Post Weld Heat Treatment Procedure

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TABULATION OF REVISED PAGES

PAGE Rev.1 Rev.2 Rev.3 Rev.4 Rev.5 1 X 2 X 3 X 4 X 5 X 6 X 7 X 8 X 9 X

10 X 11 X 12 X 13 X 14 X 15 X 16 X 17 X 18 X 19 X 20 X

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TABLE OF CONTENTS

1. PURPOSE

2. DEFINITION

3. REFERENCE

4. GENERAL

5. PRE-HEATING

6. POST-WELD HEAT TREATMENT

7. HARDNESS TEST

8. DOCUMENT

9. ATTACHMENT

SOUTH PARS GAS FIELD DEVELOPMENT (PHASES 15&16)

POST WELD HEAT TREATMENT

PROCEDURE

Doc. No. : I.I.R-15-0-PR-0001 Rev. No. : 1 Class : 1

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1 PURPOSE

This procedure covers the preheating, post heating, post-weld heat-treatment and hardness testing of piping component for South Pas 15 & 16 Project.

2 DEFINITIONS

COMPANY : NATIONAL IRANIAN OIL COMPANY(NIOC) / Pars Oil and Gas Company(POGC) or his nominated representative

CONTRACTOR : The party (IIRCo/Sievert CONSORTIUM) which entered under Contract

Agreement with COMPANY for the NDT a nd PWHT Facilities regarding the South Pars Field Development Project 15&16.

SUBCONTRACTOR : shall mean any company, firm or person with whom CONTRACTOR enters

into a subcontract.

THIRD PARTY : any inspection service person or company who is independent from COMPANY, CONTRACTOR AND SUBCONTRACTOR.

“SITE” means the location for installation of the facilities at ASSALUYEH or the vicinity thereof in the

IRAN

3 REFERENCE

Unless otherwise stated, the latest edition or revision of following codes of practice, specifications and standards at the time of order placement apply.

ASME B31.3 Process piping ASME B31.8 Gas Transmission System for Liquid Hydrocarbon and Other Liquids API 1104 Welding of Pipeline and Related Facilities

4 GENERAL

4.1 CONTRACTOR is responsible for the preparation, implementation and control of PWHT works. 4.2 The CONTRACTOR's PWHT QC Engineer is responsible for the inspection of PWHT works

and review of the PWHT records 4.3 In addition to this procedure and related codes, standards, and specifications WPS's shall be applied

to Preheating and PWHT and Hardness testing. In case of conflict between this procedure and WPS, WPS requirements will be followed

4.4 PWHT shall be performed with local furnace or local heating method by use of electric resistance heaters.

4.5 Following equipments and materials to be used for heating.

1) 50KVA heat-treatment system

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2) 100KVA 3-WAY 3-PHASE heat treatment system 3) 200KVA 6-WAY 3-PHASE heat treatment system 4) Multi-point temperature recorder 5) Capacitor discharge type Thermo-Couple attachment unit 6) K-type milli-volt source unit 7) Mat type heaters with 60V x 45A x 2.7KW and other specifications 8) 14/22/38mm2 feeding heating cable set w/camlok connectors 9) 3-WAY splitter cable set w/camlok connectors 10) K-type consumable Thermo-Couple wire 11) VX-type Thermo-Couple compensating cable 12) 110V auxiliary cable set

4.6 Temperature measuring shall be accomplished through the measuring system consists of K-type consumable wire Thermo-Couple, VX-type compensating cable and Temperature recorder.

4.7 Calibration status of measuring materials and equipments to verify PWHT temperature shall be controlled as followings ;

4.7.1 K-type milli-volt source units and temperature recorders shall have been calibrated prior to use, and shall be calibrated at least every 12 months.

4.7.2 K-type consumable wire Thermo-Couple shall have been certified for its accuracy

by production lot before use.

