate bonded castable refractories shall be air
cured,
uncovered, for a minimum of 24 hours after forming.
During this
period, the refractory shall be protected from moisture.
Heat-setting,
plastic refractories shall be allowed to air dry for a
minimum of
24 hours followed by oven drying in a form suitable for
drying
temperatures.
Once
refractory specimens have been fully cured, they shall be
removed from
the forms, and/or cut to required dimensions.
The
specimens shall be marked for identification with temperature
resistant
paint (to prevent burn-off during firing).
Specimens
shall be dried and fired as required by the testing
procedure
Oven drying
and firing shall be as follows. a)Oven dry: hold for 12
hours
minimum at 220°F to 230°F (104°C to 110°C) in a forced air,
convection
dryer. Heating to this level shall be in accordance with
manufacturer's
recommendations. Heat setting plastics shall be
oven dried
in the forms.
Oven fire:
heat at 300°F/h (170°C/h) maximum to 1500°F (815°C),
hold for
five hours at 1500°F (815°C); cool at 500°F/h (280°C/h)
maximum to
ambient.
Remove heat
setting plastics from the molds after oven drying and
before oven
firing.
For
heat-setting plastic refractories, see ASTM C1054 for
procedures
to remove from steel forms, drying and firing to avoid
handling
damage, skinning, bloating, and surface tears.
Installation/Execution
1.
Surface Preparation
Immediately
before refractory installation, all surfaces to be lined
shall be
cleaned to meet SSPC SP-7/NACE No. 4 standards for grit
blasting if
rust, weld slag, oil, dirt, or other foreign materials are
present on
the surface to lined.
If grit
blast cleaning is required, anchor leg coverings (if present)
shall be
removed before the grit blast cleaning.
After grit
blast cleaning, the surfaces to be lined shall be vacuum
cleaned to
remove all debris and new anchor leg coverings shall be
installed.
Water shall
not be used for washing unless it contains a suitable
inhibitor.
Surface
cleaning in accordance with SSPC SP-3 shall be acceptable
only for
limited areas such as spot grinding for repairs.
2. Water
Quality
Water used
for mixing in the refractory shall be potable.
The chloride
content of the water shall not exceed 200 ppm.
When
refractory is installed on stainless steel surfaces the chloride
content
shall not exceed 50 ppm.
NOTE The 50
ppm limit does not apply when the stainless steel is
limited to
the anchoring system or metal reinforcing fibers.
3.
Water-contaminated Refractory
Containers
of refractory exhibiting evidence of water contamination
shall be
discarded.
Any
individual container of refractory material containing hard
lumps (i.e.
cannot be easily broken by hand) shall be discarded.
4.
Preparation for Lining Installation
a)Timing
Refractory
installation shall not begin until completion of welding,
post weld
heat treatment, and pressure testing.
If the
refractory installation must take place before pressure
testing, all
pressure retaining weld seams shall remain unlined, i.e.
exposed to
the testing medium.
b) Lining
Penetrations
Structural
members, nozzle extensions, and other items within the
limits of
the lining shall be wrapped with 1 / 8 in. (3 mm) thickness
of a
nonabsorbent material to prevent moisture absorption from, or
bonding to,
the refractory lining. The wrapping shall be taped
smoothly
into place.
c)
Openings
Openings
shall be closed by means of sealed wood or metaljacketed plugs, slightly tapered
(smaller toward the shell), and of
such
dimensions to fit snuggly into the openings.
Surfaces of
the plugs shall be lightly coated with a manufacturer
approved
release agent or covered with plastic to prevent bonding
to the
refractory.
Plugs shall
not be removed from the openings or disturbed until at
least 24
hours after the refractory installation.
d)
Obstructions
Obstructions
(e.g. scaffolding) that could interfere with the
satisfactory
and continuous application of the refractory lining shall
be avoided.
Nozzle
Necks
Insulating
refractory in the nozzle neck shall be cast or hand packed
to within 1
in. (25 mm) of the inside of the shell or head to which it
is attached.
The remaining 1 in. (25 mm) shall be installed
monolithically
with the shell lining.
