C7 Code and Standard

The welding may be done by a shielded metal-arc welding, submerged arc welding, gas tungsten-arc welding, gas metal-arc welding, flux-cored arc welding, plasma arc welding, oxyacetylene

UNIVERSITY KUALA LUMPUR

Fabrication and Joining Technology

Study Guide Chapter 7: Code and Standard

Contents

7.1 Introduction 3

7.2 Contetnts in API 1104, 19th edition 4

7.3 Section 1 - General 5

7.4 Section 2 – Reference Publication 6

7.5 Section 3 - Definition of Terms 7

7.6 Section 4 – Specification 7

7.7 Section 5 - Qualification of Welding Procedures for Welds Containing

Filler Metal Additives

7

7.8 Section 6 - Qualification of Welders 7

7.9 Section 7 - Design and Preparation of a Joint for Production Welding 8

7.10 Section 8 – Inspection and Testing For Production Welds 8

7.11 Section 9 - Acceptance Standards For Nondestructive Testing 8

7.12 Section 10 – Repair and Removal of Defects 8

7.13 Section 11 – Procedures for Non Destructive Testing 9

7.14 Section 12 – Automatic Welding 9

7.15 Section 13 – Automatic Welding Without Filler Metal Additions 9

7.2 Acceptance Standard for NDT (API 1104, 1999 Section 9), page 21 9

7.1 Introduction

The materials are of little use if we cannot, by use of an effective QA system trace them from

specification and purchase order to final documentation package handed over to the Client

All materials arriving on site should be inspected for:

•Size / dimensions

•Condition

•Type / specification

In addition other elements may need to be considered depending on the materials form or shape

There are a number of different types of standards that are generally written by consensus standards writing bodies These bodies are made up of volunteers who are experts in the field and represent all facets of the industry The standards are written and presented for public review and vote so that they truly become the best consensus documents with wide expertise These standards fall into 6 major categories: Codes are generally associated with a process and they spell out MANDATORY use of materials or actions Specifications likewise are mandatory but they are generally associated with a product Recommended practices and guides are documents offered as an aid to the practitioner to help

in manufacturing Classification and methods provide lists of established practices or products

7.2 Contents in API 1104, 19th Edition 1999

API standards are published to facilitate the broad availability of proven, sound engineering and operating practices These standards are not intended to obviate the need for applying sound engineering judgment regarding when and where these standards should be utilized API 1104 contains 13 sections and two appendices:

7 Design And Preparation Of A Joint For Production Welding

8 Inspection And Testing Of Production Welds

9 Acceptance Standards For Nondestructive Testing

10 Repair And Removal Of Defects

11 Procedures For Nondestructive Testing

12 Automatic Welding

13 Automatic Welding Without Filler-Metal Additions

Appendix A Alternative Acceptance Standards for Girth Welds

Appendix B In-Service Welding

API 1104

Welding of Pipelines and Related Facilities This standard covers the gas and arc welding of butt, fillet, and socket welds in carbon and low-alloy steel piping used in the compression, pumping, and transmission of crude petroleum, petroleum products, fuel gases, carbon dioxide, and nitrogen, and where applicable, covers welding on distribution systems It applies to both new construction and in-service welding The welding may be done by a shielded metal-arc welding, submerged arc welding, gas tungsten-arc welding, gas metal-arc welding, flux-cored arc welding, plasma arc welding, oxyacetylene welding, or flash butt welding process or by a combination of these processes using a manual, semi-automatic, or automatic welding technique or a combination of these techniques, The welds may be produced by position or roll welding or by a combination of position and roll welding This standard also covers the procedures for radiographic, magnetic particle, liquid penetrant, and ultrasonic testing as well

as the acceptance standards to be applied to production welds tested to destruction or inspected by

radiographic, magnetic particle, liquid penetrant, ultrasonic, and visual testing methods

7.3 Section 1 - General

This standard covers the gas and arc welding of butt, fillet, and socket welds in carbon and low-alloy steel piping used in the compression, pumping, and transmission of crude petroleum, petroleum products, fuel gases, carbon dioxide, and nitrogen and, where applicable, covers welding on distribution systems

It applies to both new construction and in-service welding The welding may be done by a shielded arc welding, submerged arc welding, gas tungsten-arc welding, gas metal-arc welding, flux-cored arc welding, plasma arc welding, oxyacetylene welding, or flash butt welding process or by a combination

metal-of these processes using a manual, semiautomatic, or automatic welding technique or a combination metal-of these techniques

