Visual Inspection Procedure

OPERATIONAL DOCUMENT

VISUAL INSPECTION PROCEDURE

Code: Revision: Edition: Page

VISUAL INSPECTION PROCEDURE (VT)

Signature

0

07/09/2015

Creation

Anis Samet

Ezzeddine BEN KRAIEM

Anis Samet

01

30/10/2015

Revision

Anis Samet

Ezzeddine BEN KRAIEM

Anis Samet

Rev.

Date

Description

Issued by

Verified by

Eng

DO-TEC-104 01 10/15 1 / 8

Approved by




Eng

DO-TEC-104 01 10/15 2 / 8

SUMMARY

1.

SCOPE ........................................................................................................................................................ 3

2.

REFERENCE DOCUMENTS ..........................................................................................................................3

3.

AIDS TO VISUAL INSPECTION .....................................................................................................................3

4.

EQUIPMENTS .............................................................................................................................................. 4

5.

PERSONNEL ................................................................................................................................................4

6.

LIGHTING .................................................................................................................................................... 4

7.

PRIOR TO WELDING ....................................................................................................................................4

8.

DURING WELDING .......................................................................................................................................5

8.1

Inner run cleaning ......................................................................................................................................5

8.2

Inter pass temperature ...............................................................................................................................5

9.

AFTER WELDING .........................................................................................................................................6

10.

REPAIR ....................................................................................................................................................6

11.

EVALUATION ...........................................................................................................................................6

APPENDIX 1: VISUAL INSPECTION REPORT




Eng

DO-TEC-104 01 10/15 3 / 8

1. SCOPE This procedure relates to the visual inspection requirements for the weld of new construction, adjacent base metal and the control of the parameters and features of the weld and how these are recorded, in order to ensure full compliance with the relevant approved welding procedures, codes and specifications. Visual inspection will be performed to 100% of pipeline girth welds, prior to, during and post welding. 2. REFERENCE DOCUMENTS -

BS EN ISO 17637-2011: non-destructive testing of welds-visual testing of fusion-welded joints

-

SNT-TC-1A, 2011 edition: American Society for Nondestructive Testing, Recommended Practice.

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ISO 9712, 2012 edition: Non-destructive testing. Qualification and certification of NDT personnel. 3. AIDS TO VISUAL INSPECTION

Direct visual examination may usually be made when access is sufficient to place the eye within 24 inches of the surface to be examined and at an angle not less than 30° to the surface to be examined.

Aids to visual inspection should be used whenever practicable to facilitate the assessment of imperfections or the examination of welds not directly visible. These aids may be in various forms depending on the type and location of the weld being examined. For local examination of a weld that is directly visible to the eye, a small hand lens used in conjunction with a pen torch, while varying the direction of the light is usually very revealing. In such cases, the hand held lens shall have a magnification of 3x to 5x. 4. EQUIPMENTS All equipment to be used to assist visual inspections shall, where applicable, be fully calibrated and have a valid calibration certificate. When it is required to measure the dimensions of a weld edge preparation, a weld or an imperfection or the material parameters, the following devices may be used: 

Welding gauges



Caliper



Magnifier



Ruler



Torch lamp




Eng

DO-TEC-104 01 10/15 4 / 8

5. PERSONNEL Visual welding inspector shall be suitably qualified to a recognized international standard for the inspection and shall check the welding activities referring to the appropriate WPS, Quality Plans, Specifications and Codes to ensure full compliance. Visual Inspectors personnel shall have as minimum requirements one of the following qualifications or equivalent: ASNT Level II Visual Inspection (American Society of Nondestructive Testing)



CSWIP 3.1



Welding Inspector (Certification Scheme for Welding and Inspection Personnel)

All visual examination personnel shall have a minimum of 2 years’ experience on visual examination. They shall be capable of reading standard Jaegar Chart J1 letters with or without corrected vision. The far vision acuity shall be 20/40 or better. Yearly eye examination shall be conducted. 6. LIGHTING The inspection area shall be adequately illuminated, with a minimum level of 1000 lux, for proper evaluation. If artificial lighting is used such as a torch, the direction of the light shall be capable of being varied so that any imperfections can be revealed and glare or dazzling of the inspector avoided. 7. PRIOR TO WELDING Before welding starts, the Inspector shall: 

Have adequate knowledge of the applicable standard



Have adequate knowledge of the welding procedure specification (WPS) to be used



Have a knowledge with working drawing

The inspector shall check as a minimum: 

Examine the welders’ qualification



Review materials and welding consumables to be used.