4.7.3 Calibration and certification of instrumentation shall be performed by authorized agency approved by government.

4.7.4 Each 1 copy of calibration certificates issued by authorized calibration agency shall be submitted to CONTRACTOR.

5 PREHEATING

5.1 General Preheating is used, along with heat treatment, to minimize the detrimental effects of high temperature and severe thermal gradients inherent in welding, thermal cutting and arc-air gouging. The necessity for preheating and the temperature to be used shall be specified in the engineering design and demonstrated by procedure qualification. The requirements and recommendations herein apply to all types of welding including tack welds, repair welds, and seal welds of threaded joints.

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5.2 Requirements and preheating/inter-pass temperature

5.2.1 Required minimum preheat temperatures for materials of various P-No.'s are given in Table

5-1. But, all ferritic materials shall be preheated at least 80℃ regardless of thickness and

tensile strength, if the weld is under a high degree of restraint; e.g branch connections.

The thickness intended in Table 5-1 is that of the thicker component measured at the joint. For

ferritic material, when the required preheat temperature is 200℃ or higher, and for thickness

greater than 50mm, the metal shall be maintained at preheat temperature until the weld is post weld heat treated. Alternatively, the weld shall be given a hydrogen diffusion treatment

before allowing any cooling. This treatment shall consist of heating to 250℃ minimum,

holding for four hours, then slowly cooling under thick dry insulation blankets to ambient temperature. For lower preheat temperatures, the joint shall have been completed and the cooling rate minimized by wrapping the joint in dry insulating blankets. Should the welding be interrupted, the required minimum preheat temperature shall be re- established over the entire joint length to be welded before welding resumes.

5.2.2 The maximum inter-pass temperature for austenitic stainless steels (P-8) shall be 150℃.The maximum inter-pass temperature for carbon steels (P-1) shall be 250℃, unless prior

approval is given by COMPANY.

5.2.3 Dissimilar Materials

When materials having different preheat requirements are welded together, it is recommended that the higher temp. shown in Table 5-1 be used.

5.2.4 Unlisted Materials Preheat requirements for an unlisted material shall be specified in the WPS.

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TABLE 5-1. PREHEAT TEMPERATURES (Table 330.1.1 in ASME B31.3)

Base Metal P-NO.

[Note1]

Weld Metal

Analysis A-NO. [Note2]

Base Metal Group

Nominal Wall

Thickness

Specified Min. Tensile

Strength, Base Metal

Min. Temp.

Required Recommended

MM INCH MPa ksi ℃ ℉ ℃ ℉

1

1

Carbon steel* < 25.4 < 1 ≤ 490 ≤ 71 ... ... 10 50 ≥ 25.4 ≥ 1 ALL ALL 100 212 79 175 ALL ALL > 490 > 71 100 212 79 175

3

2,11

Alloy steels, Cr ≤ ½%

< 12.7 < ½ ≤ 490 ≤ 71 ... ... 10 50 ≥ 12.7 ≥ ½ ALL ALL ... ... 79 175 ALL ALL > 490 > 71 ... ... 79 175

4 3 Alloy steels, ½%<Cr≤ 2%

ALL

ALL

ALL

ALL

149

300

...

...

5 4,5 Alloy steels, 2¼%≤ Cr≤

ALL

ALL

ALL

ALL

200

392

...

...

6 6 High alloy steels, martensitic

ALL

ALL

ALL

ALL

...

...

149

300 7 7 High alloy steels,

ferritic

ALL

ALL

ALL

ALL

...

...

10

50 8 8,9 High alloy steels,

austenitic

ALL

ALL

ALL

ALL

...

...

10

50 9A,9B** 10 Ni-alloy steels ALL ALL ALL ALL 150 302

10 ... Cr-Cu steel

ALL

ALL

ALL

ALL 149- 204

300- 400

...

... 10A ... Mn-V steel ALL ALL ALL ALL ... ... 79 175 10E ... 27Cr steel ALL ALL ALL ALL 149 300 ... ...

11A SG1 ... 8Ni,9Ni steel ALL ALL ALL ALL ... ... 10 50 11A SG2 ... 5Ni steel ALL ALL ALL ALL 10 50 ... ...

21-52 ... ... ALL ALL ALL ALL ... ... 10 50 [Notes] (1) P-Number from BPV Code, ASME SECT. IX, Table QW-422. Special P-Numbers(SP-1, SP-2, SP-3, SP-4 ,and SP-

5), require special consideration. The required thermal treatment for Special P-No.'s shall be established by the engineering design and demonstrated by the WPQ.

