ROOT POROSITY

DEFECT WELD

NON VISUAL

ROOT POROSITY

Root Porosity

Because :
1. The condition of the root damp or moist.
2. Electrode moist
3. Purging gas contaminated ( GTAW )
4. No purging gas ( GTAW )

Result :
1. Weaken Connection weld.
2. Started erosion abrasion.
3. Started INTERNAL CORROSION.

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

Rejected Criteria
1. INDIVIDUAL more than 1/8 “ or 25 % minimum thick .
2. The distribution of goods more than the stipulated API 1104 picture 15 and 16.
3. For Cluster Porosity diameter more than 1/2 “ , total length porosity 12 “ Welding more than 1/2 “

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INCOMPLETE PENETRATION (IP)

DEFECT WELD

NON VISUAL

INCOMPLETE PENETRATION

INCOMPLETE PENETRATION

Because :
1. GAP too narrow
2. Ampere root low
3. Welding machine not Calibration
4. The electrodes up and down
5. GAP dirty

Result :
1. Notch potential crack.
2. weaken weld joint.
3. 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 : 1. INDIVIDUAL > 1 “ , 2. Total length 12 “ welding > 1 “ , total length of weld 12 “ length weld > 8% length weld.
• If IP potential HIGH LOW : 1If side of the root of open > 2” ( INDIVIDUAL ) , 2. In 12” length weld , total length > 3” .

Accepted Criteria

• ANSI B 31.3 : 1. INDIVIDUAL ≤ 1 mm ( 1/32 “ ) and ≤ 0.2 X weld thicknes normal . 2. Total length of weld 6 “ ≤ 38 mm ( 1 ½ “ )

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EXCESS WIRE

DEFECT WELD 

NON VISUAL 

EXCESS WIRE 

EXCESS WIRE 

Because :
1. WELDING WIRE COROTION
2. WIRE FEEDER NOT NORMAL .
3. Electricity supply disconnected breaking up

Result :
1. NOTCH POTENTIAL CRACK.
2. DAMAGE CLEANING PIG

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

Rejected Criteria  :
Rejected its existence

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ROOT UNDERFILL

DEFECT WELD

NON VISUAL

ROOT UNDERFILL

ROOT UNDERFILL

Because :
1. Gap dirty..
2. Ampere root low.
3. Temp metal cold.
4. HIGH LOW.

Result :
1. Notch potential crack.
2. Damage cleaning pig.

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.

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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.

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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 “.

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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 ) .

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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.

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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.

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EXCESSIVE PENETRATION

DEFECT WELD

NON VISUAL

EXCESSIVE PENETRATION

EXCESSIVE PENETRATION

Excess weld metal protruding through the root of a fusion (butt) weld made from one side only.

With pipe welding this type of imperfection may cause effects in the fluid flow that can cause erosion and/or corrosion problems.



Common causes
Penetration becomes excessive when the joint gap is too large, the root faces are too small, the heat input to the joint is too high or a combination of these causes.



Acceptance
The criteria which sets the level of acceptable penetration depends primarily on the application code or specification.

• BS 2971 (Class 2 arc welding) requires that the 'penetration bead shall not exceed 3mm for pipes up to and including 150mm bore or 6mm for pipes over 150mm bore'.
• BS 2633 (Class 1 arc welding) gives specific limits for smaller diameters pipes, eg for pipe size 25-50mm the maximum allowed bore penetration is 2.5mm.
• ASME B31.3 bases acceptability on the nominal thickness of the weld, for instance, allowing for a thickness range of 13-25mm up to 4mm of protrusion. However, ASME notes that 'more stringent criteria may be specified in the engineering design'.
• BS EN ISO 5817 (Quality levels for imperfections), which supersedes BS EN 25817, relates the acceptable protrusion to the width of the under-bead as follows:

Avoidance
It is important to ensure that joint fit-up is as specified in the welding procedure. If welder technique is the problem then re training is required.

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ROOT CONCAVITY

DEFECT WELD

NON VISUAL

ROOT CONCAVITY

ROOT CONCAVITY

Because :
1. Gap too wide
2. SPEED ROOT too high .
3. AMPERE ROOT high
4. ELEKTRODA too big.
5. For STAINLESS STEEL ROOT GTAW In override in topped with GTAW So that root melted again and sucked up by the process of caping.


Result
1. Started erosion abrasion.
2. S.C.C ( CL2 , NaOH ).
3. weaken weld join .


Countermeasures :
1. GOUGING until the root , setting again and repair welding as WPS Repair.



Rejected Criteria
API 1104 :
1) IF INDIVIDUAL > ¼ INCI,
2) SEPANJANG TEBAL PIPA ,
3) all length welding 12” > ½ “ .



ANSI B 31.3 : The depth of root concavity acceptable when the number of connection plus welding reinforcement > thick nominal ( T W ) b). in 12” length weld > 3inch

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HIGH LOW

DEFECT WELD

(VISUAL) 

HIGH LOW

High Low

Because :
1. Any setting
2. Different thick

Result :
1. Started erosion abrasion.
2. Producing a voltage sliding potential to crack

Countermeasures :
1. The prominent part in an oblique 1 : 3 ( ASME VIII ) 1 ; 2.5 ( ANSI B31.3 )

Rejected Criteria
1 ANSI B31.3 : t ≤ ¼ “ max. 1.5 mm ( 1/16 “ ) EXTERNAL t > ¼ ~ ≤ 13 mm ( ½ “ ) , max. 3 mm ( 1/8” )t > 13 mm ( ½ “ ) ~ ≤ 25 mm ( 1” ) ,max 4 mm ( 5/32 “ ) t > 25 mm ( 1 “ ) , max 5 mm ( 3/16 “ )
INTERNAL = 2 X EXTERNAL exceeds the maximum mentioned above, if no do it, rejected

2. API 1104 :

a). If any side of weld opened >2inch individual.
b). in 12” length weld > 3inch

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STOP START

DEFECT WELD

(VISUAL)

STOP START

stop start

Because :

• Bulge recurring caused by replacement electrodes too backward so there overlapping prominent.
• The empty without capping in a recurrent manner caused by the replacement of electrodes too forward.

