An Introduction to Mechanical Testing for Welding Procedure Specifications

General:

WPS/PQR Qualification aims is to ensure that the fabricator’s welding procedures are qualified before the job application, We cover the welding jobs performed in the production of platforms and pipelines and other miscellaneous work.

WPS/PQR Qualification

The WPS for both the main welding procedures and weld repair procedures of an oil and gas project shall be submitted. It can be submitted by CONTRACTOR to Client / COMPANY hopefully one-month minimum before the start of qualification tests. The WPS shall be accompanied by a summary table showing:

• The process
• Consumables
• The direction of welding
• Type of weld
• WPS number
• Test weld wall thickness
• Scope of qualification

The welding procedure qualification tests shall not be undertaken until the COMPANY’S authorized representatives or members approve the WPS’s principle

The CONTRACTOR must show, through qualification tests, that their WPS meets or exceed the quality required. Welding procedure qualifications shall be required for the pipe-to-pipe welds including:

• Fillet welds
• Fittings to pipes
• Fittings to fittings
• All associated weld repairs
• The test welds must be entirely visually inspected and then non-destructively tested.
• All welding procedure qualification tests shall be conducted in the presence of the COMPANY Inspector.
• COMPANY shall accept and approve all welding processes, systems, and procedures.
• The COMPANY Inspector shall witness all non-destructive examinations. As well as destructive testing and review and approve all related results. All mechanical testing shall be carried out by a certified testing facility subject to prior approval of the COMPANY.

The Welding Engineer

The Welding Engineer of the fabricator shall be responsible for:

• conducting the welding procedure tests per A.W.S. D1.1/ASME SEC IX or any other standard as applicable;
• conducting all relevant mechanical tests as per the appropriate standard and Customer requirements;
• Preparing the welding procedure qualification documents.

All welding procedures of the fabricator shall be qualified, as per International standards such as:

A.W.S. D1.1 – For structural work;

ASME SEC.IX– For piping and pressure vessel work;

API 1104– For pipeline work.

Welding of Test Joints

• The welding equipment shall be the same as or equivalent to that intended for use during fabrication/installation.
• Materials used in the tests shall be selected and subject to Inspector’s prior approval.

F.A.Q.

What is the main reason for carrying out a Welding Procedure Qualification?

By welding according to the given parameters, we will create a joint that meets all of the design requirements.

What is the main reason for conducting a Welder Qualification Test?

To test the ability of a welder to follow verbal or written instructions. As well as verify that the weld produced meets the required standard.

Terminology

WPS – Weld Procedure Specification:

• Qualified instructions on how to complete the weld
• A WPS is a written (qualified) welding procedure prepared to provide direction for the making of production welds

P.Q.R. – Procedure Qualification Record (ASME) & WPAR – Weld Procedure Approval Record:

Record of the welding parameters and test results:

• A PQR is a record of welding data used to weld a test coupon

Welder Qualification Test certificate & Welder Performance Qualification (ASME):

• Record of Welder test results and range of approval

pWPS – Preliminary Welding Procedure Specification

WPAR – Welding Procedure Approval Record is a statement of the results of accessing each test piece, including re-tests.

Certifying Authority (C.A.)/ 3rd party – Customer-appointed inspection agency for the project, such as A.B.S., B.V., D.N.V., Lloyd’s, R.P.S., etc.

Mechanical Properties Test

The amount of deformation which metal can withstand under different modes of force application

• Malleability: Ability of a material to withstand deformation under static compressive loading without rupture
• Ductility: The ability of a material to undergo plastic deformation under static tensile loading without rupture. Measurable elongation and reduction in cross-section area
• Toughness: Ability of a material to withstand bending or the application of shear stresses by impact loading without fracture.
• Hardness: Measurement of a materials surface resistance to indentation from another material by static load
• Tensile Strength: Measurement of the maximum force required to fracture a materials bar of unit cross-sectional area in tension

Tests for required properties:

• Tensile tests (Transverse Welded Joint, All Weld Metal)
• Toughness testing (Charpy, Izod)
• Hardness tests (Brinell, Rockwell, Vickers)
• Bend testing
• CTOD (Crack Tip Opening Displacement)
• Corrosion tests, H.I.C. & SOHIC Tests

Tests for weld quality

• Macro testing
• Fillet weld fracture testing
• Buttweld nick-break testing
• NDE (VT,PT,MT,RT,UT)

Codes, Standards, and Customer Specifications/Requirements

For example, the following summarizes the code/standard/specification requirements that must be learned. It must be learned before attending the mechanical tests in laboratory testing for WPS / PQR qualification for:

• Piping
• Pipeline
• Structural systems in an oil and gas project

Reduced Section Tension Test

Type of Test: Reduced Section Tension Test

Description of Test:

Tensile testing is also known as tension testing. It is a fundamental materials science test in which a sample is subjected to controlled tension until failure.

Pipeline and Piping System

• Client Specs
• Reference Code: API 1104 latest edition
• Test Method: API 1104 latest edition

Structural

• Client Specs
• Reference Code: A.W.S. D1.1 latest edition

Bending test (Transverse Specimen)

Type of Test: Bending Test

Description of Test:

Bend testing determines the ductility or the strength of a material by bending the material over a given radius. The sample is inspected for cracks on the outer surface following the bend. Bend testing provides insight into the modulus of elasticity and the bending strength of a material.

Pipeline and Piping System

• Client Specs
• Reference Code: API 1104 latest edition
• Test Method: API 1104 latest edition

Structural

• Client Specs
• Reference Code: A.W.S. D1.1 latest edition

Nick Break Test

Type of Test: Nick Break Test

Pipeline and Piping System

• Client Specs
• Reference Code: API 1104 latest edition
• Test Method: API 1104 latest edition

Structural

• Client Specs
• Reference Code: A.W.S. D1.1

Charpy Impact Test (Weld Joint Section)

Type of Test: Charpy Impact Test (Weld Joint Section)

Description of Test:

ISO “Metallic materials — Charpy pendulum impact test” specifies the Charpy pendulum impact (V‑notch and U‑notch) test method for determining the energy absorbed in an impact test of metallic materials

The test consists in breaking with one blow from a swinging pendulum. Under defined conditions, a test piece V-notched in the middle and rested on two supports. The energy absorbed is determined.

Pipeline and Piping System

• Client Specs
• Reference Code: API 1104 latest edition

Structural

• Client Specs
• Reference Code: A.W.S. D1.1 latest edition
• Test Method: ASTM E23-07a E1

Vickers Hardness Number (H.V.), Load test 5 Kgf & Macro Examination and Photo

Pipeline and Piping System

Type of Test: Vickers Hardness Number (H.V.), Load test 5 Kgf

Description of Test:

ISO 6507-1 “Metallic materials — Vickers hardness test — Part 1: Test method” specifies the Vickers hardness test method for the three different ranges of test force for metallic materials.

A diamond indenter in the form of a right pyramid with a square base and with a specified angle between opposite faces at the vertex is forced into the surface of a test piece. It is followed by a measurement of the indentations’ diagonal length of the on the surface after the removal of the test force, F.

• Client Specs
• Reference Code: API 1104 latest edition
• Test Method : ASTM E384 latest edition

Type of Test: Macro Examination and Photo

• Client Specs
• Reference Code: API 1104: the latest edition
• Test Method : ASTM E340 latest edition

Steps – witness mechanical testing of the samples in a certified and approved testing facility :

• Specimen Preparation
• Specimen Visual Check / Dimension Measurement
• Mechanical Testing
• Preliminary Report Review

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