(2) A-Number from BPV Code, ASME SECT.IX, QW-442. (3) Max. interpass temperature 600℉ (316℃)

(4) Maintain interpass temp. between 350℉ -450℉ (177℃-232℃). * For CE % ≥ 0.42, preheat not less than 100℃

** For P No. 9B, Preheat at 95℃ is only acceptable for thickness up to 10mm

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5.3 Heated zone and insulation

5.3.1 Preheat shall be uniform and shall include a zone which is not less than 2t(t=wall thickness), with a minimum of 75mm, either side of the joint.

5.3.2 Electric heating elements shall be covered with a minimum of 50mm ( 25mm for up to 2") thickness of insulation, extending minimum 75mm either side of heated zone. Insulation

shall be ceramic fiber, and the ceramic fiber shall be of 1000℃ continuous service

temperature and of 100 kg/m3 bulk density, and suitable for the heating temperature.

5.4 Interrupted welding and post-heating

5.4.1 Weld shall be applied to the whole length and completed as far as practicable without interruption. Where production conditions are that welds have to be left partially completed, the following conditions shall apply. - Welding shall not be discontinued until at least 1/3 of the joint thickness is completed. - Upon discontinuation of welding the joint shall be wrapped in dry insulating material and

should be cooled in a slow and uniform manner. - Prior to recommencement of welding, the joint shall be examined using the magnetic

particle inspection technique and reheated to within the specified inter-pass heat range. 5.4.2 Application of preheating when using gas burners shall avoid deposition of carbon.

5.5 Temperature Verification

5.5.1 Preheat temperature shall be checked by use of temperature-indicating crayons, calibrated thermocouple pyrometers, or other approved suitable means to ensure that the temperature specified in the WPS is obtained prior to and maintained during welding. Temperature- indicating materials and techniques shall not be detrimental to the base metals. Whatever method to be used shall be specified in WPS

5.5.2 The preheat temperature shall be measured on the face opposite to that being heated when possible. When this is not possible, allowance shall be made for temperature equalization, e.g. remove heat source and allow period of one minute for each 25mm thickness of material to elapse, before measuring temperature.

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6 POST-WELD HEAT-TREATMENT

6.1 General Heat treatment is used to avert or relieve the detrimental effects of high temperature and severe and sharp

temperature gradients inherent in welding, and to relieve residual stresses created by bending and forming.

Exposed machined and threaded surface shall be protected from oxidation during heat treatment.

6.2 Heat-treatment requirements

6.2.1 Heat-treatment shall be in accordance with RP-6340S-999-6300-001 and the material groupings and

thickness ranges in Table 6-1, Table 6-2 & 6.3 and also material grouping governed by ASME B31.8

except as provided in paragraph 6.2.2 and 6.4.

No PWHT shall be performed on Austenitic stainless steel.

6.2.2 Special requirements

Carbon steels in Sour service All pipe work must be subject to a post weld heat treatment, irrespective of their thickness, except for socket welds on sizes less then 2 inches in diameter. The post weld heat treatment must be performed in accordance with the requirements of the design code even though the thickness of the material may be below the minimum value requiring such a heat treatment. The soaking time must be a minimum of one hour ; the heat treatment temperature shall be a minimum of 620 + 20oC/-0 oC The requirements described in this paragraph shall have priority than any other requirements. In

addition to the requirements of ASME B31.3, PWHT shall be applied to welds in ferritic materials in

the following services.

(1) Amine service (2) Caustic service, when so advised

6.3 Governing thickness

When components are joined by welding, the thickness to be used in applying the heat- treatment provisions of Table 6-1 and Table 6-2 shall be that of the thicker component measured at the joint except as follows.

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TABLE 6-1. POST-WELD HEAT-TREATMENT

Material

P No.

