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DESCRIPTION
Shipbuiding Quality Standard
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Editia 4 / Rev. 0
DMSQS
DAEWOO
MANGALIA
SHIPBUILDING
QUALITY
STANDARD
2010
PREFACE
This DAEWOO MANGALIA SHIPBUILDING QUALITY STANDADARD is to standardize the Quality Control practice for all kind of ships built in Daewoo Mangalia Heavy Industries S.A.
Basically, the Quality Control in process is emphasized as the major Quality Control Policy to minimize potential nonconformity at each production stage and to assure quality of final products, according to the documented requirements.
This booklet constists of the following four parts:
Part I. General procedure
Part II. Hull part
Part III. Outfitting & Machinery part
Part IV. Painting part
Generally, the standards stipulated in this booklet are applied to shipbuilding, but they may be applied for ship repairs and metallic constructions, too.
In case of conflict, however the requirements of the contract, building specification, approved drawings of agreed letters/ memorandum shall prevail over this Daewoo Mangalia Shipbuilding Quality Standard.
June, 2010
Quality Management Division
ONLY FOR INTERNAL USAGE OF DAEWOO-MANGALIA HEAVY INDUSTRIES S.A.
Part I. GENERAL PROCEDURE
C O N T E N T
I. GENERAL PROCEDURE FOR INSPECTION / TEST PAGE
1. Mandatory Inspection and Test ................................... 3
2. Request for Inspection/Test ....................................... 3
3. Cancellation, Postponement and Non-attenance .... 4
4. Inspection & Test Record ........................................... 4
5. Repair work ................................................................. 4
6. Other Quality Standard ................................................ 5
I. GENERAL PROCEDURE FOR INSPECTION 3
1. Mandatory Inspection and Test
(1) The inspection and test items listed herein are the fundamental inspection/witness points of the Client and the Classification Societies based on the Classification Society's rules.
(2) For those inspections and tests, which are not listed, however, the Client's representative and the Classification surveyor can have a free access to inspect all works during process unless additional staging or works stop is required.
(3) In principle, inspection/test is to be carried out in accordance with the Builder's working schedule. For smooth construction of the vessel, the inspection parties shall not refuse to inspect the parts designated by the Builder even if some minor works remain, which can be completed and subjected to inspection at later stage.
2. Request for Inspection/Test
(1) The Builder shall request the attendance of the Client's representative and the Classification surveyor for the relevant inspections/tests by a written Daily inspection schedule sheet, e-mail or facsimile.
(2) The request of inspections/tests is to be noticed according with internal procedure Process and Final Inspection DMPS 10.
(3) For painting inspection the notice will be given to the Clients representative in the morning of each inspection day due to variable and uncertain weather condition.
(4) For some reason, if the daily inspection schedule is delayed, the Builder shall notify the situation to the Client and the Classification office, as soon as possible.
(5) In the event of urgent inspection, the Builder shall notify and discuss with the Client's and the Classification Society representatives.
I. GENERAL PROCEDURE FOR INSPECTION 4
3. Inspection Cancellation, Postponement,
Non-attendance
(1) For any reason, if the inspection schedule is cancelled or postponed, the concerned parties are to be informed as soon as possible.
(2) If either the Client's representative or Classification surveyor fails to attend the inspection, it is to be deemed to waive his right and he shall accept the results of inspection performed by attended surveyor and/or Builder's Q.M inspector.
4. Inspection/Test Record
(1) The Builder shall submit the Inspection/Test Record forms containing the necessary information of the inspection items to the Client's representative and the Classification surveyor.
(2) Immediately after completion of the inspections/tests, the Client's representative and/or the Classification surveyor shall make confirmation signature on the inspection/test record, with the comments if any, and return to Builder's Q.M inspector.
(3) Inspection results shall be clearly judged as follows:
a) AA : Accepted in the existing condition b) QCC : Accepted with comments to be confirmed by Builder's Q.C. c) OWC (CLC): Accepted with comments to be confirmed by Owner (Class)
after correcting the comments given in writing d) NA : Not accepted, and subjected to re-inspection e) PP : Postponed due to inevitable reasons
(4) Copies of the major inspection and test records, including the quay and on-board test results, are to be submitted to the Clients representative and the Classification surveyor at the ship's delivery stage, according shipbuilding contract.
5. Repair work
(1) Repair work shall be basically carried out in accordance with builder's working practices and Classification Societies.
(2) When re-inspection is required, this will normally be included in the Daily-Inspection Schedule and shall follow the procedure described in the preceding paragraphs.
I. GENERAL PROCEDURE FOR INSPECTION 5
6. Other Quality Standard
(1) In general, other quality standard except various quality standard described in this booklet are applied to D.M.H.I.s technical standards and they are maintained in accordance with D.M.H.I.s documents control system.
(2) For technical field of D.M.H.I., the technical standards applied to the materials, components, design, and inspections are classified as follows:
a. Regulation Document defining a standard for a specific character, efficiency, dimension required on the producing product, part product, raw material and purchasing product and a term, abbreviations, symbols, units, system related to the technical fields.
b. Procedure Document defining the efficient and effective means, methods and sequence on the design, working, inspection, testing, purchasing and equipment of the engineering and manufacturing.
c. Working instruction Document describing a diagram, symbol and sentence after standardizing the job sequence, job method, standard time and job caution item for all of works performing in each working group.
REMARKS Marks of O, C and R in the list of inspection/test items mean as follows:
C : To be witnessed by the Classification surveyor. O : To be witnessed by the Client's representative. R : Test records and/or Classification certificate are required and
they are to be submitted to the Client's representative. Details for testing are to be specified in the On-board Test Procedure and
Mooring/Sea Trial Procedure which are separately prepared for each system testing.
The inspections of the Regulatory body or Government body specified in the contract or specifications are to be separately scheduled.
PART II. HULL PART
C O N T E N T
I. Major processes Page 1. Cutting/Forming process.............................................. 7
2. Assembly process................................................. 9
3. Erection process........................................................ 11
4. Welding process....................................................... 13
II. Categories of inspection and test items
1. Hull structure part. .............................................. 16
III. Quality standards 1. Material. ........................................................................ . 17
2. Gas cutting ................................................................... . 19
3. Fabrication ................................................................... 20
4. Assembly ...................................................................... 24
5. Alignment and finishing .............................................. 28
6. Unfairness .................................................................... 38
7. Surface finish condition .............................................. 39
8. Insert............................................................................ 46
9. Welding/Weld condition.............................................. 48
10. Grinding.................................................................... 53
11. Accuracy of hull form................................................ 55
12. Miscellaneous............................................................. 57
II. MAJOR PROCESSES
7
1. CUTTING/FORMING PROCESS
1.1. Control of Steel Materials
(1) When steel materials are transferred to shot blasting/priming process from steel stock area, the designated steel materials should be correctly selected and supplied by comparing the identification numbers of the steel materials with the Cutting Specification.
(2) After blasting/priming, the necessary identification such as project no., block no., grade and applied cutting station no. are marked down on the primed steel materials to identify the material.
(3) At the cutting stage, the part numbers of each cut steel piece are clearly marked according to the cutting information.
(4) Accuracy control of steel pieces should be maintained throughout the cutting process to minimize welding gaps.
(5) Following items are to be checked in this process:
Stage Check Point Remarks
Blasting/ Priming
a) Thickness and grade of plates, bars and shaped angles, etc.
b) Surface defects such as pitting or flaking
Random check
Marking
a) Precision of mould lines b) Drawing information c) Grade color marking:
1. Manual marking - White: mild steel - Yellow: high tensile steel
2. Auto marking - Black: mild/high tensile steel
Gas cutting
a) Condition of cutting surface: - Slag removal - Notch
b) Dimensions after cutting c) Primer touch-up condition
Random check
II. MAJOR PROCESSES
8
1.2. Forming
Bending Hot or cold bending of steel plates is to be performed according to the different technology requirements for materials of different properties and grades.
Mechanical bending Steel plates having cylindrical form are generally formed by a hydraulic press using the universal jigs with template tables.
Hot bending The plate having compound curves is firstly formed by the mechanical bending and finally formed by hot bending with line heating or spot heating.
The applied temperature in hot bending (maximum heating temperature on surface for line heating of plates forming) is controlled by means of temperature sensitive chalk (Tempil stick) according to the following table:
Steel type Cooling method Standard range (C) High tensile steel, conventional type t 50 mm
Water cooling just after heating Air cooling after heating
650 900
TMCP type AH32 EH32, AH36 EH36 Ceq > 0.38 %
After heating, air cooling and subsequent water cooling
900 (starting temp. of water cooling to be
under 5000 )
TMCP type AH DH grade Ceq 0.38 %
Water cooling just after heating, or air cooling 1000
TMCP type EH grade Ceq 0.38 %
Water cooling just after heating, or air cooling 900
Ceq is obtained from mill certificates Major check points
a) Heating temperature b) Accuracy of bending
II. MAJOR PROCESSES
9
2. ASSEMBLY PROCES
2.1. Sub-assembly
(1) For good access to block assembly work, structures having some size such as: floor, bulkhead, deck, side shell and large brackets, etc. are built up prior to block assembly.
