General:
The purpose of WPS/PQR Qualification is to ensure that the fabricator’s welding procedures are qualified before the job application, per the Customer’s requirements. This post covers the welding jobs performed in the production of platforms (including the structures) and pipelines and other miscellaneous work at the fabricator yard for oil and gas projects.
WPS/PQR Qualification
The WPS for both the main welding procedures and weld repair procedures of an oil and gas project shall 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 no., test weld wall thickness, and 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.
CONTRACTOR shall demonstrate by qualification tests that the proposed WPS and the equipment he intends to perform welding and weld repairs meet the quality and properties required in this specification. Welding procedure qualifications shall be required for the pipe-to-pipe welds and all other welds, including fillet welds, fittings to pipes, fittings to fittings, and all associated weld repairs.
- The test welds shall 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 and 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 to be used in the tests shall be selected and subject to Inspector’s prior approval.
F.A.Q.
Weld Procedure
Question: What is the main reason for carrying out a Welding Procedure Qualification?
Answer: To show that following a given set of parameters will produce a welded joint that has the properties that satisfy the design requirements
Welder Qualification
Question: What is the main reason for conducting a Welder Qualification Test?
Answer: To test the ability of a welder to follow verbal or written instructions and verification 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 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, also known as tension testing, 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 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 by one blow from a swinging pendulum, under defined conditions, a test piece V-notched in the middle, and resting 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, followed by a measurement of the diagonal length of the indentation left in the surface after 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