Thickness (mm) Holding Temp. (℃) Time at holding Temperature

Minutes/mm Minimum minutes Carbon and Carbon

Manganese steel

1

> 19 (Note 2)

600 - 620 2½

60

1¼Cr-½Mo 4 All 650 - 710 2½ 120

2¼Cr-1Mo 5 All 720 - 745 2½ 120

5Cr-½Mo 5 All 720 - 745 2½ 120

7Cr-½Mo 5 All 720 - 745 2½ 120 9Cr-1Mo 5 All 720 - 745 2½ 120

Note 1. PWHT of dissimilar materials shall be considered in relation to the service conditions and the procedure shall

be subjected to COMPANY’s acceptance.

2. When PWHT is specified for particular duties (See para. 6.2.2) PWHT shall be performed on welds of all thickness.

(a) In the case of branch connections, metal (other than weld metal) added as reinforcement, whether an integral part of a branch fitting or attached as a reinforcing pad or saddle, shall not be considered in determining heat treatment requirements. Heat treatment is required, however, when the thickness through the weld in any plane through the branch is greater than twice the minimum material thickness requiring heat treatment, even though the thickness of the components at the joint is less than the minimum thickness. Thickness through the weld for the details shown in FIG.328.5.4D OF ASME B31.3 shall be computed using the following formulas: Detail(a)

·weld thickness = tnb ＋ tc

Detail(b)

·weld thickness = tnh ＋ tc

Detail(c)

·weld thickness = greater of [tnr ＋ tc] or [tnb ＋ tc]

Detail(d)

·weld thickness = tnh ＋ tnr ＋ tc

Detail(e)

·weld thickness = tnb ＋ tc

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(b) In the case of fillet welds at slip-on and socket welding flanges and piping connections NPS 2 and smaller, for seal welding of threaded joints in piping NPS 2 and smaller, and for attachment of external non-pressure parts such as lugs or other pipe supporting elements in all pipe sizes, heat treatment is required when the thickness through the weld in any plane is more than twice the min. material thickness requiring heat- treatment (even though the thickness of the components at the joint is less than that min. thickness) except as follows:

(1) not required for P-No.1 materials when weld throat thickness is ⅝ " (16 mm) or less

regardless of base metal thickness;

(2) not required for P-No. 3, 4, 5, or 10A materials when weld throat thickness is ½"(13mm)

or less, regardless of base metal thickness, provided that not less than the recommended preheat is applied, and the specified min. tensile strength of the base metal is less than 71 ksi (490 MPa);

[REF. NOTE] 1 ksi = 1000 psi = 1000 x 0.07036 kgf/Cm2

= 70.36 kgf/Cm2 = 70.36 x 9.8 x 104 N/m2[Pa] = 6,895,280 N/m2[Pa] = 6.895280 MPa

(2) not required for ferritic materials when welds are made with filler metal which does not air harden. Austenitic welding materials may be used for welds to ferritic materials when the effects of service conditions, such as differential thermal expansion due to elevated temp., or corrosion, will not adversely affect the weldment.

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7 7

8 8, 9

TABLE 6-2. REQUIREMENTS FOR HEAT-TREATMENT (Table 331.1.1 in ASME B31.3)

BASE

METAL

WELD

METAL

BASE METAL

NOMINAL WALL

THICKNESS

SPECIFIED MIN.

TENSILE STRENGTH METAL TEMP. RANGE HOLDING TIME

BRINELL

HARDNES

P-NO. [NOTE](1)

ANALYSIS A-NO.

[NOTE](2)

GROUP

MM INCH MPa ksi ℃ ℉ HR/INCH

NOMINAL WALL

MIN. TIME (HR)

S [NOTE] (4) MAX.

1 1 CARBON STEEL

ALLOY

STEEL

≤ 19 ≤ ¾ ALL ALL None None ... ... ... > 19 > ¾ ALL ALL 600-620 1112-1148 1 1 ... ≤ 19 ≤ ¾ ≤ 490 ≤ 71 None None ... ... ...

