weld evaluation guide _radiografia_[1].pdf

8/10/2019 Weld Evaluation Guide _RADIOGRAFIA_[1].pdf

1/20

WELD DISCONTINUITY EVALUATION GUIDE

.

1

SPECIAL NOTES

1.

Radiographic films only show defects in two dimensions. Depth cannot be easilydetermined by R.T.

2.

100% radiography and spot radiography are quality level designations used by the

ASME Pressure Vessel Code and can be used to evaluate other methods of NDE.

3.

For API 1104, The maximum accumulation of discontinuities is 2" in any 12" of weld

or 8% of weld length excluding High-low and undercutting. (9.3.12)

Codes and Regulations

1.ASME Section VIII, Division 1. "Pressure Vessels"

2.

ASME B31.3 "Chemical Plant and Petroleum Refinery Piping"

3.

API 650 "Welded Steel Tanks for Oil Storage ". Now follows ASME VIII Div. 1

requirements.

4.

API 1104, "Standard for Welding Pipelines And Related Facilities"

5.

ASME B31.4 "Liquid Transportation System for Hydrocarbons, Liquid Petroleum Gas,

Anhydrous Ammonia & Alcohols". Now Follows API 1104 Requirements.

6.

ASME B31.8, "Gas Transmission and Distribution Piping Systems" Follows API 1104

Requirements.

Ing. Jorge Eliecer Rueda DanielsCel: 0416-8705030


2/20


.

2

Internal Concavity

ASME Section VIII - Div 1

Smoothly contoured concavity permitted if equal

reinforcement is provided (UW-35.d)

ASME B31.3

Shall not reduce the total thickness of the joint,

including reinforcement to less than the thickness of

the thinner of the components being joined. Total joint

thickness including weld reinforcement > =t

(Table 341.3.2)

API 1104

Density of any area exceeding the density of the

thinnest adjacent base metal is unacceptable. (9.3.6.)


3/20


.

3

Slag Inclusions

ASME Section VIII - Div 1 100% Radiography

Material thickness Max. slag length

2 1/4" 3/4"

Max total Length = t in 12t

(UW-51.b.2 and b.3)

ASME Section VIII - Div 1 Spot Radiography

Max length of 2/3t

Max total length t in 12t of weld

Max width of 3/32" or 1/3t (UW-52.c.2)

ASME B31.3 Severe Cyclic Conditions

Max length 1/3t


Max width of 3/32" or 1/3t (The lesser)

(Table 341.3.2)

ASME B31.3 Normal Fluid Service

Max length 2t

Max total length 4t in 6" of weld

Max width of 1/8" or 1/2t (The lesser) (Table 341.3.2)

API 1104

Max width 1/13", The total accumulated length shall

not exceed 8% of the weld length. Isolated inclusions

are not exceed 2" in any continuous 12" for pipe 2

3/8" O.D. and larger. For pipe O.D. less than 2 3/8"

inclusions are limited to 3 times the thinnest of the

pipes being joined (9.3.8)

t = Wall thickness


4/20


.

4

Slag Inclusions

ASME Section VIII - Div 1 100% Radiography

Material thickness Max. slag length

2 1/4" 3/4"


(UW-51.b.2 and b.3)


Max length of 2/3t




Max length 1/3t



(Table 341.3.2)


Max length 2t


Max width of 1/8" or 1/2t (The lesser)(Table 341.3.2)

API 1104

Max width 1/13", The total accumulated length shall

not exceed 8% of the weld length. Isolated

inclusions are not exceed 2" in any continuous 12" for pipe 2 3/8" O.D. and larger. For

pipe O.D. less than 2 3/8" inclusions are limited to 3 times the thinnest of the pipes being

joined (9.3.8)

t = Wall thickness


5/20


.

5

Excessive Root Penetration


Material thickness Max Height

1/16" to 3/32" 1/32"

>3/32" to 3/16" 1/16">3/16" to 1/2" 5/32"

>1/2" to 1" 3/16"

>1" to 2" 1/8"

>2" to 3" 5/32"

>3" to 4" 7/32"

>5" 5/16"

(UW-35,d)

ASME B31.3

Material thickness Max Height

1/4" to 1/2" 1/8"

>1/2" to 1" 5/32"

Over 1" 3/16"

(Table 341.3.2)

API 1104Not Covered


6/20


.

6

Incomplete Fusion


None Allowed (UW-51,b,1)

ASME B31.3None Allowed (Table 341.3.2)

API 1104

Root pass: Maximum 1" length of 12" of weld or

9% of total weld length (9.3.4)

Sidewall of between beads (cold-lap): Max length

per indication < 2", 2" in 12" of weld and

total length or any indications not to exceed 8%

of total weld length (9.3.5)


7/20


8/20


.