This standard also covers the procedures for radiographic, magnetic particle, liquid penetrant, and ultrasonic testing as well as the acceptance standards to be applied to production welds tested to destruction

or inspected by radiographic, magnetic particle, liquid penetrant, ultrasonic, and visual testing methods

Processes other than those described above will be considered for inclusion in this standard Persons who wish to have other processes included shall submit, as a minimum, the following information for the committee's consideration:

a A description of the welding process

b A proposal on the essential variables

c A welding procedure specification

d Weld inspection methods

e Types of weld imperfections and their proposed acceptance limits

f Repair procedures

It is intended that all work performed in accordance with this standard shall meet or exceed the requirements of this standard

7.4 Section 2 - References Publication

Code – A body of laws arranged systematically for easy reference and use Because a code has a legal status, it is definition mandatory, and use words such as shall, will, and must to express certain

conditions and requirements, and to verify that those requirements are being met Examples of codes includes AWS D1.1, D1.5

Standard – Is establish for use as a rule or basis of comparing in measuring quality, quantity, content, relative value Examples AWS A30, Standard Welding Terms and Definition

Specification – Is detailed description of the parts of a whole A statement of particulars as to actual or required size, quality, performance, terms Thus, a specification describes all technical information for

a material, product, system or service and indicates hot to determine that the requirements have been met Examples AWS Filler Metal Specification A5.1 through A5.32

Recommend Practice - Is non mandatory description of generally accepted industrial methods and technique One of the most common examples is Recommended Practice No SNT-TC-1A, ASNT’s guideline to personnel qualification and certification in non-destructive examination

Guide – Provides information on proven methods to accomplish certain tasks It is not mandatory but should reflect best practices Examples AWS B1.11, Guide for the Visual Examination of Welds

Quality – Is measureable conformance to specification To establish product quality, purchasers invoke

or mandate certain codes, standards and specifications that state the requirements to which the product must conform Quality professional must be able to read, understand and apply the provision of the governing documents cited in a contract, job specification or purchase order

Code Provision – Is the specific text contained within a numbered section or subsection of a code Identify the key term or phrase that describes the issue or requirements of interest, and them locate the code provision that best addresses the issue

7.5 Section 3 - Definition of Terms

The definition of welding terms used in this API 1101 standard are as defined in AWS A3.0, Standard Welding Terms and Definitions, with additions and modifications

p sizes given in the qualified welding procedure Equipment that does not meet these requirements shall

n shall be established and qualified to demonstrate that welds with suitable mechanical properties (such

as strength, ductility, and hardness) and soundness can be made by the procedure.The quality of the we

ld shall be determined by destructive test

7.8 Section 6 - Qualification of Welders

Welders must pass a qualification test to show that they can use a given welding procedure The test should employ the same manipulative techniques that welders will use in production The welder who qualifies the PQR is also qualified as long as the welder qualification requirements detailed in API 1101 Section 6 are met

Before starting the qualification tests, the welder shall be allowed reasonable time to adjust the welding equipment to be used The welder shall use the same welding technique and proceed with the same speed

he will use if he passes the test and is permitted to do production welding The qualification of welders shall be conducted in the presence of a company representative

7.9 Section 7 - Design and Preparation of a Joint for Production Welding

The purpose of this section is to establish requirements for production welding and fabrication It requires constant attention to the specific of the welding procedure which is why it must be performed only by welders who have qualified for that procedure Welders who have been qualified for that procedure can perform welding on production weldments

7.10 Section 8 – Inspection and Testing For Production Welds

The company may dictate what kind of inspection will occur, when, how often, and may require that inspector demonstrate the effectiveness of the inspection procedure being used and their ability to use those procedure The company must keep detailed records of inspection and the certification of the personnel conducting them

7.11 Section 9 - Acceptance Standards For Nondestructive Testing

NDT testing does not hurt the serviceability or function of a part When performing a nondestructive examination, the inspector may find imperfections or discontinuities which may not require rejection of the part The acceptance standards presented in this section apply to discontinuities located by radiographic, magnetic particle, liquid penetrant, and ultrasonic test methods They may also be applied

to visual inspection Nondestructive testing shall not be used to select welds that are subjected to destructive testing in accordance To find discontinuities for evaluation, the inspector must understand how they present themselves using the inspection method