3 2, 11

4 3

Cr≤ ½%

ALLOY STEEL ½%<Cr≤ 2%

ALLOY STEEL

> 19 > ¾ ALL ALL 593-718 1100-1325 1 1 225 ALL ALL >490 > 71 593-718 1100-1325 1 1 225 ≤ 12 7 ≤ ½ ≤ 490 ≤ 71 None None ... ... ... > 12.7 > ½ ALL ALL 704-746 1300-1375 1 2 225 ALL ALL > 490 > 71 704-746 1300-1375 1 2 225

5A, 5B, 5C

4, 5 (2¼%≤ Cr≤ 10%) ACCORDING TO FOLLOWING DETAIL DIVISION(TRANSLATION NOTE)

(≤ 3%Cr and ≤ 0 15%C) ≤ 12 7 ≤ ½ ALL ALL None None ... ... ... (>3%Cr or >0.15%C or) > 12.7 > ½ ALL ALL 720-750 1328-1382 1 2 241

MARTENSITIC HIGH 6 6 ALLOY STEELE ALL ALL ALL ALL 732-788 1350-1450 1 2 241

A240 Gr.429 ALL ALL ALL ALL 621-663 1150-1225 1 2 241 FERRITIC HIGH ALLOY STEELE ALL ALL ALL ALL None None ... ... ...

AUSTENITIC HIGH ALLOY STEELE ALL ALL ALL ALL None None ... ... ...

9A, 9B 10 ...

Ni- ALLOY STEEL ≤ 19 ≤ ¾ ALL ALL None None ... ... ... > 19 ≤ ¾ ALL ALL 593-635 1100-1175 ½ 1 ...

10 ... Cr- Cu STEEL ALL ALL ALL ALL 760-8165 1400-15005 ½ ½ ...

≤ 19 ≤ ¾ ≤ 490 ≤ 71 None None ... ... ... 10A ... Mn-V STEEL > 19 > ¾ ALL ALL 593-704 1100-1300 1 1 225

ALL ALL > 490 > 71 593-704 1100-1300 1 1 225 10E ... 27Cr STEEL ALL ALL ALL ALL 663-7046 1225-13006 1 1 ... 10H ... Cr-Ni-Mo STEEL ALL ALL ALL ALL [Note] (7) [Note](7) ½ ½ ...

11A SG1 ... 8Ni, 9Ni STEEL ≤ 51 ≤ 2 ALL ALL None None ... ... ... > 51 > 2 ALL ALL 552-5858 1025-10858 1 1 ...

11A SG2 ... 5Ni STEEL > 51 > 2 ALL ALL 552-5858 1025-10858 1 1 ... 62 ... Zr R60705 ALL ALL ALL ALL 538-5939 1000-11009 [Note](9) 1 ...

[NOTE] (1) P-Number from BPV Code, ASME Section lX, Table QW-422. (2) A-Number from BPV Code, ASME Section lX, Table QW-442. (3) For SI equivalent, hr/mm, divide hr/in. by 25. (4) See para.5.2.5. (5) Cool as rapidly as possible after the hold period. (6) Cooling rate to 1200℉ (649℃) shall be less then 100℉ (56℃)/hr; thereafter, the cooling rate shall be fast enough to prevent embrittlement.

(7) Post-weld heat-treatment is neither required nor prohibited, but any heat-treatment applied shall be performed at 1800℉ -1900℉ (982℃-1038℃) followed by rapid cooling.

(8) Cooling rate shall be >300℉ (167℃)/hr to 600℉ (316℃). (9) Heat treat within 14 days after welding.

Hold time shall be increased by ½ hr for each inch over 1" thickness.

Cool to 800℉ (427℃) at a rate ≤ 500℉ (278℃)/hr, per 25mm(1in.) nominal thickness,

500℉ (278℃)/hr max. Cool in still air from 800℉ (427℃).

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TABLE 6-3. POST-WELD HEAT-TREATMENT(Pipelines to API 1104)

Material

Thickness (mm) Holding Temp. (℃) Time at holding Temperature

Minutes/mm Minimum minutes

Carbon steel

> 31.75

590 ~ 610 (Note 1) 2½

60 Note 1.According to the agreement with Company, Holding temperature could be changed.

2. Any sections, if the relevant welding procedure qualification exhibits hardness exceeding 248HV5.

3. Only electrical methods shall be used for heating

4. If either material in welds between dissimilar material required stress relieving, the joint shall require stress relieving.

