Procedure For Visual Inspection i121l

SPIC JEL ENGINEERING CONSTRUCTION LIMITED Head office / Fabrication Shop : 156, Old Mahabalipuram Road, Kumaran Nagar, Chemmancherry, Sholinganallur Post, Chennai – 600 119. INDIA. Site : Torrent Power Plant, 1100 MW Sugen Combined Cycle Power Plant, Akhakhol-Village, Kamrej, Surat- 394155 Mobile : 9925015546

PROCEDURE FOR VISUAL EXAMINATION. 1.0 PURPOSE 1.1 This procedure provides guidelines for performing Visual inspections of Weld fitups , Welding in progress and completed welds . The ultimate objective is to obtain sound welds that are acceptable within the parameters established by documents referenced below. 2.0 REFERENCE 2.1 ASME Boiler and Pressure vessel codes. Section V111 Pressure vessels, Division 1 2.2 ANSI B 31.1 , Power piping 3.0 RESPOSIBILITES 3.1 The Welding Inspector/Supervisor will be the responsible of the requirements of the contract welding procedures , Drawings , specifications and applicable codes. The welders shall be informed about requirements of the applicable references . 4.0 GENERAL INFORMATION 4.1 The welding inspector shall assure himself that the material to be used have been provided in accordance with the contract requirements. 4.2 The condition of the welded surfaces being inspected shall be suitably clean. 4.3 There shall be sufficient lighting to allow proper interpretation of visual inspection. 4.4 The welder is qualified to properly perform the applicable welding procedure specification.

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5.0 WELD FIT-UP CHECK 5.1 The surfaces to be welded shall be reasonably smooth and free from deep notches , irregularities , scale ,rust, oil, grease and other foreign material which is detrimental to welding. 5.1.1 When thermal cutting was used , the affected area will be ground to obtain a clean metal surface free of irregularities. 5.1.2 5.1.3

The weld groove shall be as that specified in the welding procedure specification. The required pre-heating will be assured prior to any thermal cutting.

5.2. piping , tubing and headers to be ed will be aligned as accurately as practical within existing circumferential tolerances on diameters, wall thickness and out of roundness. The inside diameter of pipes and tubes must be concentric. The components may be retained in position using jacks, clamps, bars, tack welds or temporary attachments. Tack welds may be incorporated into final weld provided if they are visually accepted. Alignment tolerances shall be as mentioned below. Pipe and tube internals shall be checked prior to fit-up. They should be clean and free of any obstruction. CIRCUMFRENTIAL ALIGNMENT TOLERENCES. ( ASME ) Section – Thickness.( inches )

Circumferential Alignment Tolerance

Up to ½ , inclusive ¼t Over ½ to ¾ , inclusive ¼t Over ¾ to 1 - 1/2, inclusive 3/16 inch Over 1 – ½ to 2 , inclusive 1/8 t Over 2 inch Lesser of 1/8 t or ¾ inch CIRCUMFRENTIAL ALIGNMENT TOLERENCES. ( ANSI B 31.1 The inside diameters of piping to be ed shall be ed will be aligned as accurately as practicable. Where ends are to be ed and the internal misalignment exceeds 1/16 “ , it is preferred that the component with the wall extending internally be internally trimmed as shown below. However ,the trimming shall not result in a piping component wall thickness less than the minimum design thickness and the change in contour shall not exceed 30 °

1/16 “ ( 2 mm) or less 30 ° chamfer

1/16 “ ( 2 mm ) or less 2

5.2

The root opening of the component to be ed shall be adequate to provide acceptable root penetration.

5.3

On fillet welds , the parts to be ed shall be brought as close to contract as practical , although in most instances , a small opening between parts is desirable.

6.0 CHECK DURING WELDING OPERATION 6.1 The required preheat temperature is established prior to and maintained during welding ,including tack welding. 6.2 the correct electrode and filler metals are used. 6.3 Tack welds are examined by the welder before they are incorporated in to final weld. 6.4 The inter temperature is not exceeded between es. 6.5 The surface of the weld between bead is cleaned sufficiently to assure an acceptable weld. 6.6 Low hydrogen type electrodes are properly stored in heated containers as required or they have not exceeded their allowable exposure time to the atmosphere. 6.7 Welding shall not be permitted on surfaces exposed to rain , or on any wet surfaces. 6.8 Shielding gas mixtures and flow rates shall be as specified in the applicable welding procedure specification. 6.9 Shielding gases will be of welding grade. 7.0 CHECK OF THE COMPLETED WELD 7.1 There are no visible cracks, pinholes , incomplete penetration or lack of fusion. 7.2 The surface of the welds are free of coarse ripples , from grooves , overlaps , abrupt ridges and valleys, visible slag inclusions , porosity and adjacent starts and stops. The surface of the weld metal at any point shall not fall below the surface of the ading base materials. 7.3 Under cuts do not exceed : 7.3.1 7.3.2

1/32 “ or 10 % of the wall thickness , which ever is less 1/32 “ and shall not encroach on the minimum wall thickness for ANSI B31.1 pipe.

7.4 The weld reinforcement does not exceed 1/8 “ for plate butt welds per D 1.1

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7.4.1 If the surface of the weld requires grinding to meet the above criteria , care shall be taken to avoid reducing the weld or base material thickness below the required thickness. 7.5 The faces of fillet welds are not excessively convex or concave and the weld legs are the proper length. . 7.6 All defects shall be removed by machining , grinding and chipping. All repairs shall be in accordance with the applicable welding procedure specification . Weld repair will be reExamined by the procedure required for the original examination. 7.7 Each Welder’s work is identified by name , symbol or mark adjacent to the welds or records are maintained that indicate the welder of each weld or seam. 8.0 DOCUMENTATION The results of the inspection including subsequent inspections due to repair shall be recorded on a weld inspection record form.

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