Check base metal for discontinuities.



Check weld preparation



Check fit-up and alignment of weld joints.



Check preheats, if required.

Weld Preparation: Check that the form and dimensions of the weld preparation are in accordance with the data supplied using appropriate measuring devices.




Eng

DO-TEC-104 01 10/15 5 / 8

Fit – Up: Check that the fit-up (gap and alignment) of the parts to be welded, including any backing material, is in accordance with the data supplied. Welding consumables: check the identification of the welding consumable against the appropriate welding procedure specification. Preheat: 75 °C preheat temperature will be checked at not less than 75mm from the weld line. The pre-heating temperature may be checked by the use of temperature indicating crayons or paints, thermometers, thermocouples, pyrometers or a combination of these methods. 8. DURING WELDING During welding, there are a number of items, which require control so that the resulting weld will be satisfactory. Visual examination is the primary method for controlling this aspect of the fabrication. It can prove to be a valuable process control tool. Some of the aspects of fabrication, which can be checked, include: 

Welding technique



Welding consumable



Preheat temperature



Direction of welding



Inter pass cleaning and temperature



Sequence of weld passes.



Quality of weld root bead.



Subsequent layers for apparent weld quality.



Welding process amperage, voltage & polarity



Travel speed and heat input



Cleaning between passes.

Any of these factors, if ignored, could result in discontinuities that could cause serious quality degradation. 8.1 Inner run cleaning Check that each run of weld metals cleaned before it is covered by a further run. Particular attention shall be paid to the junctions between the weld metal and the fusion faces. 8.2 Inter pass temperature Check the conditions specified in the welding procedure for inter pass temperature.




Eng

DO-TEC-104 01 10/15 6 / 8

9. AFTER WELDING 

Finished weld appearance



Dimensional accuracy



Post-weld heat treatment (if required)

The basic purpose of final weld inspection is to assure the weld’s quality. Check that all slag has been removed, by manual or mechanical means. The surfaces of the finished welds shall be sufficiently free from coarse ripples, grooves, overlays and abrupt ridges and valleys to permit proper interpretation of radiographs and other required non-destructive examination. Melt through and repaired burn through areas are acceptable provided the areas do not contain cracks, crevices, excessive oxidation and the root convexity and concavity limits are not exceeded. The weld and adjacent parent metal shall be examined for any local hot spots or cracking caused by stray arching. Weld seam and heat affected zone (HAZ) shall be examined for flaws against the acceptance standard. In some cases, visual inspection may not be sufficient to determine the full extent of a surface flaw (crack/porosity) and the use of other testing methods may be required before the flaw can be assessed. 10. REPAIR The weld fails to comply wholly or in part with the acceptance criteria, the unacceptable defects shall be removed. The following items shall be checked during the repair operation. Ensure that the specified means of removing the defect (e.g. chipping, grinding, machining, thermal cutting or thermal gouging) shall be used correctly, when a thermal process is employed. Check that if pre-heating is specified and is correctly applied. Partially removed weld: Check that the cut out portion is sufficiently deep and long enough to completely remove the defects. The ends and sides of the cut should gradually from the base of the cut to the surface of the weld metal. The width and profile of the cut should allow adequate access for re-welding. Completely removed weld: when a section of material containing a faulty weld has been removed, check that each weld preparation is repaired in accordance with the welding procedure. Re-welding shall be carried out in accordance with the relevant repair welding procedure and full re-inspection shall be made for the repaired weld. 11. EVALUATION The weld shall be evaluated according to the acceptance standards of the BS EN ISO 17637-2011.



Table 1: Acceptance criteria


Eng

DO-TEC-104 01 10/15 7 / 8



APPENDIX 1 VISUAL INSPECTION REPORT


Eng

DO-TEC-104 01 10/15 8 / 8

Visual Inspection Procedure

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