ROOT UNDERCUT

DEFECT WELD

NON VISUAL

ROOT UNDERCUT

 ROOT UNDERCUT

Because :
1. Temp metal too high.
2. Ampere root too high.
3. SPEED ROOT too low.


Result :
1. Weaken connection dilokasi defect.
2. Started erosion abrasion.
3. Voltage sliding inflict a potentially crack


Countermeasures :
1. Gouging until roots in the location of a defect in the welds and appropriate contents WPS REPAIR.


Rejected Criteria
API 1104 : If the number of a length of more than 2 “ in 12” Long welds or the length of more than ¼ long welds overall, Reject .

Accepted Criteria
ANSI B31.3 : for normal category , SEVERE CYCLIC and category D , LONGITUDINAL GOOVE don’t have UNDERCUT , for branch connection ≤ 1 mm ( 1/32 “ ) and ≤ ¼ thick normal weld.

BLOW HOLE

DEFECT WELD

NON VISUAL

BLOW HOLE

Blow Hole

Because :
1. ELEKTRODA UP DOWN
2. GAP NO CONSISTENT
3. AMPERE ROOT SWING

Result :
Started erosion abrasion.

Countermeasures :
1. Gouging until roots in the location of a defect in the welds and appropriate contents WPS REPAIR.

Rejected Criteria
API 1104 : For the use of normal or SEVERE CYCLIC must repair, if not , it’s reject. In the d is still could be accepted as long as :
1. INDIVIDUAL ≤ 1/4 “ or thick plate .
2. If the number of long in 12” lasan < ½ “.

EXCESSIVE REINFORCEMENT

DEFECT WELD

VISUAL

EXCESSIVE REINFORCEMENT

EXCESSIVE REINFORCEMENT

Because :
1. TEMP METAL LOW.
2. AMPER CAPPING LOW.
3. SPEED CAPPING LOW.
4. COLD ENVIROVMENT.

Result :
1. A rising suspicion that all the lanes of the welds ampère with low.
2. Perhaps conditions internal the welds good enough but needs to be investigated further.

Countermeasures :
1. NDT test using method RT or UT ( STRAIGHT ATAU ANGLE PROBE ). If the result is proving that suspicion , and all the problems in unloading and repair welding as WPS. Welder change to QUALIFIED.
2. If the result of the test ndt show the condition internal the welds good , so the prominent sufficient in burrs to uniform and in accordance standard.

Rejected Criteria
Rejected or accepted refrain to Conditional depends the test N.D.T. If all the lanes of welds with ampère low, the welds been rejected, and but if qualified the received on the condition protrusion on standard.



Noted :
The height REINFORCEMENT welding, MAXIMUM look HIGH LOW ( ANSI B 31.3 ) .

ROOT CRACKS

DEFECT WELD

NON VISUAL

ROOT CRACKS

 ROOT CRACKS

Because :

1. NOTCH.
2. STRESS.
3. C equivalent < 0.41 %
4. STRESS RELIEF .
5. MARTENSIT DI H.A.Z.
6. CRYSTAL GROWTH.
7. FERRITE < 5% and > 12 % STAINLESS STEEL .
8. REHEAT CRACK .
9. STRESS CORROSION CRACKING ( S.C.C ) ,Cl2 , S, H2 , CAUSTIC.
10. SHRINKAGE.

Result

1. FATAL

Countermeasures :

1. Do it FAILURE ANALYSIS To determine the cause of crack accurately.
2. If crack are in the welds, GAOUGING . setting again and repair weld as WPS REPAIR.
3. If crack are out the welds , so all material(base metal) replace to a new.

Rejected Criteria

1. Cracked a star considered not dangerous unless if to exceed 5/32 “ length.
2. A kind of crack other all rejected.

CRACK

DEFECT WELD

VISUAL

CRACK

CRACK

Because :
1. NOTCH.
2. STRESS.
3. C equivalent < 0.41 %
4. STRESS RELIEF .
5. MARTENSIT DI H.A.Z.
6. CRYSTAL GROWTH.
7. FERRITE < 5% and > 12 % STAINLESS STEEL .
8. REHEAT CRACK .
9. STRESS CORROSION CRACKING ( S.C.C ) ,Cl2 , S, H2 , CAUSTIC.
10. SHRINKAGE.

Result
1. FATAL

Countermeasures :
1. Do it FAILURE ANALYSIS To determine the cause of crack accurately.
2. If crack are in the welds, GAOUGING . setting again and repair weld as WPS REPAIR.
3. If crack are out the welds , so all material(base metal) replace to a new.

Rejected Criteria
1. Cracked a star considered not dangerous unless if to exceed 5/32 “ length.
2. A kind of crack other all rejected.