Voids or
spaces to be packed with ceramic fiber blanket insulation
(e.g.
annular space in nozzles equipped with inner sleeves) shall be
completed
before the installation of refractory.
Nozzles shall
be packed to a point flush with the inside face of the
shell. After
nozzle packing, the ceramic fiber density shall be at
least 8
lb/ft 3 (64 kg/m 3 ).
Ceramic
fiber blanket insulation shall be used only where
specifically
shown on the approved drawings.
Anchor
Preparation
Anchors
shall be cleaned of spatter and foreign materials before
refractory
is installed.
For
multilayer linings, anchors for the hot-face layer shall be
protected
and kept free of all backup refractory and foreign material
before
application of the hot-face layer.
If anchor
leg coverings are required, placement of the coverings
shall be
confirmed immediately before refractory placement.
e)
Equipment Cleaning
Mixers,
guns, conveyors, hoses, and all other equipment shall be
thoroughly
cleaned before use.
Equipment
shall be cleaned at each material change, shift change,
and more
often if buildup of castable takes place.
Cleaning is
required between each mix of phosphate-bonded
refractory.
For
non-phosphate bonded refractories, the cleaning interval shall
be such as
to prevent buildup of refractory materials on the mixer
internals
(including the drum). For low-moisture (low-cement)
mixes and
other refractories sensitive to water content, excess
water shall
be removed after each batch.
All tools
used in mixing, transporting, and applying the refractory
lining shall
be cleaned after each batch and kept free of all
deleterious
materials.
f) Site
The work
area shall be kept clean and protected to ensure that
lining
installation can proceed in an orderly manner without
incorporating
dirt, debris, rain, or other deleterious material into the
lining.
5.
Application Temperature
The temperature
of the air and shell at the installation site shall be
between 50°F
and 90°F (10°C and 32°C) during refractory
installation
and for 24 hours thereafter . Shading and enclosure
shall be
used to protect against extremes in temperature, sun
exposure, and
weather (e.g. wind and rain). 9.5.2 For cold weather
conditions,
heating and/or external insulation may be used to
maintain
temperatures above the minimum requirement.
For hot
weather conditions, shading, water spraying the unlined
surface
and/or air conditioning may be used to maintain
temperatures
below the maximum requirement.
Temperature
limits for refractory and mix water shall be in
accordance
with the manufacturer's requirements. In the absence
of
manufacturer's mix temperature limits, mix temperature shall be
between 60°F
and 80°F (15°C and 27°C).
6.
Gunning
a) Dry
Gunning
Pre-wet the
refractory by mixing with water prior to charging into
the gun.
Pre-wetting reduces dusting and segregation and helps
avoid
plugging in the feed hose. Optimum water addition, mixing
time, and
aging of the pre- wetted material shall be in accordance
with the
manuf the applicator qualification testing.
Gunning
equipment shall provide a smooth and continuous supply
of water and
material to the nozzle and shall not contribute to
laminations,
voids, rebound entrapment, or other deleterious effects
in the
installed lining.
Shotboards
or perpendicular edge cuts shall be used to terminate
work areas.
When stoppages greater than 20 minutes are
encountered,
or initial set is determined by the inspector, only full
thickness
lining shall be retained.
Begin
gunning at the lowest elevation, building up the lining
thickness
gradually over an area of not more than 10 ft 2 (1 m 2 ) to
full
thickness. Work in an upward direction to minimize the inclusion
of rebound.
Rebound material shall not be reused.
Downhand
gunning beyond 30 degrees below horizontal is
prohibited.
The refractory shall be placed by an alternative
placement
technique such as casting, hand packing, or repositioning
to avoid
downhand gunning.
Shotboard
height and/or depth gauges shall be used for thickness
measurement.
After gunning and confirmation of sufficient
coverage,
the refractory shall be trimmed (cut-back) in a timely
manner with
a serrated trowel or currycomb.
Cut-back
shall be performed when the surface is not damaged by
the cut-back
techniques (15 to 20 minutes after placement is typical)
, and before
initial set occurs.