7.12 Section 10 – Repair and Removal of Defects

The company must authorize repair of defects in the root and filler beads, but need not authorize repair cover pass defects Two conditions require a qualified repair welding procedure: when the repair

employs a welding process different from that of the original weld, and when a previously repaired area is repaired again Once a weld is repaired, it must be inspected in the same manner as the original weld and meet the requirement of API 1101 section 9 Deciding whether to have just the repaired area

or the entire weld inspected is up to the company

7.13 Section 11 – Procedures for Non Destructive Testing

Some of the technologies involved in nondestructive testing of welds especially radiography and ultrasound They have similar applicability to welding Just as welding and destructive testing require the writing of qualified procedures A detailed procedure for the production of images shall be

established and recorded Radiographic film produced by the use of this procedure shall have the density, clarity, and contrast required by this standard Images produced by other systems shall have the requisite sensitivity to define clearly the essential hole or wire diameter of the proper penetrameter

7.14 Section 12 – Automatic Welding

Welding procedures for a given welding process vary with the level of automation involved The process involved SAW, GMAW, GTAW, flux core and plasma arc These procedures shall be adhered

to except where a change is specifically authorized by the company

7.15 Section 13 – Automatic Welding Without Filler Metal Additions

This section discuss about Automatic welding without filler-metal additions shall be done using the flash butt welding process These procedures shall be adhered to except where a change is specifically authorized by the company

7.2 Acceptance Standard for NDT (API 1104, 1999 Section 9), page 21

9.1 General

The acceptance standards presented in this section apply to imperfections located by radiographic, magnetic particle, liquid penetrant, and ultrasonic test methods They may also be applied to visual inspection

9.2 Rights of Rejection

All nondestructive test methods are limited in the information that can be derived from the indications they produce The company may therefore reject any weld that appears to meet these acceptance standards if, in its opinion, the depth of an imperfection may be detrimental to the weld

9.3 RADIOGRAPHIC TESTING

All imperfections and densities referred to 9.3.1 through 9.3.13 based on negative images Radiographic test can identify the following defects:

9.3.1 Inadequate Penetration Without High-Low

9.3.2 Inadequate Penetration Due to High-Low

9.3.3 Inadequate Cross Penetration

9.3.13 Pipe or Fitting Imperfections

9.4 MAGNETIC PARTICLE TESTING

9.4.1 Classification of Indications

9.4.1.1 Indications produced by magnetic particle testing are not necessarily imperfections Magnetic and metallurgical variations may produce indications that are similar to those produced by imperfections but that are not relevant to acceptability

9 5 LIQUID PENETRANT TESTING

9.5.1 Classification of Indications

9.5.1.1 Indications produced by liquid penetrant testing are not necessarily imperfections Machining marks, scratches, and surface conditions may produce indications that are similar to those produced by imperfections but that are not relevant to acceptability

9.6 ULTRASONIC TESTING

9.6.1 Classification of Indications

9.6.1.1 Indications produced by ultrasonic testing are not necessarily defects Changes in the weld geometry due to alignment offset of abutting pipe ends, changes in weld reinforcement profile of I.D root and O.D capping passes, internal chamfering, and ultrasonic wave mode conversion due to such conditions may cause geometric indications that are similar to those caused by weld imperfections but that are not relevant to acceptability

9.7 VISUAL ACCEPTANCE STANDARDS FOR UNDERCUTTING

Visual inspection involves examining materials, with or without magnification or remote examination devices such as mirrors or fiber optics

10 Repair and Removal of Defects

10.1 AUTHORIZATION FOR REPAIR

10.1.1 Cracks

Cracked welds shall be removed from the line unless permitted by 9.3.10 or when the repair is

authorized by the company Cracks may be repaired provided the length of the crack is less than 8% of the weld length and a qualified repair welding procedure is used

10.1.2 Defects Other Than Cracks

Defects in the root and filler beads may be repaired with prior company authorization Defects in the cover pass may be repaired without prior company authorization A qualified repair welding procedure

is required to be used whenever a repair is made to a weld using a process different from that used to make the original weld or when repairs are made in a previously repaired area