5. All welding of connections and attachments shall be stress relieved when the pipe is required to be stress relieved by

the rule of project specification with the following exceptions.

5-1) Fillet & groove welds not over 12.7mm size(leg) that attach connections not over NPS 2 pipe size

5-2) Fillet & groove weld not over 9.5mm groove size, which attach support members or other non-

pressure attachments.

6. The parts heated shall be brought slowly to the required temperature and held at that temperature for a period of

time proportioned on the basis of at least 1 hour/25.4mm of pipe wall thickness, but in no case less then 1 hour and

shall be allowed to cool slowly and uniformly.

7. When stress relieving a joint between dissimilar materials having different stress relieving requirements, the material

requiring the higher PWHT temperature shall be govern.

8. Branched or other welded attachments for which PWHT is required may be locally stress relieved by heating

circumferential band around the pipe on which the branch or attachments is welded with attachment at the middle

of the band the width of band shall be at least 50mm greater than the diameter of weld joint the branch or

attachment to header.

6.4 Alternative heat-Treatment Normalizing, or normalizing and tempering, or annealing may be applied in lieu with the required heat treatment after welding, bending, or forming, provided that the mechanical properties of any affected weld and base metal meet specification requirements after such treatment and that the substitution is approved by the designer.

6.5 Dissimilar materials

6.5.1 Heat treatment of welded joints between dissimilar ferritic metals or between ferritic metals using dissimilar ferritic filler metal shall be at the higher of the temp. ranges in Table 6.1 and Table 6.2 for the materials in the joint.

6.5.2 Heat treatment of welded joints including both ferritic and austenitic components and filler

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metals shall be as required for the ferritic material or materials unless otherwise specified in the engineering design.

6.5.3 Austenitic stainless steel to dissimilar material shall be complied with qualified WPS which is approved by COMPANY/TPA.

6.6 Delayed PWHT

Where PWHT of Cr-Mo steel is required, the weld shall be immediately heat-treated without

allowing it to cool below 150℃. If this is not practical, the weld shall be uniformly heated to

325℃, wrapped with insulation, allowed to cool, and heat-treated later.

6.7 deleted

6.8 Heating and Cooling

6.8.1 The maximum heating rate above 300℃ shall not exceed 220℃/HR or 5500/t ℃/HR (where t = wall thickness in mm), whichever is lower. (not exceed 220℃/HR in any case).

6.8.2 The maximum cooling rate above 300℃ shall not exceed 275℃/HR or 6875/t ℃/HR (where t = wall thickness in mm), whichever is lower. (not exceed 275℃/HR in any case). Cooling under 315℃ can be accomplished with removal of insulation and left it in air. Cooling and heating rate is not under 55℃/HR .

6.9 Temperature verification

6.9.1 During PWHT, temperatures shall be carefully checked and recorded by use of Thermo- Couple's to and accessories ensure that the PWHT is applied in compliance with the PWHT specification.

6.9.2 The Thermo-Couple wires shall be Ni-Cr / Ni-Al (TYPE 'K'), and welded directly onto the outer surface of the weld metal by using a capacitor discharge type Thermo-Couple welding unit, and the hot junction of Thermo-Couple (attached point) shall be heat-insulated with thermocouple putty.

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6.9.3 When welding a Thermo-Couple, the distance between the 2 poles shall be within 6mm and

the attaching depth of Thermo-Couple shall not be over 0.2-0.5mm.

6.9.4 The Compensating wire between Thermo-Couple wires and temperature recorders shall be of the Cu-constantan (VX) type. The Cu lead(+Ve) shall be connected to Ni-Cr conductor(non- magnetic) and the constantan lead (-Ve) to the Ni-Al conductor (magnetic).

6.9.5 The Thermo-Couple's shall be connected to continuously monitoring temperature recorders.

These recorders shall be of the range 0 - 1200℃, and be set at a chart speed of 25-50mm/HR,

and provide a total record of temperature during heating, holding and cooling period above

the loading temperature of 300℃.

