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qc in pipeline welding -7

qc in pipeline welding

Add to this clause the following:
A change in the flux size grading shall also constitute an essential variable. (Mod.) Speed of travel
A change in the range of speed of travel or electrode run-out length, shall constitute an essential variable. (Sub.) Preheat
Change the title to: Preheat, and inter pass temperature
A change in preheat or inter pass temperature ranges shall constitute an essential variable. Welding current or heat input
Any change outside the specified ranges of currents or heat inputs shall constitute an essential variable. (Add.) Number and sequence of weld beads
A change in the minimum number of the weld beads deposited or the sequence of deposition shall constitute an essential variable. (Add.) Number of welders
A change in the number of root pass or hot pass welders shall constitute an essential variable. (Add.) Type and removal of line-up clamp
Removal of the line-up clamp at a stage earlier than the approval procedure, and change in type of line-up clamp shall constitute an essential variable. (Add.)(qc in pipeline welding)

5.6 Testing of Welded Joints – Butt Welds
5.6.1 Preparation
a) Non-destructive testing of test welds
On completion of welding, all procedure qualification test pieces shall be left cold for at least 48 hours and shall then be subjected to NDT in accordance with Sections 8 and 9 of this standard. This shall be carried out prior to sectioning for mechanical testing. Post-weld heat treatment, if required, shall be performed after 48 hours has elapsed, but before NDT is performed.

The NDT shall consist of:
– Visual examination, with the aid of optical instruments where necessary, to determine the dimensions of indications (refer to (9.7)).Magnetic particle testing as specified in (9.4).

– Radiographic testing in accordance with (9.3), supplemented, if specified by the Company, by ultrasonic testing in accordance with (9.6). This supplementary ultrasonic testing shall always be carried out for test welds made in whole or in part by the GMAW, GTAW or FCAW processes

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pipeline welding inspection grade -6

pipeline welding inspection grade

For non-pipeline welding, a change in the pipe manufacturing process, an increase in the base material specified minimum yield stress of more than 50 N/mm2 or an increase in the carbon content or carbon equivalent of 0.03% or greater, shall constitute an essential variable. (Sub.) Joint design
A major change in joint design (for example, from V groove to U groove) or any change outside the specified joint design tolerances constitutes an essential variable. Changes within the specified tolerances of the joint design (angle of bevel, root face thickness and root gap) are not essential variables. (Sub.)

pipeline welding inspection grade Wall thickness
Change the title to: Pipe diameter and wall thickness
A change in outside diameter outside the range 0.75 D to 1.5 D and/or any change in thickness outside the range 0.75 t to 1.5 t constitute essential variables, unless otherwise specified by the company. (Sub.) Filler metal
The following changes in filler metal constitute essential variables:

a) A change from one filler metal group to another (see Table 1).

b) A change from one consumable manufacturer and/or trade name, or AWS classification to another.

c) A change in the diameter of electrode or filler metal.

d) A change in the minimum specified yield strength of the filler metal. (Sub.) Shielding gas and flow rate
A change from one shielding gas to another or from one mixture to another constitutes an essential variable. A flow rate of the shielding gas outside the range specified and qualified also constitutes an essential variable. (Sub.) Shielding flux
Replace footnote a) of Table 1 as follows:
a) Any combination of flux and electrode in Group 4 may be used to qualify a procedure. The combination shall be identified by its complete AWS classification number, such as F71-EL-12 or F63-EM12K. Any change in either wire or flux manufacturer and/or AWS classification number shall constitute an essential variable.

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quality inspection pipeline-5 Cleaning and/or grinding
The WPS shall state the methods to be used for inter-run cleaning, final weld surface preparation and treatment to back-side of the weld, if any. The type of tools (power, manual, or both) shall be specified. (Sub.) Pre-and post-heat treatment
Add to this clause the following:
WPS shall include inter pass temperature (maximum). And similar measures shall be taken to specify and monitor weld inter pass temperatures.. (Mod.) Shielding flux
The type of shielding flux, the name of the flux manufacturer and the flux identity and/or brand name shall be designated. (Sub.) Speed of travel
Add to this clause the following:
Alternatively, for shielded metal arc welding (SMAW) the range of electrode run-out length for each pass in each electrode size shall be clearly specified. Speed of travel or electrode run-out length shall be within a range of + 10%of the nominal value for the specified electrode type and size as stipulated by the manufacturer. (Mod.) Heat input range
The allowable range of heat input rates to be applied by the welding processes for each weld bead shall be clearly specified. The units to be used shall be kilojoules per millimeter (kJ/mm) based on the following formula:

Heat input (kJ/mm) =Volts × Amps/1000 × Welding Speed (mm/sec) Number of welders
For pipeline girth welds the WPS shall designate:

a) The number of root pass welders.

b) The number of hot pass welders. See(7.1). Partially complete joint
The minimum number of passes before the joint is allowed to cool to ambient temperature and action required for partially completed welds. (Add.) Removal of line-up clamp
The stage at which line up clamp is removed. (See 7.3). (Add.)

5.4 Essential Variables
5.4.2 Changes requiring requalification Base material
Unless agreed otherwise by the company for pipeline welding, a change of pipe manufacturer, manufacturing process or steel specification/grade shall constitute an essential variable. In addition, requalification shall be required if the carbon content or carbon equivalent exceeds the value qualified by more than 0.03.

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welding in pipeline quality control -4

welding in pipeline quality control

5.2 Record
Add to this clause the following:
Qualified procedures shall be recorded by the contractor and submitted to the company. (Mod.)