10.2 REPAIR PROCEDURE

When a repair welding procedure is required, the procedure shall be established and qualified to

demonstrate that a weld with suitable mechanical properties and soundness can be produced This shall

be determined by destructive testing and the type and number of such tests shall be at the discretion

of the company For repair welding procedures, consideration should be given to the use of

lowhydrogen electrodes and/or increased preheat and interpass temperatures

11 PROCEDURES FOR NDT

11.1 RADIOGRAPHIC TEST METHODS

Section 11 deals mostly with the radiographic test method, but other non destructive test methods are addressed It details the requirements for producing radiographic images on film or other media through the use of x ray or gamma rays

11.1.1 General

Subsection 11.1 presents the requirements for producing radiographic images on film or other media through the use of X-rays or gamma rays A detailed procedure for the production of images shall be established and recorded Radiographic film produced by the use of this procedure shall have the density (see 11.1.10), clarity, and contrast required by this standard Images produced by other systems shall have the requisite sensitivity to define clearly the essential hole or wire diameter of the proper penetrameter

11.2 MAGNETIC PARTICLE TEST METHOD

When magnetic particle testing is specified by the company, a detailed written procedure for magnetic particle testing shall be established that meets the requirements of ASTM E 709 The company and the nondestructive testing contractor should agree on the magnetic particle testing procedure or procedures prior to the perfonnance of production testing The company shall require the contractor to demonstrate that the proposed procedures will produce acceptable results and shall require the contractor to use such procedures for production testing

11.3 LIQUID PENETRANT TEST METHOD

When liquid penetrant testing is specified by the company, a detailed written procedure for liquid penetrant testing shall be established that meets the requirements of ASTM E 165

11.4 ULTRASONIC TEST METHODS

Section 11.4 applies to new and in service circumferential butt welds A detailed procedure must be developed, qualified by demonstration and agreed upon by the contractor and company The pipe being inspected that can interfere with scanning

11.4.1 General

When ultrasonic testing is specified by the company for the inspection of new and/or in-service circumferential butt welds, the requirements of this section shall apply A detailed procedure for use of the individual ultrasonic techniques shall be established and recorded The use of ultrasonic testing and the scope of its use shall be at the option of the company

11.4.2 Details of Procedure

The required details of a written procedure for UT of welds are provided in the subsections listed under 11.4.2

11.4.3 Ultrasonic Testing Personnel Requirements

An NDT Level III in the ultrasonic method shall develop the application technique and prepare and approve the testing procedure

11.4.4 Demonstration of the Testing Procedure

Prior to final written approval, the company shall require the contractor to demonstrate the application

of the procedure and ultrasonic systems

11.4.5 API Sensitivity Reference Standard

The sensitivity reference standards for use in measuring the screen height of return echoes from known geometric conditions (the notches in the calibration block) must be made of materials similar to those in production applications The peaks on the instrument screen that return echoes from these notches must

be 80% of the screen height

12 Mechanized Welding with Filler Metal Additions

Mechanized welding is a method of application where welding process parameters and torch guidance are controlled mechanically or electronically but may be manually varied during welding to maintain the specified welding conditions

A qualified welding procedure consists of a WPS and a procedure qualification record (PQR) API

1104 also refers to the latter as a coupon test report A PQR ‘supports’ a WPS A WPS can be

supported by more than one PQR It is common, but not mandatory to list the PQRs that support a particular WPS

12.4 PROCEDURE SPECIFICATION

12.4.1 General

Only the welding variables that are applicable to the welding process and welding method to be used need to be documented All of the applicable welding variables described in 12.4.2 must be included in the WPS

12.5 ESSENTIAL VARIABLES

12.5.1 General

API 1104 allows some degree of departure from the variables used to qualify a WPS However,

departures from variables that affect the mechanical properties or soundness of completed welds are not allowed without requalification by preparing and testing another weld These latter variables are

referred to as essential variables

12.6 QUALIFICATION OF WELDING EQUIPMENT AND OPERATORS

The purpose of this section is to allow welding operators to demonstrate their ability to make

acceptable welds using the qualified procedure and the equipment that will be used in production welding

12.7 RECORDS OF QUALIFIED OPERATORS

The company must maintain records of test results for each welding operator Figure 2 in API 1104 is a sample PQR, which can also be used as a WQTR The use of Figure 2 is not mandatory, although a form similar to this should be used It is common, but not mandatory, to include a space for a revision number, which may be required eventually The company must also maintain a list of operators