(2) After completion of sub-assembly work, the sub-assembly is to be inspected by self-control, according self-control procedure. Then, necessary leakage tests on the fillet welds where water tightness is required are carried out by means of fillet air test, vacuum test or other proper methods.
2.2. Assembly
(1) Block assembly is a process of assembly/welding together with sub-assembled block and independent material pieces on the platform or jig, and automatic or semi-automatic welding is applicable alternatively according to shape of welding parts such as flat plate, curved plate, etc.
(2) The complicated blocks such as fore or aft parts of hull should be assembled with great care to acquire the acceptable accuracy of dimensions.
(3) After completion of the assembly work, the block is inspected only by builders inspector or in the presence of Classification Society surveyor and Clients representative. Then, necessary leakage tests on the fillet weld parts, where watertight is required, are carried out by means of fillet air test, vacuum test or other methods, which proved the tightness of welded part.
2.3. Major check points at assembly process
a) Shape of cutting surface b) Accuracy of dimensions for a single part c) Precision of 100 mark for fitting d) Alignment position of parts to the principal line/right angle e) Position of scallops or butt lines in way of bracket toe f) Collars or carlings as per drawing g) Position and size of lighting holes, drain holes, air holes, etc. h) Any damages caused by cutting i) Amount, direction of cutting allowances j) Removing unnecessary pieces k) Lapped-length of lap joint
II. MAJOR PROCESSES
10
l) Radius in way of squared hole m) Precision of centerline, water line, buttock line and/or control line n) Welding condition (refer to cap. 4 Welding process) o) Basic dimension as final p) Deformations q) Major components assembly: stern tube, rudder trunk r) Main engine bed plate settlement and smoothness
2.4. Fillet air test
Scope: it is used for plate thickness more than 12 mm and the fillet-welding seam performance has to follow the instruction from Tightness Plan. After completion of welding, compressed air is injected to the fillet weld joints through plug piece, and the inside air pressure should be checked with pressure gauge as shown in the following figure. Leakage can be detected by spraying a soapy water solution on the weld joints.
2.5. Vacuum leakage test
Scope: it is used for the leakage test of semiautomatic or manual butt-welding of side shell welding seam and is performed according to Tightness Plan instructions.
Air leakage test on fillet welding Plug Shell or deck
Air injection
Plug detail
Plug
Air Pressure gauge
Bulkhead
II. MAJOR PROCESSES
11
3. ERECTION PROCESS 3.1. Pre-erection / Erection
(1) The unit blocks are pre-erection/erection and welded together at the platform or in the dry dock with regular checks of the hull dimensions.
(2) After completion of pre-erection/erection work, the final inspection is carried out by Classification Society surveyor and Clients representative. Then, necessary leakage tests on the fillet weld parts where watertight is required, are carried out by means of fillet air test, vacuum test or other methods which are to prove the tightness of welded part.
(3) Welded joints of deck plates, bottom and side shell plates are subjected to NDE (Non-Destructive Examination) with radiographic test, ultrasonic flaw detector, etc. in accordance with NDE plan which is approved by the Classification Society.
(4) At pre-erection/erection stage, followings are to be carefully checked:
Check Point Remarks
a. Height and inclination of wooden block and its position
b. Amount of cocking down c. Center line and water line of each block d. Reference line and/or distance between
adjacent frames in way of block joint e. Arrangement of temporary pieces such as
strong backs f. Alignment accuracy of structural members g. Any structural nonconformity h. Center line of stern boss/gudgeon at stern
block i. Welding condition refer, to Para 4 Welding
Process j. Other necessary items
Wooden blocks are to be arranged to bear local compression.
3.2. Tank Testing
(1) All structural tanks are to be tested by air test or hydrostatic test. (2) The hydrostatic tests are to be carried out for the specified tanks
to confirm the structural strength in accordance with the Tank testing plan which is approved by the Classification Society.
II. MAJOR PROCESSES
12
(3) The hydrostatic test can be reduced for the succeeding sister vessels of same series.
(4) Before tank testing, the penetration pieces/piping concerned to the tests are to be completed, as far as possible.
(5) At tank testing, the following points are to be checked:
Kind of test Check point Remarks
Air test (Leakage test)
a. Internal pressure b. Leakage
Hydro Test (Strength test)
a. Height of water head b. Leakage (except the complete
parts at air test) c. Deformation of bulkhead
Attention to be paid to air pocket or air discharge route during filling water.
3.3. Staging Pieces and Lifting Lugs
(1) Staging pieces, lifting lugs used for erection of blocks are to be left in the position where they do not interfere with the function of the ship. However, those in the following locations are to be removed: a. Exposed parts of ship where they are likely to spoil the
appearance b. Passage where they may cause danger for ship's crew c. Other part designated by design as high stress area
(2) In case of removal of lifting lugs on flat decks, the finishing work by milling machine may be carried out after hand cutting in order to prevent paint damage under deck.
Details are mentioned in Quality Standards, Para. 7.2 Disposal of lifting lugs and staging hanger.
3.4. Temporary Access Opening
(1) When the temporary access openings are required on the shell plates, decks, bulkheads and tank top of double bottom for passages of hull work, for outfitting work or ventilation, they are to be applied according to Builder's Practice.
(2) The shape of the openings and the method of closing are mentioned in Quality Standards, Para. 8. Inserting.
II. MAJOR PROCESSES
13
4. WELDING PROCESS
4.1. General
(1) Since welding is an important work directly related to hull strength, it should be carefully controlled according to the welding procedure with the specified welding parameters. The repair methods for the welding gaps over the tolerance limit should be thoroughly controlled.
(2) When a new welding procedure is necessary to be applied, it shall be approved by the Classification Society.
4.2. Preparation before welding
(1) All parts to be welded are fitted with sufficient care to their accuracy. Edge preparation, angle of bevel, alignment of intercostals plates and fitting angles are controlled within the accuracy range specified in Quality Standard.
(2) Welding parts shall be free from grease, moisture, loose mill scale, excessive rust, harmful paint or other dirties.
(3) Tack welding is to be carried out after completion of preparation for welding.
4.3. Run-in, run-off plates (tap pieces)
(1) Run-in and run-off plates are to be installed at the start and at the end of butt joints in order to: stabilize the welding parameters and to avoid end craters and defects at the start and end of the weld, defects which will remain on these plates and not on the base material and cleanly removed on completion of the weld.
(2) Run-in and run-off plates must have the same thickness and edge preparation as the joint base material.
(3) Run-in and run-off plates dimensions for reference:
Details Dimensions Tolerances
Length (L) min.180 mm
3 mm Width (l) min. 100 mm
Thickness (t) Same thickness as base material
(4) For FCAW welding procedure the welding seam must start and finish for a minimum 30 mm on the run-in and run-off plates.
(5) For SAW / FGB welding procedure the welding seam must start and finish for a minimum 100 mm on the run-in and run-off plates.
II. MAJOR PROCESSES
14
4.4. Welding
(1) After confirming the above preparation, welding is carried out according to the welding procedure described in the Welding Procedure Specification to minimize deformation and residual stress.
(2) Electrodes, wire, welding method, welding condition shall be in accordance with Welding Procedure Specification and requirements of the Classification Society.
(3) After completion of welding, if necessary, the weld lines are touched up with a zinc epoxy primer to prevent rusting.
4.5. Inspection on weld parts
Following inspections are carried out to verify the quality of weld parts.
(1) Visual inspection (a) Visual inspection is carried out on all beads. Any found defect
parts is marked on the block and properly corrected. (b) The welding throat of fillet weld is to be checked by random
sampling. (2) Non-destructive examination
(a) Welded joints of strength deck plates, bottom and side shell plates are tested by the radiographic examination or ultrasonic flaw detector according to NDE plan which is approved by the Classification Society.
(b) Magnetic particle test or dye-penetration test is to be adopted for detecting the surface defect.
4.6. Major check points
a. Dimension and shape of edge preparation b. Alignment of welding parts c. Backing material (steel or ceramic material) d. Arrangement against deformation such as strong back e. Amount of preheating if specified f. Fitness of electrode and consumable used g. Welders qualification h. Gap before welding i. Weld throat in fillet weld/leg length in P.P., D.P., F.P. weld j. Uniformity of beads, intervals in intermittent welding k. Surface defects on weld such as crack, undercut, crater, etc.