Interrupted
build-up of lining thickness is not permitted after the
initial set,
defined as either the surface being exposed for more
than 20
minutes or becoming dry to the touch, whichever occurs
first.
b)Wet
Gunning
Wet gunning is
a unique installation procedure that requires
specialized
equipment and a different skill set than is common in
refractory
installation. When wet gunning is established as the more
suitable
installation technique the contractor, in conjunction with
the refractory
manufacturer, shall prepare a detailed installation
procedure,
and present it to the owner for approval.
All quality
control elements defined in this standard shall apply to
the
application of refractory by wet gunning.
Optimum
water addition at the mixer, mixing time, and the rate of
flocculating
agent addition shall be in ons and the applicator
qualification
testing.
Gunning
equipment shall provide a smooth and continuous supply
of material
and flocculating agent to the nozzle and shall not
contribute
to laminations, voids, or other deleterious effects in the
installed
lining.
Shotboards
or perpendicular edge cuts shall be used to terminate
work areas.
When stoppages greater than 20 minutes are
encountered,
or initial set is determined by the inspector, only full
thickness
lining shall be retained.
Begin
gunning at the lowest elevation, building up the lining
thickness
gradually over an area of not more than 10 ft 2 (1 m 2 ) to
full
thickness. Work in an upward direction.
Shot board
height and/or depth gauges shall be used for thickness
measurement.
After gunning and confirmation of sufficient
coverage,
the refractory shall be trimmed (cut-back) in a timely
manner with
a serrated trowel or currycomb.
Cut-back
shall be performed when the surface is not damaged by
the cut-back
techniques (15 to 20 minutes after placement is typical)
, and before
initial set occurs.
Interrupted
build-up of lining thickness is not permitted after the
initial set,
defined as either the surface being exposed for more
than 20
minutes or becoming dry to the touch, whichever occurs
first.
present it
to the owner for approval. All quality control elements
defined in
this standard shall apply to the application of refractory
by wet
gunning.
Optimum
water addition at the mixer, mixing time, and the rate of
flocculating
agent addition shall be in accordance with the
manufacturer`s
recommendations and the applicator qualification
testing.
Gunning
equipment shall provide a smooth and continuous supply
of material
and flocculating agent to the nozzle and shall not
contribute
to laminations, voids, or other deleterious effects in the
installed
lining.
Shotboards
or perpendicular edge cuts shall be used to terminate
work areas.
When stoppages greater than 20 minutes are
encountered,
or initial set is determined by the inspector, only full
thickness
lining shall be retained.
Begin
gunning at the lowest elevation, building up the lining
thickness
gradually over an area of not more than 10 ft 2 (1 m 2 ) to
full
thickness.
Work in an
upward direction.
Shot board
height and/or depth gauges shall be used for thickness
measurement.
After gunning and confirmation of sufficient
coverage,
the refractory shall be trimmed (cut-back) in a timely
manner with
a serrated trowel or currycomb.
Cut-back
shall be performed when the surface is not damaged by
the cut-back
techniques (15 to 20 minutes after placement is typical)
, and before
initial set occurs.
Interrupted
build-up of lining thickness is not permitted after the
initial set,
defined as either the surface being exposed for more
than 20
minutes or becoming dry to the touch, whichever occurs
first.
7
.Casting
Forming
shall be sufficiently strong to support the hydraulic head of
wet
refractory that will be retained and to resist any imposed
mechanical
loads, such as vibration. The forms shall be waterproof
and leak
free.
Dimensional
tolerances shall meet specified requirements.
A
manufacturer approved release agent shall be used to facilitate
stripping of
the forms.
Refractory
shall be mixed using the procedures, equipment, and
water levels
demonstrated in the material and applicator
qualification
tests.
For casting
and vibration casting, the mixer capacity shall be
sufficient
to facilitate placement with no more than 10 minutes
delay
between successive mix batches.
For pump
casting, mixer capacity shall be sufficient to allow for
continuous
pump operation without stops and starts to wait for
material.
For
vibration casting, two or more vibrators shall be mounted
externally
on the equipment or component to be lined.