12.8 INSPECTION AND TESTING OF PRODUCTION WELDS

See guidance provided in Section 8 The first sentence of 8.2 indicates that nondestructive testing may consist of radiographic testing (RT) or another method specified by the company The preferred method

of inspection for many mechanized welds is automated ultrasonic testing (AUT) Even though AUT is not mentioned in Section 8, this is not intended to preclude the use of AUT on mechanized pipeline girth welds

12.9 ACCEPTANCE STANDARDS FOR NONDESTRUCTIVE TESTING

See guidance provided in Section 9 or Appendix A, as appropriate

12.10 REPAIR AND REMOVAL OF DEFECTS

See guidance provided in Section 10

12.11 RADIOGRAPHIC TESTING

For RT, see guidance provided in 11.1 UT is the preferred method for many mechanized welds and should be performed in accordance with 11.4 Even though UT is not mentioned in 12.11, this is not intended to preclude the use of UT on mechanized pipeline girth welds

13 Automatic Welding Without Filler metal Additions

13.1 ACCEPTABLE PROCESSES

Automatic welding without filler-metal additions shall be done using the flash butt-welding process

13.2 PROCEDURE QUALIFICATION

Procedure qualification requirements in Section 13 for flash butt-welding are similar to those in

Section 5 for manual or semiautomatic welding and Section 12 for mechanized welding except that at least two test welds are required and destructive testing must be proceeded by radiographic testing (RT)

G13.3 RECORD

A qualified welding procedure consists of a WPS and a procedure qualification record (PQR) API

1104 also refers to the latter as a coupon test report A PQR ‘supports’ a WPS

G13.4 PROCEDURE SPECIFICATION

All of the applicable welding variables described in 13.4 must be included

G13.5 ESSENTIAL VARIABLES

G13.5.1 General

API 1104 allows some degree of departure from the variables used to qualify a WPS However,

departures from variables that affect the

G13.6 QUALIFICATION OF EQUIPMENT AND OPERATORS

The purpose of this section is to allow welding operators to demonstrate their ability to make

acceptable welds using the qualified procedure and the equipment that will be used in production welding

G13.7 RECORDS OF QUALIFIED OPERATORS

The company must maintain records of test results for each welding operator Figure 2 in API 1104 is a sample PQR, which can also be used as a WQTR The use of Figure 2 is not mandatory, although a form similar to this should be used It is common, but not mandatory, to include a space for a revision number, which may be required eventually The company must also maintain a list of operators and the procedures for which they have qualified

G13.8 QUALITY ASSURANCE OF PRODUCTION WELDS

Quality assurance of production welds made using the flash butt-welding process is normally

accomplished by removing and testing selected production welds, monitoring the welding sequence using a strip chart recorder, nondestructive testing, measurement of reinforcement height, and

monitoring post- post-weld heat treatment using a strip chart recorder

G13.9 ACCEPTANCE STANDARDS FOR NONDESTRUCTIVE TESTING

For flash butt welds, acceptance criteria are provided only for isolated slag inclusions Since no reference is made to acceptance criteria for other imperfections, these appear to be unacceptable regardless of their size

Discussion Question

1 Which welding process may be done in common application in industry for the permitted process?

2 Which NDT may be done in common application in industry for the permitted technique?

3 API 1104 applies to the welding of pipe and fittings that conform to which specification?

4 Atmospheres for shielding an arc may consist of :

5 Which of the following represent changes in essential variables for a manual welding procedure?

6 A welding procedure test is being performed on 3 inch schedule 80 pipe (0.300” wall) What is the total number of specimens required for testing?

7 For procedure qualification, the exposed surfaces of each nick-break specimen shall

8 What is the criteria to test fillet-welded joints for qualification of a welding procedure?

9 The bend test shall be considered acceptable if:

10 The exposed surfaces of each fillet-weld-break specimen shall show:

Tutorial

Section 4 – Specification

1 Filler metals are classified by the American Welding Society (AWS) and ASME according to their chemical composition and assigned a corresponding Filler Number or F-No The type of filler metal must be specified by manufacturer The AWS has set up the following AWS classification numbers for steel oxyacetylene gas welding rods (OAW)

a What does the “RG-65” filler material classification designate?

b API 1104 Table 1 Section 5 divides filler metals into nine groups based on electrode

characteristic and the process that employ those electrodes List the characteristic and the classifications of the filler metal as shown in Table 1