II. MAJOR PROCESSES
15
l. Slag, porosity, inclusions m. Soundness of turn-round weld on such part as bracket toe n. Position of water-scallops and water stop hole o. Other necessary items
II. ITEMS OF INSPECTION/TEST
16
1. Hull Structure Part C O R Remarks
1.1. Block inspection for hull structure below main deck
| |
1.2. Block inspection for hull structure
above main deck |
1.3. Erection inspection for pre-erected lines
or tank space below main deck including accommodation
| |
1.4. Erection inspection for erection lines
or tank space below main deck | |
1.5. Erection inspection for erection lines or tank above main deck
|
1.6. Tank hydrostatic test according to
Tank testing plan | |
1.7. Air leakage test or vacuum test for
weld joint at tight boundary | |
1.8. Non-destructive examination according to
the Classification Societys rule | | NDE plan is made to show kinds and
locations of NDE items with Class. Societys approval
1.9. L B D measurement at ship center
and midship | | |
1.10. Draft mark inspection | |
1.11. Free-board mark inspection | Check at the marked condition
1.12. In water survey mark (for the applied
ship) inspection | Check at the marked condition
1.13. Bottom survey for launching | | | Check the closing of sea chest,
bottom plugs, etc.
1.14. Inclining experiment and
deadweight measurement | | |
III. QUALITY STANDARDS
17
1. MATERIAL
1.1. Surface flaw
1.1.1. Repair of defects
Defects are to be repaired by grinding or welding irrespective of their size and number. Repair by grinding may be carried out over the entire surface up to a depth as given by the under thickness tolerance of the product.
(1) Repair by grinding
The nominal thickness is not to be reduced by more than 7% or 3mm, whichever is the lesser. Each single ground area is not to exceed 0.25m2 and all ground areas do not exceed 2% of the total surface in question. The grounds areas must have smooth transitions to the surrounding surface. The defects or unacceptable imperfections are to be completely removed by grinding. Complete elimination of the defects is to be verified by a magnetic particle or dye penetrant test procedure at the Surveyors discretion.
(2) Repair by welding
Local defects, which cannot be repaired by grinding, may be repaired by chipping and/or grinding followed by welding in accordance with the qualified procedures approved by the Classification Society concerned. Any single welded area is not to exceed 0.125m2 and the sum of all areas shall not exceed 2% of the surface side in question. The distance between two welded areas shall not be less than their average width. The weld preparation should not reduce the thickness of the product below 80% of the nominal thickness. For occasional defects with depths exceeding the 80% limit, consideration of Classification Society will be necessary. The repair shall be carried out by qualified welders using an approved procedure for the appropriate steel grade. The electrodes shall be of low hydrogen type and must be dried in accordance with the manufacturers requirements and protected against rehumidification before and during welding
Acceptance limits for minor imperfection without remedies
Imperfection surface area ratio (%) 15~20% 5~15% 0~5%
t < 20 mm 0.2 mm 0.4 mm 0.5 mm20 mm t < 50 mm 0.2 mm 0.6 mm 0.7 mm
50 mm t 0.2 mm 0.7 mm 0.9 mm
III. QUALITY STANDARDS
18
1.2. Casting (Unit: mm)
Detail Correction/Remarks
Defect of cast steel In case the depth of defect is over 20% plate thickness, or over 25 mm in depth and 150 mm in length.
In case that cavity, crack and other injuries defect are found, after removing the defects, it is to be checked by dye penetration inspection, magnetic particle inspection or ultrasonic test and to be repaired by adequate method. * The extent of repair to be agreed with the
Classification Surveyor.
1.3. Lamination (Unit: mm)
Detail Correction/Remarks
Local limited lamination
(A)
(B)
1. In case of local limited lamination it may
be repaired by chipping and/or grinding followed by welding, as shown in (A).
NDE is to be done after repair.
2. In case where the local limited lamination
is near the plate surface, it is preferable to do the built-up welding as shown in (B).
NDE is to be done after repair.
3. Severe lamination is to be repaired by a local insert plate. The minim breath of insertion is: a) 1600 mm for shell and strength decks in
way of cruciform or T- joints b) 800 mm for shell, strength decks plating
and other primary members c) 300 mm for other structural members
The extent of repairs is to be agreed with
Classification Surveyor, case by case.
III. QUALITY STANDARDS 19
2. GAS CUTTING
2.1. Roughness for the gas cut edges (Unit: mm)
Section Detail Standard Range Tolerance Limits
Free edges Strength member 0,15 mm 0,3 mm Other 0,5 mm 1,0 mm
Welding edges Strength member 0,4 mm 0,8 mm Other 0,8 mm 1,5 mm
2.2. Dimensions (Unit: mm)
Detail Standard Range Tolerance Limits
Length of taper, l
l
d
l = 3d 0.5d l = 3d 1.0d
See also BV, Pt.B, Ch.12, Sec.1, 2.2.2.
III.QUALITY STANDARDS 20
3. FABRICATION
3.1. Flanged longitudinal and brackets (Unit: mm)
Detail Standard Range Tolerance Limits
Breadth of flange
a
b
compared to correct size
a: 3.0
b: 3.0 a: 5.0
b: 5.0
Angle between flange and web
compared to template
: 3 per 100 mm of a
: 5 per 100 mm of a
Straightness in plane of flange and web/cross tie
(Flange) (Web/cross-tie) 10
per 10 m in length 25
per 10 m in length
Sheer strake
Max. permissible angle shrinkage
a = 5
a
III.QUALITY STANDARDS 21
3.2.Built-up sections (girders, stiffeners, profiles)
(Unit: mm)
Detail Standard Range Tolerance Limits
Distortion of face plate
100
a3 +
a=design breadth 5d=design depth 5
100a5 +
Frames and longitudinal
: 1.5
per 100 mm of a
: 3
per 100 mm of a
Distortion of beam, frame, girder, stiffener
h = 200: a = 10 h = 500: a = 18
h 1000: a = 25 Intermediate values to be interpolated.
Distortion in plane of web and flange of built up longitudinal frame, transverse frame, girder and transverse web
10 mm
per span between primary members
25 mm
per 10 m in length
d
a
d
a
d
a
a
a a
h
III.QUALITY STANDARDS 22
3.3. Pillars, brackets and stiffeners (Unit: mm)
Detail Standard Range Tolerance Limits
Tripping bracket and small stiffener
a
t
Distortion at the part of free edge
2ta t
Pillar (between decks)
a
a 4 a 6
Cylindrical structure diameter (masts, posts, pillars, etc.)
D
200D
max. 5.0
150D
max. 7.5
Ovality of cylindrical structure
dmaxd min 0.02xdmax
d max
dmin
III.QUALITY STANDARDS 23
3.4. Corrugated bulkheads (Unit: mm)
Detail Standard Range Tolerance Limits
Mechanical bending
R
t
R 3t
2 t Material to be suitable for cold flanging (forming) and welding in way of radius
Depth of corrugation
D
D: 3.0 D: 6.0
Breadth of corrugation
A: 3.0
B: 3.0
A: 6.0
B: 6.0
Pitch and depth of swaged corrugated bulkhead compared with correct value (channelled plate)
A
h
A
h: 2.5
Where it is not aligned with other bulkheads
A: 6.0
Where it is aligned with other bulkheads
A: 2.0
h: 5.0
Where it is not aligned with other bulkheads
A: 9.0
Where it is aligned with other bulkheads
A: 3.0
III. QUALITY STANDARDS 24
4. ASSEMBLY
4.1. Accuracy of dimension (Unit: mm)
Detail StandardRange Tolerance
Limit Correction/Remarks
Flat plate for sub-assy and assembly
Length and breadth of flat plate 4.0 6.0
Squareness of sub-assembly (difference between diagonals in final marking)
5.0 10.0
Measured difference of diagonal length at final marking line
When the difference is over the limit, correct the final marking line
Distortion of flat plate 10.0 20.0
Measured on face plate of beam or girder
Deviation of interior members from skin plate
5.0 10.0
Excluding the case that interior members are connected by lapped joint
Skin plate Accuracy of this dimension
Frame, etc.
