REPAIR DISTORTION SHELL JOINTS

Dear Sir,
Could you send me the method of repairing the distortions in the shell and joints. How many times we can repair in a weld seam?. our client spec for peaking is 13 mm and banding is 7 mm only. we are suffering a lot . tank capacity is 20000m3.

Reply

• 

  lukman, on September 29, 2009 at 3:36 am said:

  1. Cutting weld metal using grinding machine in the buckling area vertical and horizontal weld

  2. Install Strong back according to Radius of Tank with Vertical position using Horse shoe

  3. Setting strong back to assure the plate buckling has been same with radius of tank

  4. Clean Gap of Shell Plate where Weld metal has been remove from Horizontal and Vertical weld location.

  5. Built up plate on the welding line if any length of plate has shortness because cutting of weld metal.

  6. After finish built up test weld metal with Dye Penetrant test to assure the weld is good and no crack.

  7. After all Built up finish and Gap of welding line is fine, fit up vertical joint and install stiffener / key plate in the location of buckling area

  8. After All Vertical Joint has been fit up and than weld the vertical joint, carefully from out side of Tank

  9. After finish weld from out side check the radius of buckling plate and setting again using stiffener and Key plate

  10. if Radius of Tank is “OK” continuous Back weld ( from inside tank)

  11. After finish Vertical welds and than check Peaking of Vertical welds, Measurement of Peaking must be not exceed tolerance by API 650

  12. After finis Vertical joint, conduct Horizontal joint follow same is Vertical joint procedure

  13. After all welding finish (vertical and horizontal) clean area from spatter and tack weld

  14. All Stopper and Strong back and other tools using for repair will be removed after plate cold

  15. After removed all temporary attachment to shell plate check Local deviations Peaking at Vertical weld joints and Banding at Horizontal weld joints and also roundness , refer to API 650

  16. A record or report of the Measurement and testing shall be complete and approved by Client.