API-41

Questions and Answers

What is the required width of the completed weld compared to the original groove width?

Equal to the original groove width

Twice the original groove width

1/8 in. (3 mm) wider (correct)

1/8 in. (3 mm) narrower

Where should welding be maintained in relation to the pipe?

In the middle of the pipe

Anywhere on the pipe surface

At or near the top of the pipe (correct)

At or near the bottom of the pipe

What may be used to inspect welds for imperfections?

Destructive testing only

Nondestructive means only

Nondestructive means or by removing welds for mechanical tests (correct)

Visual inspection only

What should each welder do to identify their work?

Identify their work as prescribed by the company Signup and view all the answers

When should preheat and PWHT practices be followed?

When specified in the welding procedure specification Signup and view all the answers

What may be used for nondestructive testing (NDT)?

Radiographic testing or other methods specified by the company Signup and view all the answers

What may be involved in destructive testing?

Removal of completed welds and examination of specimens Signup and view all the answers

What may happen to welders failing to comply with requirements?

They may be disqualified from further work Signup and view all the answers

What qualification is required for welding inspection personnel?

Qualified by experience and training, with documentation retained by the company Signup and view all the answers

What certification level should NDT personnel have?

Level I, II, or III according to recognized national certification programs Signup and view all the answers

What abilities must NDT personnel demonstrate?

Near-distance acuity and color differentiation abilities Signup and view all the answers

What do acceptance standards for NDT apply to?

Imperfections located by radiographic, magnetic particle, liquid penetrant, and ultrasonic test methods Signup and view all the answers

What is considered a defect in API Standard 1104 if ESI and ISI indications exceed 8% of the weld length?

ESI and ISI indications exceeding 8% of the weld length Signup and view all the answers

Under what conditions are slag inclusions considered defects in small diameter pipes according to API Standard 1104?

Under specified conditions Signup and view all the answers

How is porosity defined in API Standard 1104?

Gas trapped by solidifying weld metal before it can escape to the surface Signup and view all the answers

What are the criteria for individual or scattered porosity defects in API Standard 1104 based on?

Size and distribution limitations Signup and view all the answers

What is hollow bead porosity defined as in API Standard 1104?

Elongated linear porosity occurring in the root pass Signup and view all the answers

What are the criteria for cluster porosity defects in the finish pass based on in API Standard 1104?

Diameter and aggregate length Signup and view all the answers

How are cracks in the weld defined as defects in API Standard 1104?

With specific size and location conditions Signup and view all the answers

What causes shallow crater cracks or star cracks according to API Standard 1104?

Weld metal contractions during solidification Signup and view all the answers

Under what conditions is undercutting considered a defect in API Standard 1104?

Under specified conditions Signup and view all the answers

What is considered a defect if there is an accumulation of imperfections in a continuous 12 in. length of weld exceeding 2 in. or 8% of the weld length?

Accumulation of imperfections exceeding 2 in. or 8% of the weld length Signup and view all the answers

What is the required clearance around the joint for all position welds?

Adequate clearance Signup and view all the answers

What should the crown surface of the completed weld not fall below?

Outside surface of the pipe Signup and view all the answers

What is the alignment requirement for roll welding?

Maintained by the use of skids or a structural framework Signup and view all the answers

What is the maximum allowed raise of the crown surface above the parent metal for roll welding?

1/16 in. (1.6 mm) Signup and view all the answers

What is the definition of Incomplete Fusion (IF) according to API Standard 1104?

A surface imperfection between the weld metal and the base material that is open to the surface Signup and view all the answers

What is the definition of Internal Concavity (IC) as per API Standard 1104?

A subsurface imperfection and is acceptable if the density of the radiographic image does not exceed that of the thinnest adjacent parent material Signup and view all the answers

When is a burn-through (BT) considered a defect for large diameter pipes according to API Standard 1104?

If the maximum dimension exceeds 1/4 in. (6 mm) and the density in any portion of the BT’s image exceeds that of the thinnest adjacent parent material Signup and view all the answers

When are slag inclusions considered a defect for large diameter pipes according to API Standard 1104?

If the length of an elongated slag inclusion (ESI) indication exceeds 2 in. (50 mm), or if the aggregate length of ESI indications in any continuous 12 in. (300 mm) length of weld exceeds 2 in. (50 mm) Signup and view all the answers

When are parallel ESI indications considered a single indication according to API Standard 1104?