Curved plate assembly
Length and breadth of curved assy 4.0 8.0
Measured along the girth
Distortion of curved assembly 10.0 20.0
Measured on face of web floor or girder Correct the final marking of structural members when the distortion exceeds the limits
Squareness of assembly 10.0 15.0
Measured difference of diagonal length at final marking lines
Deviation of interior members from skin plate
5.0 10.0
III. QUALITY STANDARDS 25
(4.1. Accuracy of dimension) (Unit: mm)
Detail StandardRange Tolerance
Limit Correction/Remarks
Flat cubic block assy
Length and breadth 4.0 6.0
Squareness 5.0 10.0
Distortions 10.0 20.0
Deviation of interior members from skin plating
5.0 10.0
Twist
10.0
20.0
Before & after welding measured as follows:
Fr. L Fr. L
B. LA
B
C
D B. L
The points A, B and C are established in the same plane and then measured the deviation of the point D from that plane. When the deviation exceeds the limit, may re-assemble partially
Deviation between upper and lower plate
5.0 10.0
III. QUALITY STANDARDS 26
(4.1. Accuracy of dimension) (Unit: mm)
Detail StandardRange Tolerance
Limit Correction/Remarks
Curved cubic block assy from fore, aft area
Length and breadth 4.0 8.0 Measured along with girder
Twist of assembly 15.0 25.0 The same method as for the flat block assembly Distortion 10.0 20.0
Deviation between upper and lower plates
7.0 15.0 When the deviation exceeds the limit, may re-assemble partially
Squareness 10.0 15.0 Deviation of interior members from skin plate
5.0 10.0
4.2. Special sub-assembly (Unit: mm)
Detail StandardRange Tolerance
Limit Correction/Remarks
Block assy with stern frame
Distance between upper/lower gudgeon
a: 5 a: 10
d
c
b
a
(c):Twist of plane
including centreline
Distance between aft edge of boss and aft peak bulkhead
b: 5 b: 10
Twist of stern frame sub-assy c: 5 c: 10
Deviation of rudder from shaft centre line
d: 4 d: 8
Others The same as for curved plate block assembly
Rudder Twist of rudder plate 6 10
Correct or re-assemble partially
Others The same as for curved block assembly
III. QUALITY STANDARDS 27
(4.2. Special sub-assembly) (Unit: mm)
Detail StandardRange Tolerance
Limit Correction/Remarks
Main engine bed
Flatness of top plate of main engine bed
5 10
Breadth and length of top plate of main engine bed
4 6
4.3. Maximum heating temperature on surface for line heating
Steel type Cooling method Standard range
Conventional Process AH32 EH32 &
AH36 - EH36
TMCP type AH32 EH32 & AH36 - EH36
(Ceq > 0.38 %)
Water cooling just after heating
Under 650 C
Air cooling after heating
Under 900 C
Air cooling and subsequent water cooling after heating
Under 900 C (starting temperature of water cooling to be under 500 C )
TMCP type AH32 DH32 & AH36 DH36 (Ceq 0.38 %)
TMCP type EH32 & EH36 (Ceq 0.38 %)
Water cooling just after heating or air cooling Under 1000 C
Water cooling just after heating or air cooling Under 900 C
Note: Ceq = C + Mn + Cr + Mo + V + Ni + Cu (%) 6 5 15 Ceq = carbon equivalent TMCP = Thermomechanical controlled processing
III. QUALITY STANDARDS 28
5. ALIGNMENT AND FINISHING
5.1. Fitting accuracy of longitudinal (Unit: mm)
Detail Tolerance Limits Corrections
Butt welds, full penetration Web in T-, L- and flat bar longitudinal
t1 t2
a t1 t2
Strength member a 0.15 t1 (max. 3 mm)
{ Other members
a 0.2 t1 (max. 3 mm)
When a > 0.15t1 (strength member) and a > 0.2t1 (other member) or a > 3.0, additional welding smoothly or release and adjust the plate The plate to be released min. 30 a
Alignment of flange of T-longitudinal
Strength member a 0.04 b
(max. 8.0 mm)
When 0.04b < a 0.08b, max. 8 mm: grind corners to smooth taper over a distance min. L = 30 a When a > 0.08b, or 8 mm: Grind corners to smooth taper over a min. distance L = 50 a
Alignment of height of T-bar, L-angle bar or bulb
t
{ strength member a 0.15 t (max. 3 mm)
{ other members a 0.20 t (max. 3 mm)
Typical misalignment repair: When 3 mm < a 6 mm building up by welding When a > 6 mm release and adjust over minimum L= 50 x a (for strength structure) and L= 30 x a (for other members)
L
Flange (the height of web varies)
{ strength member a 0.2 t1 (max. 4 mm)
{ other members
a 0.3 t1 (max. 4 mm)
When a > 0.2t1 (strength member) and a > 0.3t1 (other members), additional welding smoothly or release and adjust the plate The plate is to be released min. 20a
III. QUALITY STANDARDS 29
5.2. Misalignment of butt joint (Unit: mm)
Detail Tolerance Limits Corrections
Alignment of butt welds
t1 t2
a t t1 2
{ strength membera 0.15 t1 (max. 4 mm)
{ other members a 0.2 t1 (max. 4 mm)
When a > 0.15 t1 (strength member) or a > 0.2 t1 (other member), additional welding smoothly
When a > 4 mm, release and adjust the plate
5.3. Fitting corrugated bulkheads (Unit: mm)
Detail Tolerance Limits Corrections
A
A
B
B
a t1/2 When a > t1/2 release and adjust the plate t1
t2a
Sec. A-A
t < t_1 2
t1
t2b
Sec. B-B
t < t_1 2
b t1
Where high stress area:
b t1/2
Where b exceeds the tolerance limits, release and adjust the plate
III. QUALITY STANDARDS 30
5.4. Alignment of fillet welds (Unit: mm)
Detail Tolerance Limits Corrections
Fitting of cruciform joint
t1 < t2
a) strength member and higher stress member
a t1/3
b) other a t1/2
Alternatively, heel line can be used to check the alignment
a) strength member and higher stress member
t1/3 < a t1/2 generally increase weld throat by 10% a > t1/2 release and adjust over a minimum of 50 x a
b) other
a > t1/2 - release and adjust over a minimum of 30 x a
Where t3 is less than t1, then t3 should be substituted for t1 in standard
5.5. Gap for overlap joint (Unit: mm)
a 2.0 mm max.=3.0 mm
When 3 mm < a 5 mm: the weld throat is to be increased as much as the increase of gap opening exceeding 3 mm
When a > 5 mm: release and re-aligned
5.6. Gap between beam and frame (Unit: mm)
s 2.0 max.= 5.0
When 3 mm < a 5 mm: the weld throat is to be increased as much as the increase of gap opening exceeding 3 mm When a > 5, release and adjust
a
a
t3t1 t2
at1/2
t2/2t1/2t2/2
t2
t3
t1
a
00
t2/2
t1/2 t1/2
t2/2
t3/2t3/2
III. QUALITY STANDARDS 31
5.7. Gap for fillet joint (Unit: mm)
Detail Tolerance Limits Corrections
Tee fillet
Weld throat < 4
s 2
Weld throat 4
s 3
(BV - Pt.B, Ch.12, Sec.1, al.4.2.5 limit = 4 mm)
When 3 < s 5 the weld throat is to be increased as much as the increase of gap opening is exceeding 3 mm When 5 < s 16 ( max. 1.5t )- chamfer to 30 ~ 45 and build up by welding , on one side, with or without ceramic backing or flat bar, grind and weld.
t
S
When s >16 or s > 1.5t, new plate is to be inserted; l 300 mm wide or repaired in accordance with the agreed procedure
Single bevel tee
t
S
Double bevel tee
t
S
s 3
s 3
When 3
III. QUALITY STANDARDS 32
5.8. Gap for brackets, frames, beams, stiffeners, etc. (Unit: mm)
Detail Tolerance Limits Corrections
Gap between bracket/ frame and stiffener
S
s 2.0 s max = 3.0
When 3 < s 5 mm, the weld throat is to be increased as much as the increase of gap opening exceeding 3 mm
When 5 < s 10 mm, chamfer 30 ~ 40 and build up with welding with backing
When s >10 mm, increase gap to 50 mm and fit collar plate tt1
l = (2t+25)mm min. 50 mm
5.9. Gap for butt joint (for FCAW) (Unit: mm)
Detail Standard Range Corrections
Flat/vertical position
R
S
t
= 50 5 R = 0 ~ 3 S = 4 ~ 8
When 8 < s 13 according to repair W.P.S. When 14 s 25 (or s 1.5 t)
Built up edge preparation on one or both side, grind, weld with back strip, remove backing strip, back gouge, back weld. When s > 25 or s > 1.5 t, new plate is to be inserted with min. 300 mm width or repaired in accordance with the agreed procedure.