Vibrators
shall be attached by strapping or a similar method; do not
attach
vibrators to nozzles, welded lugs, or other components.
Vibrators
shall have adequate force to move and consolidate the
material
being vibrated.
Each
vibrator shall be independently controlled to focus the
vibration
and prevent segregation due to over vibration.
Vibrator
selection, number, placement, and method of attachment
shall be
included in the installation procedure, approved by the
owner and
demonstrated in the mockup casting
For pouring
or pump casting, submersion vibrators or rodding may
be used to
aid refractory flow and filling of the formed enclosure.
Self-leveling
castables shall not be vibrated.
8.Thin
Layer Abrasion (Erosion) Resistant Linings
General
Chemical setting, erosion resistant refractories shall be
mixed in a
planetary mixer, such as those manufactured by Hobart .
The mixer
shall have stainless steel paddles and bowls. Tools shall
also be
stainless steel. Mixing shall be in strict accordance with the
manufacturer's
recommended procedures, using water levels
determined
during material and applicator qualification testing.
Refractory
shall be compacted using a handheld reciprocating
pneumatic
rammer, or a rubber mallet, and/or wood block as
demonstrated
in the applicator qualification tests.
During
placement, refractory shall be fully compacted in and around
the anchor
supports and, for hexalt anchoring systems, into the
previously
installed lining before it begins to set up, to form a
homogeneous
lining structure free of voids and laminations.
The
initially placed thickness shall be greater than the desired
thickness.
The full
depth of the refractory lining shall be placed in one
continuous
operation (e.g. the initial placement shall completely fill
the hexmetal
biscuit).
After
refractory consolidation, overfill shall be removed flush with
the tops of
the hexmetal or hexalt anchors using a trowel or curry
comb and
discarded.
The surface
shall be tamped, as necessary, to remove
imperfections
such as surface tearing and pull away defects.
Water
slicking of the lining surface is not permitted.
Water used
to clean tools shall be dried off prior to use of the tools
on the
refractory.
9)
Plastic Refractories
Plastic
refractories shall be installed at the manufacturer`s
recommended
consistaency.
Field water
addition or reconditioning is not permitted.
Reconditioning
shall be performed by the manufacturer under
controlled
plant conditions, and the reconditioned material shall be
fully
requalified
Plastic
refractory shall be removed from the container/plastic wrap
only when
ready for application.
Contents
shall be placed on a clean surface for cutting and/or
separating
precut slices.
The work
surface shall be cleaned and maintained to avoid
contaminating
fresh refractory with dried-out material from
previous
cutting or separating operations.
Under no
circumstances shall dry or crumbly material be installed.
10. Thick
Layer Plastic Linings
Plastic
refractories shall be installed at the manufacturer`s
recommended
consistency.
Field water
addition or reconditioning is not permitted.
Reconditioning
shall be performed by the manufacturer under
controlled
plant conditions, and the reconditioned material shall be
fully
requalified .
Plastic
refractory shall be removed from the container/plastic wrap
only when
ready for application.
Contents
shall be placed on a clean surface for cutting and/or
separating
precut slices.
The work
surface shall be cleaned and maintained to avoid
contaminating
fresh refractory with dried-out material from
previous
cutting or separating operations.
Under no
circumstances shall dry or crumbly material be installed.
Refractory
shall be ram packed in successive layers of undensified
slabs laid
perpendicular to the hot face using a reciprocating
pneumatic
rammer.
Each slab
shall be fully consolidated into a uniform mass with the
previously
placed slab, compacting the material in and around the
anchor
supports to form a homogeneous lining structure free of
voids and
laminations.
The
initially placed thickness shall be greater than the desired lining
thickness.
After
refractory consolidation, the lining shall be trimmed to the
desired
lining thickness using a trowel or currycomb.
Cutback
material may be reused if the material has not been
contaminated
and if workability characteristics are not diminished.
The trimmed
surface shall be tamped, as necessary, to remove
imperfections
such as surface tearing and pull away defects.
Water
slicking of the lining surface is not permitted.