Result
1. THE STANDOUT LOOKS BAD AND INEFFICIENT
2. That empty inflict NOTCH Potentially crack.

Countermeasures :
1. Prominent grinding sufficient in to the standard
2. Thr empty grinding must be to rest of slag missing , then welds rearranged wps repair

Rejection criteria :
1 .To prominent recurring acceptable on the condition in burrs to the form of standard.

2 .To empty acceptable origin repaired by filling capping to the form of a welds uniform .If this mentioned above not carried out , the welds rejected

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UNDERFILL

DEFECT WELD

(VISUAL)

UNDERFILL

Underfill

Because
1. Metal temperatures too low.
2. Ampère capping too low.
3. Dirty.
4. Swing not fix.
5. HIGH LOW.

Result
1. arise NOTCH Potentially crack.
2. Weaken connection weld.
3. Started rust the surface.

Countermeasures :
Grinding until defect missing, Welds repeated according WPS repair.

Rejection criteria :
If defect weld not repaired , the welds is rejected.

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UNDERCUT

DEFECT WELD

(VISUAL)

UNDERCUT

UNDERCUT

Because
1. Temperature metal too high .
2. Ampère capping high .
3. Speed capping too low

Result
1. Weaken connection.
2. Started rust the surface.
3 .Cause voltage sliding ( displacement stress ) potential to crack .

Countermeasures :
1. Enough clean up with wire brush and filling it with stringer ( welding lane single without swing according wps repair.

Rejection criteria :
1. The depth of more than 1/32 “or more than12 ½ % thick nominal material.
2. The depth of more than 1/64” to 1/32 “or more than 6% to 12 ½ % thick nominal material.
3. A length of more than 2 “ in 12 “ Welds or more than 1/6 length weld.
4. ROOT UNDER CUT more than 2” in 12 “ ROOT or more than 1/4 length ROOT .

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SURFACE COLD LAP

DEFECT WELD

(VISUAL)

SURFACE COLD LAP

SURFACE COLD LAP

Because
1. Temperature metal low.
2. Capping ampère low.
3. Swing not fixed.
4. The surface of the material dirty.

Result
1. Is incomplete fusion Potentially crack.
2. Arising suspicion that all lane welds been implemented ampère low so as to lead to fusion between elementary substance with the welds or inter lane imperfect.

Countermeasures :
1. If suspicion not proved , then cold laps sufficient in grindstone with the uniform.
2. If suspicion proven and all the troubled demolished ,repair welding as WPS repair .
3. If it is still troubled,Change welder.

Rejection criteria :
The existence of surface cold laps were rejected and must be repaired.

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PIN HOLE

DEFECT WELD

(VISUAL)

PIN HOLE

PIN HOLE

Because
1. Formed for welding as gas: CO2 , CO , NO2 , SO2.
2. The wind getting into the area welds.

Result
The possibility of leak high at the defect.

Countermeasures :
Defect in gouging to roots welds, Then fills weld appropriate wps repair.

Rejection criteria :
The existence of defect Pin Hole rejected and must be repaired any size.

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SURFACE CONCAVITY

DEFECT WELD 

(VISUAL)

SURFACE CONCAVITY 

SURFACE CONCAVITY

Because :

1. Angles openings joint too large. 
2. Electrodes too small. 
3. Ampère capping high. 
4. Lane capping unfinished. 
5. Speed capping too high

Result

1. Weaken weld joint. 
2. Started rust the weld profile. 
3. Arising displacement stress potentially crack.

Countermeasures :
Directly finish lanes capping appropriate WPS .


Rejection criteria :
If are not repaired , the welds is rejected

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POROSITY

DEFECT WELD 

(VISUAL)

POROSITY

Defect Weld : Porosity

Because :

1. Environmental wet or moist.
2. The galvaniize not yet been grinding .
3. Elektoda moist.
4. A rising gas when welding prosses.
5. Ampere capping too high .
6. The wind getting into the area welds.
7. Welding-joint dirty.

Result

1. Bad Profile.

2. Weaken weld joint.

3. Started rust the surface.

Countermeasures :

Grinding or gouging to defect missing, Welds repeated according WPS repair

Rejection criteria :

1. Individually to exceed 1/8” or 25% nominal thickness.

2. For cluster porosity Diameter more than ½”.

3. The number of long clusters in 12” weld more than ½”.

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Spatters

DEFECT WELD
(VISUAL)

SPATTERS

Defect Weld : Spatters

Because :

1. Environmental wet or moist.
2. Elektoda moist.
3. The wind getting into the area welds.
4. The arc welding too long .
5. Capping current too high.
6. Kind of a current wrong.
7. Kinds of polarity wrong.
8. The galvaniize not yet been grinding.

Result :

1. Bad Profile
2. Started rust the surface

               

Countermeasures :
1 . Use chisel only or niggardly churlish .Do not use grindstone because it is going to take the base metal

Rejection criteria : If not cleared can cause rejection (Because it is not relevant with standard)

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