t1
l
t
S
III. QUALITY STANDARDS 33
5.9. Gap for butt joint (for FCAW) (Unit: mm)
Detail Standard Range Tolerance
Limits Corrections
Horizontal position
R
S
= 3555R = 0 ~ 3 S = 6 2
s 8
When 8 < s 25 (max. 1.5 t)
When s > 25 or s >1.5 t, new plate is to be inserted with min. 300 mm width or repaired in accordance with the agreed procedure
5.10. Gap for butt joints (for S.A.W) (Unit: mm)
Detail Standard Range Tolerance
Limits Corrections
Flat position
S
S
S
6~12
6~
14
0 s 0.8 S = 2
When 0.8 < s 5, sealing bead is to be done When s > 5, re- fitting
5.11. Gap for butt joint (for E.G.W) (Unit: mm)
Detail Limits
s
t
f
t 12 t < 25 25 t 33 360 5 260 5 f 0 0 s 6 ~ 10 10 ~ 14
III. QUALITY STANDARDS 34
5.12. Gap for but joint (for F.G.B) (Unit: mm)
Detail Tolerance Limits
t 20 t 20 25 t 25 4505 5002
5.13. Height of bracket toe (Unit: mm)
Detail Tolerance Limits Corrections
h
Designed h 5
Cut Wire 0~3
0~1
0~1
t
III. QUALITY STANDARDS 35
5.14. Slot holes (Unit: mm)
Detail Tolerance Limits Corrections
Position of scallop
d 75
When d < 75, web plate to be cut between scallop and slot, and collar plate to be fitted
Or fit small collar over scallop Or fit collar plate over scallop
Distance between slot opening and hole
d
When d is not sufficient enough, correction shall be done in accordance with design practice
b (min.50 mm)
d
III. QUALITY STANDARDS 36
(5.14. Slot holes) (Unit: mm)
Detail Tolerance Limits Corrections
Gap around stiffener cut-out
S
SS
s 2.0 s max. = 3.0
When 3 < s 5 mm, weld throat to be increased as much as increase in gap opening exceeding 2 mm When 5 < s 10 mm, nib to be chamfered and built up by welding When s > 10 mm, cut off nib and fit the collar plate with same height as the nib
b
(20 mm b 50 mm)
III. QUALITY STANDARDS 37
5.15. Distance between welds (Unit: mm)
Detail Standard Range Tolerance
Limits Corrections
A. Distance between two butt welds
d
d 0
See also BV, Pt.B, Ch.12,
Sec.1, Sec.1.6.5.
B. Distance between butt weld and fillet weld
d
Strength members
d 10
Other d 0
When butt is welded first, the weld to be ground if fillet welds are on or closed to the welding seam See also GL rules, Ch. 1, Part 1, Sec. 19. 2.2. d is to be measured between toes of the welds
C. Scallops over welding seams
d
r
Strength members
d 5
Other d 0
When d < 5, enlarge scallop and ground smooth to obtain the distance between welds. d is to be measured between toes of the welds
D. Distance between two butt welds
For cut-outs d 30
For margin
plates d 300
150 See also GL rules, Ch. 1, Part 1, Sec. 19.2.2.
III.QUALITY STANDARDS 38
6. UNFAIRNESS
6.1. Fairness of plating between frames (Unit: mm)
Detail Standard Range Tolerance
Limits Remarks
Shell plate
Parallel part (Side & bottom shell)
4
8
L is one stiffener, frame, or longitudinal space
a (Deformation value)
L For interior plate of 8 mm or less, the tolerance is to be added to 2 mm
Fore and aft part 5
Tank top plate 4
Bulkhead
Long. bulkhead Trans. bulkhead Swash bulkhead
6
Strength deck
Parallel part (Between 0.6 L)
4 8
Fore and aft part 6 9
Covered part 7 9
Second deck
Bare part 6 8
Covered part 7 9
Fore-castle deck Poop deck
Bare part 4 8
Covered part 6 9
Super structure deck
Bare part 4 6
Covered part 7 9
House wall
Outside wall 4 6
Inside wall 6 8
Covered part 7 9
Interior member (web of girder, etc.) 5 7
Floor and girder of double bottom 5 8
III.QUALITY STANDARDS 39
6.2. Fairness of plating with frames (Unit: mm)
Detail Standard Range Tolerance
Limits Remarks
Shell plate Parallel part 2L/1000
3L/1000
To be measured between one transversal space ( min. L = 3m ) L = span of frame For bulkhead and outside shell, the basic length is about 5 m
Fore and aft part 3L/1000
4L/1000 Strength deck (excluding cross deck) and top plate of double bottom
3L/1000
4L/1000
Bulkheads 5L/1000
Accommodation above the strength deck and other
5L/1000
6L/1000
7. FURFACE FINISH CONDITION
7.1. Surface defects on plate (Unit: mm)
Detail Tolerance Limits Corrections
- Soft round - Sharp buckles and/or surface
flaws in plate
d 0.07 t (max. 3 mm)
1. When d 0.07 t (max. 3mm) defects are to be completely ground off
2. When d > 0.07 t or d > 3mm,
defects to ground off but not deeper than 0.2 t
Grinding cavity is to be welded with one layer of weld bead in excess and the weld is to be ground smoothly NDT will be applied
III.QUALITY STANDARDS 40
7.2. Disposal of lifting lugs and staging hangers (Unit: mm)
Location Removal Type Corrections
Exposed area
Exposed surface of shell, decks, living quarters
Outer surface of supper structure and funnel
Top/inside of deck store
X
X
Type X:
After removing piece, make it as shown Para. 7.1. Surface defects on plate)
Type :
The piece shall be cut above the beads, and sharp edges shall be ground. All around welding shall be done
Cutting line
Type :
The extruded part of the lapped type lug to be cut off and sharp edges shall be grounded
Type {:
The piece shall be remained as it is, but all around welding shall be done. (ordinary staging pieces, staging hanger, ordinary lifting lug, lashing eyes, rib-bracket and hand grips/steps)
Inside of accommodation
Behind ceiling and lining: Lower than ceiling depth Higher than ceiling depth
Without ceiling and lining Deck covering
{ X
Inside of engine room (including inside of engine casing and funnel), steering gear room, pump room, bosun store and other workshop
Deck without any covering Deck under grating floor Under up 2.0 m height above
passage floor. Other area
X or
{
Access trunk and chain locker X
Fresh water tank (SUS 316 material) Cofferdams, void space and others
{ {
In cargo tanks and ballast tanks
Details are as following Dwg.
30 m
m
III.QUALITY STANDARDS 41
(7.2. Disposal of lifting lug and staging hanger)
OIL TANKER (1)
MIDSHIP SECTION * : PERMANENT
III.QUALITY STANDARDS 42
(7.2. Disposal of lifting lug and staging hanger)
OIL TANKER (2)
MIDSHIP SECTION *: PERMANENT
III.QUALITY STANDARDS 43
(7.2. Disposal of lifting lug and staging hanger)
BULK CARRIER
MIDSHIP SECTION
III.QUALITY STANDARDS 44
(7.2. Disposal of lifting lug and staging hanger)
RO RO VESSEL
MIDSHIP SECTION
III.QUALITY STANDARDS 45
(7.2. Disposal of lifting lug and staging hanger)
CONTAINER SHIP
MIDSHIP SECTION BHD. ELEV.
III. QUALITY STANDARDS 46
8. INSERT
8.1. Direction of inserting (Unit: mm)
In the event that there are material defects, working mistakes, local damage, opening cut for access during production process, and deviation found in excess of Tolerance Limits, steel plate shall be remedied and corrected by inserting parts of plate.
Careful attention must be paid for strength member because the rolling direction of the inserted plate has to be the same like the adjacent plates.
8.2. Repair by insert plate (Unit: mm)
Note: L = 300 mm minimum B = 300 mm minimum R = 5t 100 mm minimum (1) seam with insert piece is to be welded first (2) original seam is to be released and welded over for a
minimum of 100 mm
8.3. Inserts of built up members (Unit: mm)
Fillet weld stiffener web/plate to be released over min. d = 150 mm
Insert 1
4
2
3min. 300
150150
4
3
Weld sequence: c d e f Web butt weld scallop to be filled during final pass (f)
III. QUALITY STANDARDS 47
8.4. Insert of holes (Unit: mm)
Insert of holes is to be made according to type 1) Spigot pieces - Class
approval for high stress area - 2) and 3) After tack welding it should be kept welding sequence as follows.
1) R = 5 plate thick. (Min 100 mm) 2) Weld sequence: c d e f
1) Lap type 2) Insert type 1 3) Insert type 2
Detail Method Remarks
Skin plate (Shell), deck, longitudinal bulkhead, transverse bulkhead and high stress area
Insert type
For holes less than 200 mm diameter, increase size of hole to 300 mm and fit insert plate type 1
For strength members, the open hole has to be cut at min 75 mm diameter, fit and weld spigot piece
Holes more than 200 mm diameter, inserting as the hole is or fit lap plate
In case that the insert type 2 is applied, hole width is to be not less that 300 mm
Others Lap type
Holes up to 25 mm diameter in W.T. or area of stress concentration (near toes of brackets, etc.)