Water used
to clean tools shall be dried off prior to use of the tools
on the
refractory.
After
plastic lining has been trimmed to proper thickness venting
shall be
carried out with a pointed rod.
Shrinkage
cracking shall be accommodated by the use of cut or
formed
control joints at a spacing recommended by the
manufacturer.
10 .
Metal Fiber Reinforcement
Metal fiber
reinforcement shall be used only when specified by the
owner .
Fiber
additions shall be uniformly dispersed in the castable, without
agglomeration.
Details of
fiber dimensions, concentration, and metallurgy shall be
specified in
the documentation
If metal
fiber is added during installation mixing the procedure shall
be as
follows: a)load castable into mixer and pre-mix;
add pre-wet
or mixing water;
using a
dispersing device, such as 1 / 2 in. (13 mm) hardware mesh,
sieve the
fibers into the castable with the mixer operating.
11
.Organic Fibers
Organic
fibers to facilitate moisture removal from refractory linings
during
dryout may be used with owner approval.
Fiber
addition shall be performed during manufacture of the
castable or
plastic refractory.
12.
Interruption of Application
If
application of hydraulic bonded or chemical setting refractory is
interrupted,
the refractory lining shall immediately be cut-back to
the shell
between anchors with a steel trowel.
Cutback
shall be made at a right angle to the shell or in accordance
to other
construction joint configuration as indicated on detail
drawings.and
at a location where the full refractory thickness has
already been
applied.
Discard all
material beyond the cut and material left in the gun,
hose,
containers, and/or mixer for more than 20 minutes.
Plate
surfaces shall be cleaned of all refractory lining materials.
Dislodged
anchor leg coverings shall be replaced.
During the
period of interruption in application, curing of the
refractory
lining already applied shall be
If
installation is halted for the day, all openings in the item being
lined shall
be covered, closed, and sealed.
Immediately
before resuming refractory application, the exposed
surface of
the refractory lining to which a bond must be made shall
be cleaned
of all loose refractory material, roughened, and
thoroughly
wetted with water or coated with a manufacturer
approved
membrane curing compound
Alternatively,
a bonding agent such as a weak phosphoric acid
solution or
phosphate-bonded mortar may be used.
If
application of heat-setting plastic refractory is interrupted for less
than 8
hours, pre-moistened cloth or burlap shall be used to keep
the mating
surface hydrated until work can progress.
13.
Curing
Curing shall
be in accordance with the manufacturer's
recommendation,
for a minimum of 24 hours at 50°F to 90°F (10°C
to 32°C),
before moving the piece, stripping the forms, or heating.
For chemical
setting refractories, the lining surface shall remain
uncovered
and free from contact with moisture during the curing
period.
For
hydraulic bonded castables, sealing and/or excess moisture
shall be
provided in accordance with one of the following methods.
Installation/Execution
•
a) Apply a
manufacturer approved membrane-type (non-reactive)
curing
compound to all exposed surfaces before the surface is dry
to the
touch. No part of the lining shall be allowed to air dry more
than 1 hour
prior to the application of curing compound.
The curing
compound shall be nonflammable, non-toxic, and contain
pigmentation
that allows for complete visual inspection of coverage.
The compound
shall burn off at a temperature of 150°F to 200°F
(65°C to
95°C).
b) Wetting
the exposed surfaces with a fine mist of water spray within
one hour of
installation and then at approximately 2-hour intervals,
such that
all surfaces shall be maintained wet to the touch
throughout
the curing period. Ensure that refractory components are
not washed
out or dislodged.
c) Covering
the exposed surfaces with polyethylene or a damp cloth
within one
hour of installation. The covering shall be in contact with,
but not
sticking to the refractory surface. If a damp cloth is used, it
shall be
maintained damp throughout the curing period.
Installation/Execution
•
•
d) No
coverage is required on formed surfaces as long as the forms are
retained for
the full 24-hour curing period.
Plastic
refractories do not require air curing. They shall be kept dry
and
protected from freezing conditions prior to the initial firing.