5.3 Procedure Specification
5.3.2 Specification information Pipe and fitting materials
The contract materials to which the procedure applies shall be identified on the WPS. Grouping of materials of different pipe manufacturers, supply condition, diameter, wall thickness or steel specification/grade shall not be done unless agreed by the Company.

Where contract materials have been supplied in the same dimensions by more than one manufacturer, a qualification test may be performed using two pipes form different manufacturers. This may be used to qualify the procedure for use on the pipes from each manufacturer provided the specified range and number of tests in the heat affected zone are taken from both sides of the weld.

welding in pipeline quality control

For steel grades with increased susceptibility to delayed hydrogen cracking due to welding, such as with a SMYS of 555 MPa or higher, the WPS may be designed to prevent such cracking from occurring. The welding of these grades of pipe may also require the use of low hydrogen electrodes, PWHT, and a delay period prior to inspection (Sub.) Diameters and wall thicknesses
Procedures shall be qualified for each combination of diameter and nominal wall thickness of contract materials. Joint design
Add to this clause the following:
The specification shall indicate the allowable tolerances on each of the joint design details. Permanent backing shall not be used. (Mod) Filler metal and number of beads
Details of the filler metal sizes, classification and manufacturer/brand identity shall be given together with a sketch showing the location, minimum number, deposition sequence and characteristics (stringer or weave) of each weld bead. Electrical characteristics Add to this clause the following:

Additionally, the aim voltage and amperage for each bead shall be stated. The ranges of voltage and amperage shall not vary from the aim values by more than + 10 percent. (Mod.) Time between passes
Add to this clause the following:
For pipeline butt welds this time be 5 minutes or less. (Mod.)

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pipeline welding quality control -3

pipeline welding quality control

Unidentifiable, damaged, wet, rusty or otherwise contaminated or deteriorated consumables shall not be used.

4.2.3 Shielding gases Types
Add to this clause the following:
Unless otherwise indicated by the Company the maximum variation of specified gas additions, e.g. 5 percent carbon dioxide, shall be + 10 percent of the value stated. The moisture content shall correspond to a dew point not exceeding -30°C. (Mod.) Storage and handling
Add to this clause the following:
All shielding gas containers shall have clear identification labels which include the gas type. (Mod.)

5.1 Procedure Qualification
Before production welding is started, detailed Welding Procedure Specifications shall be prepared. Prior to carrying out qualification testing, Welding Procedure Specifications shall be submitted to the Company for review.

Welding procedures shall be tested to demonstrate that acceptable welds can be made by the procedure. The quality of the welds shall be determined by both non-destructive and destructive testing, as specified in (5.6). The welding procedure qualification testing (WPQT) shall be witnessed by the Company. Only qualified and approved welding procedures shall be used for production welding.

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pipeline welding quality inspection part 2

pipeline welding quality inspection


ISO 148 “Steel-Charpy Impact Test (Vnotch)

ISO15156 “Sulfide Stress Cracking Resistant Metallic Materials for Oilfield Equipment”


MR 0175 “Sulfide Stress Cracking Resistant Metallic Materials for Oilfield Equipment “(Mod)

3.2 Definition of Terms and Abbreviations
Change the title to Definition of Terms and Abbreviations” and Add clause no. 3.3.

3.3 Abbreviations
FCAW Flux Cored Arc Welding

GMAW Gas Metal Arc Welding

GTAW Gas Tungsten Arc Welding

HAZ Heat Affected Zone

HV 10 Vickers Hardness (10 kg load)

IF Incomplete Fusion

IFD Incomplete Fusion Due to Cold Lap

IIW International Institute of welding

IP Inadequate Penetration Without High-Low

IPD Inadequate Penetration Due to High-Low

IQI Image Quality Indicator

MSV Millisievert

NDT Non Destructive Testing

REM Roentgen Equivalent Mean

SMAW Shielded Metal Arc Welding

SMYS Specified Minimum Yield Stress

WPQT Welding Procedure Qualification Test (ing)

WPS Welding Procedure Specification

pipeline welding quality inspection

4.1 Equipment
Add to this clause the following:
Adequate means for measuring welding current and voltage shall be provided. Meters, independent of the welding set, shall be used.

4.2 Materials
4.2.1 Pipe and fittings
Add to this clause the following: xxxx

4.2.2 Filler metal Type and size
Consumables shall conform to one of the following specification:

AWS A5.1

AWS A5.5

AWS A.5.17

– AWS A 5.18

– AWS A 5.20

AWS A 5.28

– AWS A 5.29

All welding consumables shall be selected to produce welds with yield strength exceeding that specified for the parent material. Where steels with different specified properties are joined the weld metal yield strength shall match or exceed that of the higher strength grade.

For sour service applications the deposited weld
metal shall comply with the requirements of
NACE MR0175/ISO15156.

If low-hydrogen electrodes are selected the diffusible hydrogen content shall not exceed 10 ml/100 g in the resulting deposited weld metal. Storage and handling of filler metals and fluxes
Electrodes shall be supplied fully sealed packages and stored in a dry storage room with a maximum relative humidity of 50 percent. All manual types of electrodes shall be properly identifiable up to the time of usage, each electrode being distinguishable by proper coding. If the coding is destroyed by baking, handling, or other causes, the electrodes shall not be used.

Low hydrogen electrodes shall not be stored in heated cabinets containing electrodes of other types, such as rutile or organic type electrodes.

Wire spools for automatic and semi-automatic processes shall be stored in cabinets with supplier wrapping not removed and remain clearly identifiable up to the time of usage. Unidentifiable wire shall not be used.

Filler metals and fluxes shall be handled and stored in accordance with the manufacturers recommendations.

Each batch of flux and wire shall be labeled with the information from the supply container.

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