To be countersunk and closed by welding or welded double/reinforcement is to be fitted
Dmin = 300 mm
D
min. 50 mm
t1t
t = t1
D
Dmin = 300 mmFor circular insert
1 4
3 2
4
23
1
Rt
t1
DG
l
1/2t t1 t Dmin = 75 mm
= 300 - 400G = 4 ~ 6 mm
III. QUALITY STANDARDS 48
9. WELDING/WELD CONDITION
9.1. Shape of Bead (Unit: mm)
Detail Tolerance Limits Corrections
Butt weld toe angle Flank angle -
B: not defined 60
h 6 limit 90
Weld up
Grind off
Where > 90, it is to be repaired by grinding and welding, where necessary to make 90
Butt weld undercut
a
Strength member a 0.5
Other member
a 0.8
For strength member where 0.5 < a 1mm, and for other where 0.8< a 1mm, undercut to be ground smooth (locally only) or to be fitted by welding Where a > 1, undercut to be filled by welding The filled up welding shall not be ground off Minimum short bead H.T. (Ceq > 0.36%) length 50 mmGrade E of mild steel length 30 mmH.T. (Ceq 0.36%) length 30 mm
Fillet weld undercut
a
a 0.8
Weaving width:
SMAW (manual welding) diameter of electrode 3.5 FCAW (CO2 weld) max. 23
III. QUALITY STANDARDS 49
9.2. Welding remedial by short bead (Unit: mm)
Detail Remedial standard Remarks
Short bead for remedying scar
(scratch)
a) HT steel, Cast steel, TMCP type HT steel (Ceq >
0.36%) and Low temp steel (Ceq > 0.36%)
Length of short bead 50 mm
b) Grade E of mild steel
Length of short bead 30 mm
c) TMCP type HT steel (Ceq
0.36%) and Low temp steel (Ceq 0.36%)
Length of short bead 10 mm
o For casting steel, preheating necessary as per WPS
o Where short bead is necessary, preheating shall be done up to 100 25C
o In case short bead is made erroneously, it shall be removed by grinding and rewelded
For base metal, which could be affected by risk of cold cracking, the short bead part to be ground off 2 to 4 mm in depth and rewelded
Remedying weld bead
a) HT steel, Cast steel, TMCP type HT steel (Ceq > 0.36%) and Low temp steel (Ceq > 0.36%)
Length of short bead 50 mm
b) Grade E of mild steel
Length of short bead 30 mm
c) TMCP type HT steel (Ceq
0.36%) and Low temp steel (Ceq 0.36%)
Length of short bead 30 mm
III. QUALITY STANDARDS 50
9.3. Temperature required preheating
{ High strength steels
(Conventional type)
Air temperature
T 0C
Preheating level is to be applied unless the approved welding procedure specifies a higher level
{ Normal
strength steels
T -5C
9.4. Repair of arc strike
{ High Tensile
steel { Cast steel { Grade E of mild
steel
Not permitted
If arc strike is made erroneously, the hardened zone shall be removed by grinding
III. QUALITY STANDARDS 51
9.5. Shape of fillet welds (Unit: mm)
Detail Corrections Remarks
L: Leg length T: Throat thick
L 0.9 Design figure * T 0.9 Design figure
In case the length L is less than the Tolerance Limits, the weld is to be increased * Undersize portion shall not exceed 10% of weld length in a span
9.6. Weld surface repair (Unit: mm)
Detail Corrections Remarks
Spatter
1. Remove spatter observed before
blasting with scraper or chipping hammer, etc.
2. For spatter observed after blasting:
1) Remove with a chipping hammer, scraper, etc.
2) For spatter not easily removable with a chipping hammer, scraper, etc., grinding the sharp angle of spatter to make it obtuse
Generally no grinding is applied on weld surface
III. QUALITY STANDARDS 52
(9.6. Weld surface repair) (Unit: mm)
Detail Corrections Remarks
Over lap
In case is less than 90, it shall be repaired by suitable method to make > 90
Short bead is carefully avoided for high tensile steel
Weld defect
The following defects are to be removed by suitable method: Example:
1) Crack 2) Clustered porosity 3) Short bead 4) Arc strike 5) Hydrogen porosity
Weld defect as crack is to be examined by non-destructive examination (Magnetic Particle) before repair the welding
III.QUALITY STANDARDS 53
10. GRINDING (Unit: mm)
Detail Grinding Standard Remarks
Cleaning of the weld groove
1) As-cut surface or as-rolled surface is
acceptable for all welding 2) As rusted surface is acceptable for
manual welding but not acceptable for automatic welding
3) As-gouged surface is acceptable for A
to D grade and AH grade steel: - Slag, crack, incomplete penetration
and clustered porosity on the gouged surface are to be completely removed
- Gouged burrs are to be completely removed
Thick rusted scale is to be removed by grinding or brushing
Gas cut edge of high stress members
The high stress members mean the openings of strength deck and the free edge of sheer strake
Grind to 1~ 2 C
1 ~ 2 mm
Detail
Where otherwise noted in the drawing, it is to be done as per the drawing
III.QUALITY STANDARDS 54
10. GRINDING (Gas cut edge general) (Unit: mm)
Area Detail Standard
A.
Painting area
OPTION 1 In accordance with building
specification
Grind to 1C
0,5 - 1 mm
450 150
Legend: 1C
OPTION 2 In accordance with building
specification
Grind to 2C
1 ~ 2 mm
450 150
Legend: 2C
OPTION 3 In accordance with building specification
Legend: 3 pass grinding
B.
Painting area (non- exposed area and general)
Machinery space Cargo holds
(B/C, Container, Ro-Ro)
No grinding
C.
Others (incl. no-painting
area)
Except above A and B
No grinding
A b o u t 2 .0 m m
Abo
ut 2
.0 m
m S m a l l b u r r m a y b e re m a in e d a f te r g r in d in g
3
2 1
III.QUALITY STANDARDS 55
11. ACCURACY OF HULL FORM
11.1. Principal dimension (Unit: mm)
Detail Standard
Range Tolerance
Limits Correction/Remarks
Length
Length between perpendiculars
L/1000 where L is
in mm Not defined Applied to ship of 100 m length and above
Breadth
Moulded breadth
(midship)
B/1000 where B is
in mm
Not defined
Applied to ships of 15m breadth and above Measured on the upper deck
Depth Moulded depth
(midship)
D/1000
where D is in mm
Not defined
Applied to ship of 10 m depth and above Measured up to the upper deck
III.QUALITY STANDARDS 56
11.2. Deformation of hull form (Unit: mm)
Detail Standard
Range Tolerance
Limits Correction/Remarks
Flatness of keel
Deformation for the whole length 50 per 100 m
Not defined
Up (+) and down (-) per 100 m against the line of the keel sighting
Deformation for the distance between two adjacent bulkheads 15 Not defined
Sighting by the theodolite or laser Local unfairness is referred to section 7 Unfairness
Cocking
Cocking of fore-body
F.P. Bhd.
F.P.
b. line
30
Not defined
Up (+) and down (-) against the check line of the keel at the fore most frame on the flat part of the keel
Cocking-up of aft-body
20
Not defined
Up (+) and down (-) against the check line of the keel at the aft perpendicular
Rise of floor amidships
15 Not defined
The height of the lower turn of the bilge compared with the planned height Measured from the design line
III.QUALITY STANDARDS 57
12. MISCELLANEOUS
12.1. Draft mark (Unit: mm)
Detail Standard Range Tolerance
Limits Remarks
In regard to the template
1.0 2.0
12.2. Freeboard mark (Unit: mm)
Detail Standard Range Tolerance
Limits Remarks
In regard to the template
0.5 1.0
12.3. Opening of entrance (Unit: mm)
Detail Standard Range Tolerance
Limits Remarks
Opening of steel door
Breadth and height Sill height Deformation
4
0 ~ 15
2/1000
7
-10 ~ +30
3/1000
Opening of deck
Breadth Length
2
3 3
5
PART III. OUTFITTING & MACHINERY PART
C O N T E N T I. MAJOR PROCESSES Page
1. Piping Processes ....................................................... 59 2. Pre-outfitting Process ............................................... 65 3. Machinery Outfitting Process .................................... 66 4. Electric Outfitting Process ........................................ 76
II. CATEGORIES OF INSPECTION AND TEST ITEMS 1. Hull Outfitting Part ....................................................... 78 2. Machinery Part ............................................................. 81 3. Piping Part ................................................................... 86 4. Electric Part ................................................................. 88 5. Remote Control/Automation Part ................................ 93
III. QUALITY STANDARDS
1. Main machinery ............................................................ 94 2. Auxiliary machinery ..................................................... 97 3. Piping .......................................................................... 102 4. Sheet metal outfitting .................................................. 116
I. MAJOR PROCESS
59
1. PIPING PROCESS
1.1. Pipe bending
(1) As a standard for steel and non ferrous pipes, bending are to be carried out by the cold bending machine having the bending radius of approximately 2 3 times of the outside diameter of the pipe and by the hot bending machine having the bending radius of 2,5 3 times of the outside diameter of the pipe.
(2) Elliptically, swells and rumples caused by bending of pipes shall not exceed the quality standard ranges of Para.3.2.
(3) In case the regular pipe bending as mentioned above cant be applied due to following reasons, commercial bent pipes are to be used:
a) When the capacity of existing bending machine is not enough to bend b) When the non-standard bending radius is necessary to facilitate
the piping arrangement (4) The commercial bend pipe should be of seam or seamless for general
piping system for those of nominal dia. 200 mm below, and the fabricated pieces may be commonly used for those of nominal dia. 200 mm and above, if there is no specific requirements from the Classification Society.
