Correction Of Flange Serration 4e1y5c

WORK INSTRUCTION DEE DEVELO PMENT ENGINE ERS LTD

CORRECTION OF FLANGES SERRATION

Doc No.

DDEL/WI/SEF/001

Rev. Date

00 29.09.16

Page

Page 1 of 4

WORK INSTRUCTION FOR CORRECTION OF FLANGES SERRATION

DOCUMENT NO. DDEL/WI/SEF/001 Rev-00

DEE DEVELOPMENT ENGINEERS LIMITED

00

29.09.16

Initial Issue

REV.

DATE

DESCRIPTIO N

Achintya kr Samant a PREPARED BY (QA MANAGER)

Ajay Kumar Goel APPROVED BY (QA/QC HEAD)

DOCUMENT REVISIONS

ACCEPTED BY

WORK INSTRUCTION DEE DEVELO PMENT ENGINE ERS LTD

CORRECTION OF FLANGES SERRATION

Doc No.

DDEL/WI/SEF/001

Rev. Date

00 29.09.16

Page

Page 2 of 4

INDEX

1. 2. 3. 4. 5. 6.

SCOPE REFERENCE STANDARD RESPONSIBILITY ASSESSING IMPERFECTIONS ON FLANGE SERRATION RE-SERRATION PROCEDURE ACCEPTANCE OF FLANGE SERRATIONS

WORK INSTRUCTION DEE DEVELO PMENT ENGINE ERS LTD

1.

CORRECTION OF FLANGES SERRATION

Doc No.

DDEL/WI/SEF/001

Rev. Date

00 29.09.16

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SCOPE: Assess the imperfections on raised face flanges and carrying out correction of serration by this procedure.

2.

3.

REFERENCE STANDARD: ASME B16.5 ASME B16.47 RESPONSIBILITY: The onus of detecting imperfection and repairing those lies with Production engineer and QC engineer assigned to the project.

4.

ASSESSING IMPERFECTIONS ON FLANGE SERRATION 4.1 Permissible imperfections as per NPS are to be referred from Table 3, clause 7.3 and 7.4 of ASME B16.5 and Table 30, clause 7.1 and 7.2. Of ASME B16.47. 4.2 Imperfections shall be separated by a distance of at least 4 times the maximum radial projection. Imperfections less than half the depth of serrations shall not be considered cause for corrections. 4.3 Damage if any identified shall be marked photographed and documented in inspection report / NC. 4.4 Beyond the acceptance limits stated above, flange facing shall be re-serrated as per this procedure.

5.

RE-SERRATION PROCEDURE Assessing whether the flange facing can be machined or not: 5.1 Re-serration by machining of raised face a) Checking of Raised face height b) If the thickness of raised face is more than acceptable limit as per standard requirement then raised face shall be retooled up to depth of the imperfection and re-serrated as per the standard. c) If the thickness of raised face is not adequate to remove the imperfection and making the serration then the following process shall be followed:5.2 Machining of flange thickness to increase the height of raised face a) Measure the thickness of flange thickness : If the thickness of flange thickness is more than the acceptable limit as per standard requirement then machining the thickness of the flange thickness to increase the height of the raised face up to certain limit which is required to remove the imperfection and reserrated the raised face. 5.3 Repair by welding a) In repairing a flange face, it may be necessary to use weld metal to either fill a local area (for example, a gouge or a scratch) or to weld build up the base metal or existing weld overlay face. b) Where the flange is to be repaired by welding, the area where the build-up is to be applied shall be free of any residue, corrosion deposits, etc., that would

WORK INSTRUCTION DEE DEVELO PMENT ENGINE ERS LTD

c) d) e) f) g) h) i)

j)

6

CORRECTION OF FLANGES SERRATION

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DDEL/WI/SEF/001

Rev. Date

00 29.09.16

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unduly affect the weld. Cleaning may be by mechanical or chemical procedures Area to be repaired shall be examined prior to performing the weld build up using an appropriate NDE method to determine the integrity of the base metal. Welding procedures and welder qualifications shall comply with the requirements of ASME section IX. The filler metal, welding technique, welder qualifications, and heat treatment (if any) shall be selected to meet service and metallurgical requirements post weld heat treatment shall be performed prior to flange face machining if required by an applicable new construction or post-construction code Post weld heat treatment is not required if the thickness of the weld metal build up is less than the maximum allowable fillet weld throat thickness Post weld heat treatment should also be carried out where service /process requirements dictate. The finished machined surface shall also be examined by MT or PT, and imperfections in excess of the standard applicable to new flanges, or as specified by the , shall be repaired and re-examined by the method that discovered the imperfection. After completion of above activities, the flange face shall be subjected to machining and re-serrated as per standard requirements.

ACCEPTANCE OF FLANGE SERRATIONS 6.1 The flange facing is inspected visually and serration is measured to Roughness average Ra standards. The standard Ra is 125-250 microns. 6.2 Under-thickness of a raised face due to refinishing shall be acceptable, provided the minimum finished height of the raised face is 0.8 mm (0.031 in.). 6.3 The corrected serrations will be checked as per standard requirements by QC Engineer and if found OK will be released for further process. 6.4 On due acceptance by Owner the same flanges will be used for piping fabrication.