8

Incomplete Penetration Due to High-Low

ASME Section VIII - Div1

None allowed (UW-51,b,1)

ASME B31.3None allowed (Table 341.3.2)

API 1104

Max individual length: 1"

Max accumulated length of 3" in 12" of continuous

weld (9.3.2)


9/20


.

9

Cracks




API 1104Shallow Crater crack or star crack not be

longer than 5/32". Shallow Crater crack or

star cracks are located at the stopping point of

weld beads and are result of weld metal

contractions during solidification.

Cracks of any size or location in the weld are

not allowed


10/20


.

10

Cracks




API 1104

Shallow Crater crack or star crack not be

longer than 5/32". Shallow Crater crack or

star cracks are located at the stopping point of

weld beads and are result of weld metal

contractions during solidification.


not allowed


11/20


.

11

Cracks




API 1104Shallow Crater crack or star crack not be longer

than 5/32". Shallow Crater crack or star cracks

are located at the stopping point of weld beads

and are result of weld metal contractions during

solidification.


not allowed


12/20


.

12

Misalignment


Mat. Thickness Long. Max. Circum. Max.

3/4" to 1-1/2" 1/8" 3/16"

>1-1/2" to 2" 1/8" 1/8 t

>2" Lesser of 1/16 t or 3/8" 1/8t or 3/4"

(UW-33a)

ASME B31.3

Inside diameters of components at end to be joined

must be aligned within engineering desing and

welding procedure ( WPS ). (the lesser of 1/4 t or3/16" recommended). If the external surfaces of the

two components are not aligned, the weld shall be

tapered between the surfaces. (328.4.3)

API 1104

The offset should not exceed 1/8"

Greater offset caused by dimensional variations

shall be equally distributed around the

circumference of the pipe. (7.2)


13/20


.

13

Tungsten Inclusions

ASME Section VIII - Div 1 100% RadiographyMaterial thickness Max slag length

2 1/4" 3/4"


(UW-51.b.2 and b.3)


Max length of 2/3t




Max length 1/3t



(Table 341.3.2)


Max length 2t


Max width of 1/8" or 1/2t (The lesser)(Table 341.3.2)

API 1104

Max width 1/13", The total accumulated length

shall not exceed 8% of the weld length. Isolated

inclusions are not exceed 2" in any continuous 12"

for pipe 2 3/8" O.D. and larger. For pipe O.D. less

than 2 3/8" inclusions are limited to 3 times the thinnest of the pipes being joined (9.3.8)

t = Wall thickness


14/20


.

14

Porosity

ASME Section VIII - Div 1 100% RadiographyMaximum size for any indication shall be the

lesser of 1/4t or 5/32". Isolated indications

separated by at least 1" is the lesser of 1/3t or1/4". For t >2" The maximum acceptable size is

3/8" (Appendix 4)

ASME Section VIII - Div 1. Spot Radiography

Rounded indications are not a factor in the

acceptability of welds if that welds not required

to be fully radiographed.

(UW-52,(c),(3))


Maximum size for any indication shall be the


separated by at least 1" is the lesser of 1/3t or

1/4". For t >2" The maximum acceptable size is

3/8". Not surface porosity allowed.

ASME B31.3 Normal Fluid ServiceFor t < 1/4", requirements are the same as for

severe cyclic conditions. For t > 1/4"requirements are 1.5 times those for severe cyclic

conditions. Not surface porosity allowed.

API 1104

Max dimension 1/8" or 25% of weld thickness,

whichever is smaller, (9.3.9.2) Cluster: Max

area of 1/2" diameter. Max individual pore 1/16". Max 1/2" length in 12" of weld.

(9.3.9.3) Hollow bead: Max length 1/2". Max 2" length in 12" of weld with individual

discontinuities exceeding 1/4" in length separated by at least 2". The total accumulated

length shall not exceed 8% of weld length (9.3.9.4)


15/20


.

15

External Concavity


Smoothly contoured concavity permitted if equal

reinforcement is provided (UW-35.d)

ASME B31.3

Shall not reduce the total thickness of the joint,

including reinforcement to less than the thickness of

the thinner of the components being joined. Total

joint thickness including weld reinforcement > =t

(Table 341.3.2)

API 1104

Density of any area exceeding the density of the

thinnest adjacent base metal is unacceptable. (9.3.6.)


16/20


.

16

Burn - Through

ASME Section VIII - Div 1Not Covered, see Undercut

ASME B31.3Not covered, see Incomplete penetration

API 1104Maximum dimension shall not exceed 1/4" or

the thinnest of the pipe wall thickness being

joined. Not film density exceed that of

thinnest adjacent base material. Total of

maximum dimensions in 12" of weld shall not

exceed 1/2"

(9.3.7.2)


17/20


.