(5) In case the arrangement is difficult to use the commercial bend pieces, then the miter welding pipe having a radius approximately equal to the nominal pipe diameter are to be applied. However the miter welding method is to be applied only to low pressure and large size pipes such as exhaust gas, seawater, exhaust steam piping, etc.
(6) For adjustment of pipe alignment at pipe installation stage, hot process could be restrictively applied.
1.2. Finishing of Weld Parts after Pipe Fabrication
Weld beads on inside surface of fabricated pipes shall be finished to suit the intended purpose of the respective piping system in accordance with the following three grades:
< GRADE A >
(1) Welded beads of pipe insides shall be finished smoothly and welding spatters and slag shall be removed.
(2) This grade applies to lubricating oil pipes, hydraulic oil pipes, fuel oil injection pipes after the 2nd filter for main diesel engine, turbine steam pipes and for synthetic rubber or plastic lined pipes.
I. MAJOR PROCESS
60
< GRADE B >
(1) Welding spatters and slag shall be removed and welded beads shall be cleaned.
(2) This grade applies to power steam pipes, turbine exhaust pipes, fuel oil service pipes, drinking water pipes, nozzle cooling pipes, feed water pipes, condensate water pipes, sea water cooling pipes, compressed air pipes, tank cleaning pipes and vent pipe for cargo tanks.
< GRADE C >
(1) Welded beads of pipe insides may not be finished.
(2) This grade applies to all other pipes which are not specified in GRADE A and GRADE B and open ended lines like drains, overflows, vents and boiler escape pipes.
1.3. Flange Fitting in Shop
When the pipe is inserted into the flange for joining, inserting depth should be controlled so that the welding bead will not overpass the flange face. The flange face is usually not finished by grinding, but welding spatters and slag on flange face shall be removed.
1.4. Pipe Joints
In general, a plastic thin sheet, plastic covers or other methods protect the free ends of the pipes.
In general, pipe joints are grouped as follows by their use:
1.4.1. Sleeve Joints and Butt Joints
(1) Generally, sleeve welded joints and butt welded joints are to be used for permanent joints in spaces such as tanks, cargo holds, cofferdams, void spaces, ducts, store spaces, accommodation spaces, hatch side spaces, etc., unless other joints are specified in the building specification.
(2) Butt welded joints may be applied to the commercial bent piece and T-piece.
1.4.2. Flange Joints and Union Joints
(1) Flange joints, union joints and other separable joints are to be used in the engine room, pump room, steering gear room, and other machinery spaces and on exposed decks for facilitating to remove the pipes whenever required.
I. MAJOR PROCESS
61
(2) Flanges or screwed union joints are to be used at the connection parts to all pipe fittings, machinery and equipment for maintenance or overhaul purpose.
1.4.3. Joints for Non-Ferrous Pipes
Pipe joints for non-ferrous pipes are to be applied similar to those for steel pipes. However for joining of plastic pipes, it has to be followed the Classification Society's requirements unless otherwise specified in the Specifications.
1.4.4. Joint Gaskets
Universal heat and oil resisting non-asbestos joint sheets shall be used generally in all piping systems.
1.5. Adjusting Pipes
(1) Adjusting pipes are to be generally used for connections between pipe and equipment or pipes already fitted on the blocks. The flanges of the adjusting pipes may be welded on board. In general, the adjusting pipes shall be finally galvanized after on board adjusting.
(2) The flange angle of the adjusting pipe could be sloped in order to make parallel the connecting flange faces.
(3) For correction of alignment for pipe connection, the spot heating process could be applied. However, this method cannot be applied to lubricating and hydraulic oil pipes.
1.6. Pipe Galvanizing
(1) The galvanizing shall be carried out after fabrication of pipes. However, if the welding work is inevitably carried out on the galvanized pieces during installation process, such as in the following cases, the external surface of the welded parts are to be touched up with zinc rich epoxy primer:
a) Socket welded joint or welded sleeve joint fabricated on board
b) Middle flanges of penetrating piece adjusted on board c) Anchoring piece welded on galvanized pipes after adjusting on
board (except sea water handling system) d) Flange joint adjusted on board (except sea water handling system)
(2) Internal surface of the welded part of flange joints adjusted on board shall be touched up with epoxy paint instead of zinc solution paint for better resistance against corrosion as far as practicable.
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1.7. Pipe Pickling by Acid and Oiling
(1) After fabrication of the steel pipes, acid cleaning shall be carried out before installation on board. For the steel pipes applying the polyethylene lining, blasting shall be carried out instead of acid cleaning before lining.
(2) Phosphate treatment after acid cleaning shall be processed for the steel pipes except for the pipes applying galvanizing or polyethylene lining.
(3) For proper prevention from rusting, following pipes shall be blown out with compressed air and dried before installation on board:
a) Lubrication oil pipes except drain pipes and air vent pipes b) Fuel oil service pipes from main engine, diesel generators and
auxiliary boiler. c) Hydraulic oil steel pipes
(4) Exposed flanges of unfinished piping installed on board shall be protected by means of end caps (plugs or blanks) and precaution shall be taken to ensure that the pipes remain sealed after cleaning.
1.8. Bolts for Pipe Flange Joint
(1) Hexagon head bolts and nuts of galvanized steel are to be generally used for pipe flange joints. Non-galvanized bolts and nuts are to be generally used in oil tanks.
(2) The length of bolts protruding beyond the nuts after tightening is to be between zero and bolt diameter.
1.9. Pipe Supports
(1) In general, steel supports and U-type bolts are to be applied to pipe lines at suitable intervals. Pipe supports for non-ferrous are to be lined with copper, brass or lead plate, plastic or synthetic rubber.
(2) The length of the screw part of the U-type bolts protruding beyond the nuts after tightening is to be between zero and one time of the bolt diameter.
1.10. Hydrostatic/Leakage Test of Piping
The piping systems are to be hydrostatic/leakage tested using suitable medium at the completion of the installation to check the strength and/or leakage in the system.
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1.11. Non-destructive Test for Welded Joint of Piping
The following non-destructive tests shall be applied to welded joints designated by the Classification Society according to rules and/or any other parts where mutually agreed upon:
a) Radiographic test (RT) b) Magnetic particle inspection (MPI) c) Ultrasonic Test (UT) d) Penetration Test (PT)
1.12. Air Conditioning and Refrigeration Plant
After install of the refrigerant piping, the pressure and vacuum test to be carried out according to following conditions:
(1) Pressure Test
Division Test Pressure (Kg/cm2. G) Allowable Pressure
Drop (kg/cm2. G) Test Duration
(Hours) High Pressure side 22 Less than
0.35 4 Low Pressure side 15
The final pressure drop to be calculated as follows: P0 P (T0/T) 0.35 (kg/cm2. G)
T0 : The 1st Temperature T : The last Temperature P0 : The 1st Pressure P : The last Pressure (2) Vacuum Test
Vacuum Pressure (mmHg)
Allowable Pressure Drop (mmHg)
Test Duration (Hours)
740 Less than 1 12
1.13. Earth Bonding
The gasket flange joints and the connected area between the pipe and hull structure for the following piping system shall be electrically bonded with tooth washer, bonding wire or bonding plate. The detail bonding method shall be followed to the approved design practice. a) Cargo oil pipe b) Inert gas pipe c) Tank cleaning system pipe d) Vapor emissions line e) Electrical cable main pipe f) Fuel gas line
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1.14. Flushing/Cleaning of Piping System
(1) Following piping systems are to be flushed /cleaned after completion of the piping system on board.
(2) For flushing by oil, the temporary filters and magnets are to be fitted in strainers.
(3) The flushing is to be completed when the filters are maintained constantly in clean condition for over two hours of flushing.
Piping System applied Flushing/cleaning method
Lub. oil piping
M/E L.O. System oil
M/E CYL. L.O. Compressed air
Generator engine (D/G, T/G) Compressed air
L.O transfer L.O purifier L.O Stern Tube
Compressed air
L.O. filling Compressed air
Compressed air Main engine starting air, auxiliary diesel engine starting air & control air
Compressed air
Hydraulic oil piping
Deck machinery Flushing oil
V.R.C. (main line) system Flushing oil
V.R.C. (multi line) system Nitrogen
Steam piping Steam supply line for steam driven machinery Steam
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2. PRE-OUTFITTING PROCESS
2.1. Outfitting work during Block Assembly
Outfitting works as pipes, supports, ducts, electric cable trays, machinery seats, hand grip and steps, etc. are to be fitted throughout hull blocks assembling works or block assy site as far as practical.
2.2. Outfitting work during Block Erection
In general, the installation of machinery, electrical equipment, outfitting, etc. is to be carried out in parallel with the hull construction works at pre-erection stage and/or dock stage.