Manufacturer`s
recommendations shall be used to properly protect
phosphate
bonded plastics that will remain at ambient conditions
for
prolonged periods of time before heat curing.
14
.Repairs
a) General
Areas seemed
defective shall be repaired.
Sections of
the lining below the minimum thickness shall be cut out
entirely and
replaced.
Additional
material shall not be placed over previously applied
material to
build up to the required thickness.
In a
multilayer-lining, the hot face shall be removed without
removing or
disturbing the backup lining.
The
contractor shall prepare records identifying and locating all
repaired
areas and field joints (e.g. a map).
The record
shall include the reason for all repairs and the means of
repair along
with the refractory used.
b)Repair
Procedures
General
All proposed
materials and methods of repair shall be approved by
the owner
before the repair is made.
Immediately
before placement of the new refractory, the sound
refractory
material adjacent to the repair area shall be cleaned of
debris,
roughened, and completely prewetted with potable water,
membrane
curing compound, phosphate-bonded mortar, or a weak
phosphoric
acid.
Anchors and
shell shall be cleaned of refractory or other debris and
new anchor
leg coverings installed on the anchors where applicable.
If the
anchors or the attachment weld are damaged, the anchor
shall be
replaced in accordance with the original installation.
c)
Monolithic Lining
With the
exception of surface bubble defects , unacceptable
refractory
lining shall be cut at a right angle to the shell and laterally
to the
acceptable lining and removed. The shell shall not be
damaged.
Areas
removed for repair shall have at least one anchor completely
exposed. If
not, a new anchor shall be installed.
The
recommended area to be removed for repair shall be sufficient
to expose
three, noncontinuous anchors.
Corners
shall be rounded to a smooth, generous contour throughout
the depth of
the refractory.
When repair
of surface bubble defects is required, they shall be
repaired by
packing with a phosphate- bonded castable.
Metal fibers
shall not be used in this type of repair. The surface shall
be screed
flush with the adjacent refractory surface.
d) Thin
Erosion-resistant Lining
Defective
refractory in hexmetal lining shall require complete
removal and
replacement of all affected biscuits.
a) Dryout
Procedure
The
contractor shall develop a dryout procedure and submit it to the
owner for
approval.
The dryout s
dryout requirements and the requirements of this
standard. In
the absence of refractory manufacturer requirements.
The dryout
procedure shall include heat up/cool down rates for all
control
temperature indicators, location of and maximum
temperature
difference between temperature indicators, and shall
ensure
adequate flow of heated air over the entire refractory
surface.
The dryout
plan for complex vessels or vessel/duct/pipe systems
which involve
more than one burner, more than two flue gas exit
points or
eight or more thermocouples, shall be reviewed by an
engineer
experienced in dryout of complex systems.
Initial
heating of refractory linings shall be performed by temporary
equipment
such as portable burners or electric heating elements.
When
temporary heating devices are not practical, process heating
devices are
an acceptable alternative. Flame impingement and
radiant
heating are prohibited.
Cold wall
refractory lined components shall be dried out by heating
from the
refractory hot face only, in accordance with the approved
dryout
procedures.
Hot wall
refractory lined components shall be dried out by
application
of heat from either the inside or outside surface or by
placement within
an oven and heating from both sides, in
accordance
with the approved dryout procedures.
Heating
shall be controlled using temporary thermocouples to
monitor gas
temperatures throughout the lined area(s).
Thermocouples
shall be located within 1 / 2 in. (13 mm) of the
refractory
surface. Place thermocouples to detect any stagnant
area(s).
When
temporary thermocouples are not practical (e.g. dryout
performed as
part of startup), process thermocouples may be an
acceptable
alternative if they are capable of low temperature
Heating
rates shall be monitored by thermocouples closest to the
heat source.
The hold temperatures and durations shall be achieved
at all
thermocouples including those at gas exits of the installed
refractory.
Thermocouples
shall also be provided to protect design
temperature
limits of the unit and/or components
When
cool-down is included in the dryout work scope, cooling rates
shall not
exceed 100°F/h (56°C/h).
b) Dryout
Schedule
Generally it
is the provisions for determining safe and cost effective
dryout
schedules for conventional cement bonded castables.