Unless the width of either of them exceeds 1/32 in. (0.8 mm), in which case they shall be considered separate indications Signup and view all the answers

What is the API Standard 1104's criteria for determining defects in welding?

Specific criteria for determining defects in welding, including length and aggregate length of indications, and the maximum dimensions for different types of imperfections Signup and view all the answers

What is the maximum allowed height difference between the crown surface and the parent metal for position welding?

1/8 in. (3 mm) Signup and view all the answers

What is the purpose of maintaining alignment in roll welding using skids or roller dollies?

To prevent sag in the supported lengths of pipe Signup and view all the answers

How much wider should the face of the completed weld be compared to the width of the original groove for position welding?

Approximately 1/8 in. (3 mm) Signup and view all the answers

How should two beads be started for position welding?

Not at the same location Signup and view all the answers

Study Notes

Welding Defects and Inspection Criteria in API Standard 1104

API Standard 1104 specifies criteria for evaluating welding defects in pipelines and related facilities
ESI and ISI indications exceeding 8% of the weld length are considered defects
For small diameter pipes, slag inclusions are considered defects under specified conditions
Porosity is defined as gas trapped by solidifying weld metal before it can escape to the surface
Criteria for individual or scattered porosity defects include size and distribution limitations
Cluster porosity in the finish pass is considered a defect based on diameter and aggregate length
Hollow bead porosity is defined as elongated linear porosity occurring in the root pass
Criteria for hollow bead porosity defects include length and aggregate length limitations
Cracks in the weld are considered defects with specific size and location conditions
Shallow crater cracks or star cracks are the result of weld metal contractions during solidification
Undercutting, defined as a groove melted into the parent material adjacent to the toe or root of the weld, is considered a defect under specified conditions
Any accumulation of imperfections in a continuous 12 in. length of weld exceeding 2 in. or 8% of the weld length is considered a defect

API Standard 1104: Welding Defects and Acceptance Criteria

Inadequate Cross Penetration (ICP) is a subsurface imperfection between the first inside pass and the first outside pass caused by inadequately penetrating the vertical land faces.
Incomplete Fusion (IF) is a surface imperfection between the weld metal and the base material that is open to the surface.
Incomplete Fusion Due to Cold Lap (IFD) is an imperfection between two adjacent weld beads or between the weld metal and the base metal that is not open to the surface.
Internal Concavity (IC) is defined as a subsurface imperfection and is acceptable if the density of the radiographic image does not exceed that of the thinnest adjacent parent material.
Burn-through (BT) is a portion of the root bead where excessive penetration causes the weld puddle to be blown into the pipe.
For large diameter pipes, a burn-through (BT) shall be considered a defect if the maximum dimension exceeds 1/4 in. (6 mm) and the density in any portion of the BT’s image exceeds that of the thinnest adjacent parent material.
For small diameter pipes, a burn-through (BT) shall be considered a defect if the maximum dimension exceeds 1/4 in. (6 mm) and the density in any portion of the BT’s image exceeds that of the thinnest adjacent parent material, or if more than one BT of any size is present.
Slag inclusions are nonmetallic solids entrapped in the weld metal or between the weld metal and the parent material.
For large diameter pipes, slag inclusions shall be considered a defect if the length of an elongated slag inclusion (ESI) indication exceeds 2 in. (50 mm), or if the aggregate length of ESI indications in any continuous 12 in. (300 mm) length of weld exceeds 2 in. (50 mm).
For large diameter pipes, slag inclusions shall also be considered a defect if the width of an ESI indication exceeds 1/16 in. (1.6 mm), or if the aggregate length of isolated slag inclusion (ISI) indications in any continuous 12 in. (300 mm) length of weld exceeds 1/2 in. (13 mm).
Parallel ESI indications separated by approximately the width of the root bead (wagon tracks) shall be considered a single indication unless the width of either of them exceeds 1/32 in. (0.8 mm), in which case they shall be considered separate indications.
The API Standard 1104 provides specific criteria for determining defects in welding, including length and aggregate length of indications, and the maximum dimensions for different types of imperfections.

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Description

Test your knowledge of welding defects and inspection criteria in API Standard 1104 with this quiz. Learn about various types of defects such as porosity, cracks, incomplete fusion, and slag inclusions, and understand the specific acceptance criteria for different types of imperfections in welding.