2.3. Unit Assembly
(1) Auxiliary machinery having similar function or closed location are to be assembled into appropriate units together with their seats or beds, piping and steel outfitting, electrical equipment, etc. in the shop or sub-supplier shop.
(2) Each unit is to be installed at block stage or pre-erection stage. After installing the units, the shaft centering of the auxiliary machinery is to be checked and corrected by use of shim plate, if required.
2.4. Outfitting of Superstructure
(1) Outfitting such as mast, posts, piping, ducting, paneling, ceiling, flooring, cabling, etc. are to be done at the assembling stage as far as practical.
(2) In connection with the outfitting works, hydraulic or water flooding test of piping may be carried out individually at each block and then connection joint parts are to be checked onboard after the whole installation has been completed.
2.5. Galvanizing of Fittings
Galvanized surfaces must be practically smooth and free from conspicuous defects such as bare spots.
Note: Damaged parts caused by gas cutting or welding are to be generally touched up by zinc rich solution paint.
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3. MACHINERY OUTFITTING PROCESS
3.1. Shafting and Propeller
3.1.1. Pre-sighting and Stern Tube Boring
(1) Condition of pre-sighting
a) Pre-sighting is to be carried out after stern boss block is assembled and welded to engine room tank top block (see Fig.1).
b) Pre-sighting is to be carried out at pre-erection area or in the dock.
Fig.1. Pre-sighting condition
(2) Procedure of pre-sighting and stern tube boring
After above-mentioned condition is completed, pre-sighting is to be carried out:
CASE 1 Check with light box a) Fix the center line level between stern boss and main engine (see
Fig.2-1).
Fig. 2-1 Pre-sighting (Case 1)
CASE 2 Check with laser measuring equipment (Total station) a) The centering gauge is to be installed at the inside of Aft Stern
Tube (see Fig.2-2). b) Laser measuring equipment (Total Station) is to be installed in
line with center of shaft
Stern boss block
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Fig. 2-2 Pre-sighting (Case 2) c) Measure and mark down the distance of shaft length and the
dimension of engine bed plate according to the Shafting Plan (drawing)
d) Bore the Aft & Fore stern boss e) Before facing stern boss, final boring center is to be confirmed
with reference marks on both stern faces prepared before boring, and the stern tube bearing are to be fitted into boss with proper fitting force.
3.1.2. Rudder Horn Boring at Pre-erection Stage
CASE 1 (1) Application condition
This case is to be applied when rudder horn block is assembled to Steering Gear deck block to make a super block at pre-erection stage.
Boring can be started after completion of welding of shell plates and all internal strength members.
(2) Procedure a) After above-mentioned condition is completed, sighting is to be
prepared.
b) Install the piano wire perpendicularly from Steering Gear deck through center of rudder horn bosses and measure eccentricities of upper and lower bosses.
c) Mark down reference circle for machining and bore the rudder horn bosses.
d) Fit the bushes by chilling with dry ice or liquid nitrogen, after machining according to the inside diameter of the bosses.
F
F: TOTAL STATION A & B: CENTERING GAUGE
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M/Deck
S/G Deck
B
C
A
Fig. 3. Rudder horn boring
CASE 2 (1) Application condition
This case is to be applied when rudder horn casting is assembled and welded to rudder horn super block.
(2) Procedure a. After above-mentioned condition is completed, sighting is to be prepared. b. Provide boring machine seat on the top of rudder horn. c. Install the piano wire perpendicularly from the boring seat through
center of rudder horn bosses. d. Measure and record the degree of perpendicularly of rudder horn
and eccentricities of lower and upper bosses. e. Bore rudder horn bosses and measure the inside diameter of the bosses.
Fig. 4 Rudder horn boring
After rudder horn block is erected and welded to Steering Gear deck block, final sighting is to be carried out to measure the degree of perpendicularity of the rudder horn and eccentricity of the bosses from actual perpendicular line.
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Bushes are to be machined in accordance with the eccentricity of the rudder horn bosses and fitted to bosses by chilling with dry ice or liquid nitrogen.
CASE 3 (1) Application condition
This case is to be applied when rudder horn boring is carried out at shop before block assembly.
(2) Procedure a. After rudder horn block is erected and welded to steering gear deck
block completely, final sighting is carried out at dock stage.
b. Install the piano wire.
c. Measure the dimension and eccentricity of rudder horn gudgeon.
d. Bushes are to be machined in accordance with the eccentricity of the rudder horn gudgeon.
e. Fit the bushes by chilling with dry ice or liquid nitrogen.
3.1.3. Fitting of Stern Bush
CASE 1 Press fitting (1) The installation of stern bush is to be carried out by using hydraulic
oil jack as below figure.
Stern frame
Fore stern bush After stern bush
Oil jack
a b
(2) Pressure and load of the hydraulic power are to be measured against inserting distance of the bush.
(3) The measurement is to be recorded at the last 100 mm (b) drive for forward bush and at the last 250 mm (a) drive for the aft-bush.
(4) Insertion load is to be applied as following figures:
Insertion load is decided according to the design calculation of shafting plan
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Note: This insertion load is just as an aim; reference is to be made to the calculation for the particular ship.
CASE 2 Freeze fitting In case of resin bush, the installation of stern bush is to be carried out by maker recommendation.
CASE 3 Epoxy resin fitting The installation of stern bushes is to be carried out by pouring epoxy resin. Before pouring the epoxy resin, the centering of stern bushes shall be confirmed.
3.1.4. Installation of Shaft
(1) The propeller shaft with propeller can be installed at pre-erection stage or in dock
(2) The main engine and the intermediate shaft bearings are to be temporally installed and then the shaft is to be fixed with the off-set value decided in the design stage.
(3) After adjusting the off-set, the shaft is to be connected with the coupling bolts.
(4) The coupling reamer bolts are to be fitted by chilling with dry ice, liquid hydrogen or other methods such as hammering and using the hydraulic jack (insertion load: 3-20 tons)
(5) After tightening the coupling bolts, each shaft bearing may be jacked up according to the drawing to check whether the load is within the allowable limits.
3.1.5. Contact Conditions of Propeller Shaft and Propeller
(1) The contact surface condition is to be checked by contacting the propeller's boss and shaft with coating the blue or red paint on cone-part of the shaft.
(2) When the keyed propeller is provided, after fixing the key to propeller shaft, the contact condition of the cone-part is to be checked.
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(3) The acceptable contact ratio is at least 70% of the matching area.
3.1.6. Fitting of Propeller
The push-up distance of propeller is obtained from the computation table to which the measured temperatures are applied.
3.1.7. Tightening-up of Propeller Nut
The propeller nut is to be tightened up to following final torque.
2
200 400 600 800 1000
468
101214
Nut tightening torque of Keyed propeller
Propeller shaft dia. [mm]
Nut
tigh
teni
ng to
rque
[Tm
] ( 1
Tm
= 9
.8 k
Nm
)
3.1.8. Final Sighting
(1) Condition of final sighting Final sighting is to be carried out when the rudder horn block (A.P tank), E/R block and steering gear deck are assembled together and all strength members of hull structure are welded (see Fig.5).
M/DeckS/G Deck
Fig. 5. Condition of final sighting
(2) Procedure of final sighting
a) When the above-mentioned condition is completed, final sighting is to be carried out.
b) Install the piano wire at the shaft centerline from center of tail shaft (propeller cap) to aft (see Fig.6).
c) Install the piano wire from center of rudder horn perpendicularly to the ground, and then measure the deviation from the shaft centerline (see Fig.6).
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d) Measure the dimension of rudder horn and the height up to steering gear deck.
e) Bore rudder horn bosses and measure inside diameter of the machined holes. (In some cases, boring and measuring the rudder horn bosses are to be finished at pre-erection stage).
f) Measure the dimensions of machined neck, pintle bush and rudder horn bosses at same temperature condition, and fit the pintle bushes by chilling with dry ice or liquid nitrogen.
Fig. 6. Final sighting
3.1.9. Tightness Test of Oil Seal
(1) After installation of the seals at the fore and aft part of the stern bearing, the oil is to be filled in the stern tube and the head tank up to the level corresponding to the ship's full loaded condition. Then the oil level is to be maintained at least 4 hours.
(2) The tightness of the oil seals is to be checked after detaching the bottom plugs of the seal.
3.1.10. Mounting of Shaft Coupling
(1) The centering of both the propeller shaft and intermediate shaft are to be checked.
(2) After centering the both ends, the SAG & GAP at four places - of top, bottom, port and starboard - between the propeller shaft and intermediate shaft are to be measured. The values have to be according shafting plan.
3.2. Main Diesel Engine & Appurtenant Equipment 3.2.1. Installation of M/E foundation
(1) Mark down the position of engine foundation after pre-sighting. (2) Cut the hole for engine foundation. (3) Fit up and weld the side stoppers. (4) Clean engine foundation an
Recommended