Dryout is
the initial heating of castable refractory linings in order to
remove
retained water from within the refractory without adversely
affecting
its structure or physical properties.
The
procedure shall be efficient and provide for cost effective
execution
with minimal impact on the service factor of the process
unit in
which the refractory is installed.
c) Dryout
Index
Dryout is
described in schedules or procedures by heating rates,
target
temperatures, and hold times. For the purpose of this
standard,
these requirements are based upon gas temperatures at
the surface
of the lining that will see the greatest heat during
service.
Heat sources
and monitoring of gas temperatures affecting the
Refractory
products with dryout requirements differing from those
defined by
Table 5 shall be rated by the dryout index.
To provide a
comparative basis, the dryout index shall be defined as
the duration
time in hours that is required for initial heating from
50°F to
1300°F (10°C to 710°C), including recommended heating
rates and
holding times.
The Index
shall be based on single-layer linings 5 in. (127 mm) thick,
applied and
dried out in accordance with this standard.
Details of
actual heating rates and holding times within the overall
duration
defined by the dryout Index shall be determined prior to
installation
work
Modifications
to account for greater thickness and/or dual-layer
designs
shall be resolved at that time.
When drying
out a unit or vessel that has multiple refractories,
schedules
shall be based on the refractory or lining system that has
the longest
duration requirement for the maximum thickness at
each stage
of the dryout.
typical
dryout schedules for conventional castable refractories with
a density of
140 lb/ft 3 (2240 kg/m 3 ) or less is as follows.
Color Coding
for Metallic Anchors
1. Scope
The purpose
of this color coding guideline is to provide a method for
visual
identification of metallic anchors used in refractory linings by
a general
alloy classification.
Only
submerged anchors made of rods and castings shall be color
coded.
Hexmet al and hexalt anchors used in thin erosion-resistant
linings and
various designs of stud and washer anchors for ceramic
fiber
linings are not included in this specification as they can be best
identified
by stamping.
Identification
by this method is not a sub stitute for PMI (positive
material
identification) or other permanent manufacturer's
markings or
labeling t so, it is not intended that the color coding will
be resistant
to fading under all conditions including exposure to
high-temperature
operations.
The
principal purpose is to ensure identification of the alloy of the
anchor to
facilitate proper installation, inspection, and storage for
future
usage.
Many people
are lacking color discrimination.
Users of
this specification shall therefore ensure that personnel
involved in
color identification are able to discriminate colors.
Marking
Material Requirements
Paint shall
be used for the marking of color codes. Paint is specified
for
efficiency and cost effectiveness. Other marking materials, such
as dye, ink,
and colored labels, are permissible provided the marking
material
meets the durability, identification, chemistry, and safety
requirements
Paints used
for identification markings shall be durable and of
identifying
colors. Markings of the color-coded anchors shall not
fade when
stored indoors in a standard warehouse.
Paint
material shall be acrylic, alkyd modified acr ylic, or alkyd
enamels
capable of fast drying.
Paint shall
be free of cadmium, chromium, and lead. Also, the paint
shall not
contain copper, tin, zinc, chloride, sulfide, and other
undesirable
elements in any significant quantities.
The marking
requirements described in this color codification shall
b e applied
by the manufacturer (supplier or vendor as applicable)
and are
supplemental to any other marking and labeling standards
and
specifications under which the materials may be manufactured.
The
marking(s) shall be applied after completion of all anchor heat
treatments
(e.g. solution annealing).
Paints
contain solvents that pose safety and health hazards. Ther
efore, paint
shall be applied in fire protected, well ventilated areas.
Applicators
shall wear proper respirators and other safety gear.
The surface
to be color coded shall be cleaned and free of dirt,
loose scale,
and oil.
Marking for
color coding shall be by painting one or more stripes
onto the top
part of each anchor leg.
Each stripe
shall be of single solid color
For
two-component anchors, such as a V screwed or welded onto a
stud, each
part of the anchor shall be color coded.
Color Coding
for Metallic Anchors
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