Electrode Baking Procedure

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 ELECTRODE BACKING

1.SCOPE Scope of this procedure is limited to the Welding work of Condenser and Turbine Joint only 2.PURPOSE This Procedure for Baking , Drying and Storage of various Electrodes to be used for our scope Condenser and Turbine 3.APPLICABILITY This procedure is applicable for storage and baking of Electrodes used for Welding of Pipelines, Supports, Foundation plates, Water Box plate etc for condenser and Turbine. 4.REFERENCE DOCUMENTS 1) ASME Sec. II Part C ( shows SFA-5.1 for Carbon steel , SFA-5.5 for alloy steel and SFA-5.4 for Stainless steel electrodes. .SFA 5.28 for alloy steel ,SFA 5.11 for stainless steel ) 2) Approved WPS 5.EQUIPMENT AND ACCESSORIES 1) Electrode Storage Area ( Store ) 2) Backing Oven , Portable Oven 3) Register for Maintaining Records

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6.DESCRIPTION. 1) Electrodes will be received from SIEMENS through material controller or Qc Supervisors 2) Electrode stock Register will be maintained by the storekeeper. 3) Special care will be taken to avoid mixing of electrodes in the Baking Oven. Different trays will be used for different electrode and when large quantity different baking ovens will be used. 4) Electrodes will be put immediately in the Baking oven after opening the pocket. Backing temperature and time will be Maintained as per the manufacture’s recommendation and WPS and it is listed below AWS Classification

Baking temperature

Time

Holding temperature

SFA 5.1

250 – 300 ° C

2 Hrs

100°C Minimum

SFA 5.4

250 – 300 ° C

2 Hrs

100°C Minimum

SFA 5.9

250 – 300 ° C

2 Hrs

100 ° C Minimum

5) Electrodes baking ( Redrying ) Ovens will have proper air circulation arrangement and will have provision to measure the temperature of the oven by the temperature Indicator. Welders will be issued electrodes not more than for two hours consumption 6) After baking is completed the electrodes will be maintained above 100 ° C (or as per the manufacturer instruction ) in a holding oven which is duly calibrated .Welders will be issued electrodes in a portable oven capable of above mentioned Holding temperature. The portable oven electric supply will be taken from any welding machine. Electrodes remaining un- consumed at the end of the day/ shift will be returned to the Holding oven. 7) Electrodes once dried if become cold for some reasons( eg. Power cut ), will re-dried as per the same procedure. However it will not happen more than one time. 8) Electrode Baking control register will be maintained.

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7 ACCEPTENCE CRITERIA 1) Verifying the Electrode Baking records as per the procedure 2) Electrodes with damaged coating will removed from the Oven. 3) Electrodes exposed to rain or moisture will not be used. 8) RECORD Electrodes store and Baking details shall be recorded in a register and the same will be subjected to regular inspection and audit.

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