6.9.6 If several welds are heat-treated simultaneously, the temperatures of each weld shall be recorded with individual identification.

6.9.7 Thermocouple requirement

(1) The number and position of the Thermo-Couple's shall be in accordance with Table 6.3 (2) The thermocouples shall be mechanically attached to the parts being heat treated, and

within 40mm from the outside surface of the weld metal (3) For weld on horizontal pipe, one of required Thermo-Couple's shall be placed on top of

pipe. For welds on vertical pipe at least one thermocouple shall be placed adjacent to the weld on top and the other one places adjacent to the weld on bottom.

(4) After removal of the Thermo-Couples, the remain area shall be slightly grinded. If the COMPANY request NDE for that area, MT or PT test should be carried out under COMPANY witness. If any defect is found on that area, no of sample test should be increased (2 times ).

TABLE 6-3. NUMBERS & POSITION of Thermo-Couple

Pipe size (NPS) Minimum Number and Location Up to including 10" 1 : top or bottom

2 : top and bottom (for only pipeline) Exceeding 10"

up to including 24" 2 : top and bottom

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6.9.8 Welding of Thermocouple (1) Clean any loose scale or rust from the work-piece where the wires are to be attached. (2) Clean well the point for the return lead magnet so as to reduce resistance to a minimum.

Fix the magnet as near to the Thermo-Couple position as possible. (3) Strip off the insulation from the Thermo-Couple wire to leave approximately 6 mm of

bare wire. (4) Set the output level control knob at about 80 percent. The output level meter will show

0.8 when the capacitor is charged and the ready light is glowing. (5) Grasp one of the stripped wires, about 3 – 4 mm from the end, with the tip or the jaws of

the application pliers. (6) Press the end of the wire to the work piece at 90 degree to the surface and maintain a

firm pressure. Press the charge button and wait for the ready light to glow. The output level meter should read the required preset level.

(7) Press the discharge button and wire should weld to the work-piece. There will be a sharp crack and a slight arc flash.

(8) Gently press the wire over at right angles. This is required on most jobs so as to bring out the Thermo-Couple wires along or parallel to the surface of the work piece. It also tests the weld length. If the weld shows signs of breaking, remove the wire and re-prepare the end and try again.

(9) If successful, repeat the process with the other wire, placing it approximately 6 mm away from the first.

7 HARDNESS TEST

Hardness tests of production welds and of hot bent and hot formed piping are intended to verify satisfactory heat treatment. The hardness limit applies to the weld and to the heat affected zone (HAZ) tested as close as practicable to the edge of the weld.

Exceeding 24" up to including 36"

3 : 1-top and 120 apart

Exceeding 36" up to including 48"

4 : 1-top and 90 apart

Exceeding 48" Minimum 4 but not more than 38" apart

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7.1 Requirements of hardness test

(a) Where a hardness limit is specified in Table 6-2, at least 10% of welds, hot bends, and hot formed components in each furnace heat-treated batch, and 100% of those locally heat treated shall be tested.

(b) In addition to above (a), welds in ferritic materials in following services shall be hardness tested. (1) Wet H2S service to be post-weld heat-treated (2) Amine service (3) Caustic service, when so advised

7.2 Hardness test method

7.2.1 Hardness test instrument with small indentation and digital display of hardness value; e.g Equo-tip or smaller shall be used.

7.2.2 The position and number of points to be hardness tested shall be in accordance with following Table 7-1.

7.2.3 Production hardness test is mandatory after heat treatment and shall be performed on 10% of welds in each furnace heat treatment and 100% of those which are locally heat treatment. In NACE material(H2S), any case 100%.

7.2.4 Hardness testing results shall be expressed in Brinell numbers.

7.2.5 The hardness report shall indicate actual hardness reading for the test method, type of hardness tester, personnel conducting hardness tests, type of material, and calibration.

7.2.6 Acceptance criteria of hardness test 1) Unless otherwise required hardness results shall not exceed 225 HB for P No. 1 , P. No. 3

and P No. 4 materials and 241 HB for P. No. 5 material after post weld heat treatment. 2) For sour service hardness test on P. No. 1 material shall be limited to 200 HB.