17

Undercut - Cap Pass

ASME Section VIII - Div1

The weld must be free of coarse ripples, grooves,

over laps, abrupt ridges or valleys. Any thickness

reduction due to welding shall not exceed the lesserof 1/32" or 10% of adjoining wall thickness.

(UW-35(a) and (b)(1) and (2))


Not allowed (Table 341.3.2)


Max Depth of 1/32" or 25% of wall Thickness,

whichever is smaller, Not allowed longitudinal butt

joints. (Table 341.3.2)

API 1104

Total length of undercut shall not exceed 2" in 12"

of weld.

The total accumulations shall not exceed 1/6 of the

weld length (9.3.11)

For mechanical measurement when is available

Depth > 1/32" o >12.5% of wall thickness,

whichever is smaller, the undercut is not allowed.Depth >1/64" or between 6% and 12.5% of wall

thickness whichever is smaller, length: 2" I any

continuous 12" weld length or 1/6 the weld length,

whichever is smaller.

Depth =< 1/64" or =< 6% of pipe wall thickness

whichever is smaller, the undercut is acceptable,

regardless of length. (9.7.1)


18/20


.

18

Porosity

ASME Section VIII - Div 1 100%

Radiography


lesser of 1/4t or 5/32". Isolated indicationsseparated by at least 1" is the lesser of 1/3t or

1/4". For t >2" The maximum acceptable size

is 3/8" (Appendix 4)



acceptability of welds if that welds not

required to be fully radiographed.

(UW-52,(c),(3))





1/4". For t >2" The maximum acceptable size

is 3/8". Not surface porosity allowed.

(Table 341.3.2)


severe cyclic conditions. For t > 1/4"

requirements are 1.5 times those for severe

cyclic conditions. Not surface porosity

allowed. (Table 341.3.2)

API 1104

Max dimension 1/8" or 25% of weld thickness, whichever is smaller, (9.3.9.2) Cluster:

Max area of 1/2" diameter. Max individual pore 1/16".

Max 1/2" length in 12" of weld. (9.3.9.3)

Hollow bead: Max length 1/2". Max 2" length in 12" of weld with individual

discontinuities exceeding 1/4" in length separated by at least 2".

The total accumulated length shall not exceed 8% of weld length (9.3.9.4)


19/20


.

19

Undercut - Root Pass


The weld must be free of coarse ripples, grooves,

over laps, abrupt ridges or valleys. Any thickness

reduction due to welding shall not exceed the lesserof 1/32" or 10% of adjoining wall thickness.

(UW-35(a) and (b)(1) and (2))


Not allowed (Table 341.3.2)


Max Depth of 1/32" or 25% of wall Thickness,

whichever is smaller, Not allowed longitudinal butt

joints. (Table 341.3.2)

API 1104

Total length of undercut shall not exceed 2" in 12"

of weld.

The total accumulations shall not exceed 1/6 of the

weld length (9.3.11)

For mechanical measurement when is available

Depth > 1/32" o >12.5% of wall thickness,

whichever is smaller, the undercut is not allowed.Depth >1/64" or between 6% and 12.5% of wall

thickness whichever is smaller, length: 2" I any

continuous 12" weld length or 1/6 the weld length,

whichever is smaller.

Depth =< 1/64" or =< 6% of pipe wall thickness

whichever is smaller, the undercut is acceptable,

regardless of length. (9.7.1)


20/20

WELD DISCONTINUITY EVALUATION GUIDE 20

Porosity

ASME Section VIII - Div 1 100% RadiographyMaximum size for any indication shall be the


separated by at least 1" is the lesser of 1/3t or1/4". For t >2"

The maximum acceptable size is 3/8"

(Appendix 4)



acceptability of welds if that welds not required to

be fully radiographed.

(UW-52,(c),(3))





1/4". For t >2" The maximum acceptable size is

3/8". Not surface porosity allowed.

(Table 341.3.2)


severe cyclic conditions. For t > 1/4"

requirements are 1.5 times those for severe cyclic

conditions. Not surface porosity allowed.

(Table 341.3.2)

API 1104

Max dimension 1/8" or 25% of weld thickness, whichever is smaller, (9.3.9.2) Cluster:

Max area of 1/2" diameter. Max individual pore 1/16".

Max 1/2" length in 12" of weld. (9.3.9.3)

Hollow bead: Max length 1/2". Max 2" length in 12" of weld with individual

discontinuities exceeding 1/4" in length separated by at least 2".

The total accumulated length shall not exceed 8% of weld length (9.3.9.4)

weld evaluation guide _radiografia_[1].pdf

Documents