Doc. No:
111116-N-PA-006
Doc. Title:
Sheets:
THERMAL FAIRING PROCEDURE
Project :
TRANSOCEAN-DRILL SHIP #1 & #2
Job No:
11-1116 / 11-1117
Unit :
DRILL SHIP
Client :
TRANSOCEAN
1 of 6
REVISION INDEX
Revision
DESCRIPTION AND / OR REVISED SHEETS
A
Issued for TRANSOCEAN & DNV Approval
0
Issued for TRANSOCEAN & DNV Approval
1
Issued for TRANSOCEAN & DNV Approval
By Steven Snyder at 11:17 am, Apr 09, 2018
REVISION
Rev. A
Rev. 0
Rev. 1
DATE
23/12/2014
09/02/2015
06/04/2018
PREPARED
VARUN
VARUN
VASEEHARAN J
CHECKED
P ARUNKUMAR
P ARUNKUMAR
SENTHIL KUMAR
APPROVED
B K CHOO
B K CHOO
P ARUNKUMAR
THE DATA ( OR ) PARTS THEREOF, ARE JSPL PROPERTY AND THUS SHALL NOT BE USED IN ANY FORM WITHOUT PERMISSION
Project:
TRANSOCEAN-DRILL SHIP
DOC TITLE:
Sheet:
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THERMAL FAIRING PROCEDURE
CONTENTS
S.No
TITLE
PAGE
1.0
Objective
3
2.0
Scope
3
3.0
Responsibility
3
4.0
Procedure
5.0
Applicable Codes, Standards and Specifications
6
Appendix I
6
Doc. No. 111116-N-PA-006
Rev. 1
3~5
Project:
Sheet:
TRANSOCEAN-DRILL SHIP
DOC TITLE:
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THERMAL FAIRING PROCEDURE
1.0
OBJECTIVE
1.1
2.0
This procedure is developed to straighten the structural members.
SCOPE
2.1
This Instruction shall be applicable for fairing of distorted structural members for
which are found unacceptable under Specific codes and/or Specifications.
3.0
RESPONSIBILITY
3.1
The engineer in charge shall be responsible to arrange the necessary manpower tool,
material and lifting equipments in order to carry out the job.
3.2
Section respective personnel & QA/QC Inspector shall monitor in process thermal
fairing activity and check visually after the fairing.
3.3
The personnel who performs thermal fairing job shall be experienced and skillful as
well as undergone documented training of thermal fairing.
3.4
It is responsibility of personnel in SF to supervise and minimize distortion in welding
fabrication to avoid thermal fairing by documented training.
1
4.0
PROCEDURE
4.1
Distorted members shall be straightened either by mechanical means or by heating
with a fairing torch or combination of both methods. Mechanical straightening shall be
carried out by pressing, jacking.
4.2
During fairing the distance between nozzle tip and material surface shall be
maintained between 16 mm to 22 mm. (Refer below figure.)
Doc. No. 111116-N-PA-006
Rev. 1
Project:
TRANSOCEAN-DRILL SHIP
DOC TITLE:
Sheet:
4 of 6
THERMAL FAIRING PROCEDURE
1
4.3
During fairing the distance between the fairing torch nozzle tip to water nozzle shall
be maintained minimum 50 mm. (Refer below figure & table.)
1
Doc. No. 111116-N-PA-006
Rev. 1
Project:
TRANSOCEAN-DRILL SHIP
DOC TITLE:
Sheet:
5 of 6
THERMAL FAIRING PROCEDURE
4.4
Maximum heating temperature for straightening distorted members shall refer to
Appendix I.
4.5
The temperature of the heated areas shall be measured using Temperature Stick with
1
the three different temperatures (650̊ C. 593̊ C and 550̊ C).
4.6
Where necessary jigs and clamps shall also be used to straighten the distorted
members.
4.7
Finally all heated members shall be cooled in accordance to Appendix I.
4.8
Yard shall notify the Owners and Class whenever/wherever members distorted by
welding are to undergo straightening by mechanical means and/or limited amount of
localized heating. Corrective measures relating to flame straightening shall always be
conducted with due regard to possible degradation of the material properties.
4.9
Heating directly on the weld to be avoided as much as possible. If heating on the weld
is not avoidable temperature must not exceed the levels. After heating weld to be
100% NDT (UT/MPI) hardness to be performed.
4.10
1
NDT is required on any area / weld / HAZ after heating or mechanical straight
pressing or jacking. Hardness test need to perform if requested by TOI / DNV GL.
4.11
The gas that will be used for heating shall be LPG or Acetylene.
Note:
a) Item 4.5, temperature stick covering the maximum heating temperature should be used.
b) Fairing by heating is not completely effective for steel with yield deformation; hence crop
and renewal may be necessary in some instance.
c) For indents affecting internal structure, plating may in some cases be released from the
internals and pushed back in place. Internals shall then be renewed or repaired as found
necessary with approval of owner and Class.
d)
When heat straightening or heat curving methods are used, the maximum temperature of
heated areas are measured continuously using temperature sensitive crayons or digital
thermometer, with temperature shall not exceed 1100°F [600°C] for quenched and
tempered steel, nor 1200°F [650°C] for other steels.
e)
Thermal fairing is not allowed on steel plates above 460 grades without case by case
approval from Owner and Class.
f)
Reference to diagonal, multi-frame and spot heating methods may be made for thermal
fairing, as required.
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Rev. 1
1
Project:
TRANSOCEAN-DRILL SHIP
DOC TITLE:
Sheet:
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THERMAL FAIRING PROCEDURE
5.0
APPLICABLE CODES, STANDARDS AND SPECIFICATIONS
5.1 IACS (No.47, Shipbuilding and repair quality standard) Part A Sec 6.
5.2 Offshore Standard DNV-OS-C401 (2012). Chapter 2, sec.2, page 45~49
5.3 DNV Rules for Ships Part2 Chapter 3 F300 or DNV OS C401 Ch.2 Sec.2/6.4 Page 54
APPENDIX - I
Maximum Heating Temperature on Surface for Line Heating
Doc. No. 111116-N-PA-006
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