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TABLE 7-1 HARDNESS TEST POSITION & No. of TEST POINT

Pipe Size NPS(mm)

Position and No. of test point Position ① Position ② Position ③

Up to 10"

1

1

1

Exceeding 10" Up to 24"

2 (180°apart)

2 (180°apart)

2 (180°apart)

Exceeding 24" Up to 36"

3 (120°apart)

3 (120°apart)

3 (120°apart)

Exceeding 36" 4

(90°apart) 4

(90°apart) 4

(90°apart) [Note] 1. Position Legend

Position ① : The circumferential weld cap

Position ② : The edge of weld-bead (Heat-affected zone)

Position ③ : The circumferential line apart from weldment edge as distance of wall Thickness.

2. Position ① and position ② shall be located in opposite side of the weld. 3. Each place should be tested three times for Equo-tip or one time for Brinell type and average value

should be recorded

8 DOCUMENTATION

8.1 CONTRACTOR’s welding engineer will be appointed to ensure that the procedural requirements are fully complied with project requirement. The CONTRACTOR’s welding engineer will shall control and be responsible for completion of all documentation. Heat treatment chart shall be submitted to TPA to verify and endorse.

Subcontractor shall submit PWHT/Hardness test report including PWHT chart to CONTRACTOR for review and approval within 48 Hours after test. The Contractor is required to get a Company/TPA approval/certification.

Subcontractor shall carry out re-calibration for recorder and thermocouple by approved laboratory before expired date, and shall submit it to CONTRACTOR for review and approval. The Contractor is required to get the approval of the Company and certification of TPA.

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8.2 Documented information will comprise the followings.

(1) Preheat and PWHT Procedure including hardness test procedure (2) Each 1-copy of calibration certificate of temperature recorders (3) Each 1-copy of calibration certificate of wire type thermocouple per production lot (4) Temperature recorder charts during preheating and welding period (5) Heat-treatment record sheets with temperature recorder charts during PWHT (6) Reports of hardness test results

9 Attachment PWH-001: PWHT Report Form (1 sheet) PWH-002: Hardness Test Report Form (1 sheet)

FORM NO. : PWH-1

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SOUTH PARS GAS FIELD DEVELOPMENT 15 & 16

IIRCo/Sievert CONSORTIUM

POST WELD HEAT TREATMENT(PWHT) REPORT

Report No. : Test Date :

PWHT Method : [ ] Local [ ] Furnace Unit No. :

PWHT Requirements Equipments

Holding Temp.(°C ) : Recorder No : Holding Time (Hr) : Calibration Expired Date :

Heating Rate(°C/hr ) : Cooling Rate(°C/hr ) :

No. Drawing No. Joint Size Thick Mat'l H_Temp H_Time H_Rate C_Rate 1 2 3 4 5 6

HARDNESS Required Value Equipments

Calibration Expired Date : Recorder No. :

No.

Drawing No.

Joint

Size

Thick

Mat'l Test Value (HB)

Weld HAZ Base 1 2 3 4 5 6

Attachment : PWHT charter ( No. ) Remarks

PWHT Subcontractor CONTRACTOR TPA COMPANY

Sign:

Name: Date: Legend : H_Temp : Holding Temperature, H_Time : Holding Time, H_Rate : Heating Rate, C_Rate : Cooling Rate

FORM NO. : PWH-2

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SOUTH PARS GAS FIELD DEVELOPMENT 15 & 16

IIRCo/Sievert CONSORTIUM

HARDNESS TEST REPORT Project : South Pars Gas Field Development(Phases 9&10)

Report No. : Test Date :

Required Value : Unit No. : Calibration Expired Date : Recorder No. :

No.

Drawing No.

Joint

Size

Thick

Mat'l

Test Value (HB) Weld HAZ Base

1 2 3 4 5 6 7 8 9

10 11 12 13 14 15 16 17 18 19

Remarks

PWHT Subcontractor CONTRACTOR TPA COMPANY

Sign:

Name: Date:

Post Weld Heat Treatment Procedure

Documents

Transcript of Post Weld Heat Treatment Procedure