An Introduction to Mechanical Testing for WPS / PQR Qualification

Intro-Mechtest

General:

The purpose of WPS/PQR Qualification is to ensure that the welding procedures are qualified by the fabricator prior to the application on the job, in accordance with the Customer 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 an oil and gas project shall be submitted by CONTRACTOR to Client / COMPANY normally one month minimum before the start of qualification tests. The WPS shall be accompanied by a summary table showing: process, consumables, 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 Inspector (COMPANY’S authorized representatives or members) has given his approval of the principle on the said WPS.

CONTRACTOR shall demonstrate by qualification tests that the proposed WPS as well as the equipment he intends to use enable performance of welds and weld repairs meeting the quality and properties required in this specification. Welding procedure qualifications shall be required for pipe to pipe welds but also for all other welds including fillet welds, fittings to pipes, fittings to fittings and all associated weld repairs.

  • The test welds shall be fully visually inspected and then non-destructively tested.
  • All welding procedure qualification tests shall be conducted in the presence of the COMPANY Inspector.
  • COMPANY shall give final acceptance and approval of all welding processes, systems and procedures.
  • The COMPANY Inspector shall witness all non-destructive examinations and destructive testings and shall review and approve all related results. All mechanical testings shall be carried out by a certified testing facility subject to prior approval of the COMPANY.

The Welding Engineer (WE)

The Welding Engineer of the fabricator shall be responsible for:

  • conducting the welding procedure tests in accordance with AWS D1.1/ASME SEC IX or any other standard as applicable;
  • conducting all applicable mechanical tests as per the applicable 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:

  • AWS D1.1                     – For structural work;
  • ASME SEC.IX             – For piping and pressure vessel work;
  • DnV-OF-OS-01           – For pipeline work;
  • API 1104                       – For pipeline work.

Welding of test joints

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

ISO 9001:2008 Requirements related to WPS/PQR Qualification

ISO 9001 clause 7.5.2 states as follows:

7.5.2 Validation of processes for production and service provision

The organization shall validate any processes for production and service provision where the resulting output cannot be verified by subsequent monitoring or measurement and, as a consequence, deficiencies become apparent only after the product is in use or the service has been delivered. Validation shall demonstrate the ability of these processes to achieve planned results.

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 carrying out 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

PQR – 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 (CA)/ 3rd party  – Customer appointed inspection agency for the project, such as ABS, BV, DnV, Lloyd’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 : Ability of a material 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

Specimen 

Fig 2 – Mechanical Test Specimen (Courtesy of www.lloydsregister.co.uk )

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, HIC & SOHIC Tests

Tests for weld quality

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

Codes, Standards and Customer Specifications/Requirements

For example, the following is a summary of 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 system an oil and gas project.

std codes - welding

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 a controlled tension until failure.

ISO 6892-1:2009 “Metallic materials — Tensile testing — Part 1: Method of test at room temperature” specifies the method for tensile testing of metallic materials and defines the mechanical properties which can be determined at room temperature. The test involves straining a test piece in tension, generally to fracture, for the purpose of determining one or more of the mechanical properties . The test is carried out at ambient temperature between 10oC and 35oC, unless otherwise specified. Tests carried out under controlled conditions shall be made at a temperature of 23 oC ± 5 oC

Pipeline and Piping System
—  Client Specs
—  Reference Code: API 1104:2005
—  Test Method: API 1104 20th Nov 2005
Structural
—  Client Specs
—  Reference Code: AWS D1.1

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. Following the bend, the sample is inspected for cracks on the outer surface. Bend testing provides insight into the modulus of elasticity and the bending strength or a material.
Pipeline and Piping System
—  Client Specs
—  Reference Code: API 1104:2005 add 2007
—  Test Method : API 1104:2005
Structural
—  Client Specs
—  Reference Code: AWS D1.1

Nick Break Test

Type of Test : Nick Break Test
Pipeline and Piping System
—  Client Specs
—  Reference Code: API 1104:2005 add 2007
—  Test Method : API 1104:2005
Structural
—  Client Specs
—  Reference Code: AWS D1.1

Charpy Impact Test (Weld Joint Section)
Type of Test: Charpy Impact Test (Weld Joint Section)
Description of Test:
ISO 148-1:2009 “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 1104:2005
Structural
—  Client Specs
—  Reference Code: AWS D1.1 : 2010
—  Test Method : ASTM E23-07a E1

Vickers Hardness Number (HV), Load test 5 Kgf & Macro Examination and Photo

Pipeline and Piping System
Type of Test: Vickers Hardness Number (HV), Load test 5 Kgf
Description of Test:
ISO 6507-1:2005 “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 aangle between opposite faces at the vertex is forced into the surface of a test piece followed by measurement of the diagonal length of the indentation left in the surface after removal of the test force, F.
—  Client Specs
—  Reference Code: API 1104:2005
—  Test Method : ASTM E384-2010 e2
Type of Test: Macro Examination and Photo
—  Client Specs
—  Reference Code: API 1104:2005
—  Test Method : ASTM E340-00 (Reapproved 2006)

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

Video: “TWI – an introduction to mechanical testing techniques”

URL: http://www.youtube.com/watch?v=0WMWUP5ZHSY
Published on Mar 7, 2012
Category : Science & Technology
License : Standard YouTube License
Video Description :
This video shows how materials respond to forces both quantitatively and qualitatively using a variety of different testing procedures.
To find out more , please visit: http://www.twitraining.com or http://www.twi.co.uk

Training Center :
There are many training providers in the field of welding in Indonesia, for example as follows:

PUSDIKLAT MIGAS (Education and Training Center on Oil and Gas) – CEPU
Jl. Sorogo No. 1, Cepu (http://www.pusdiklatmigas.com/)
Authorized Training Body (ATB) – PUSDIKLAT MIGAS CEPU  is a training institute and qualification of personnel in the field of welding. Provide and serve as Technology Services: welder certification, manufacture of WPS and PQR for oil and gas industry and other industries.

Laboratory of Mechanical Testing in Indonesia:

  • Balai Besar Bahan dan Barang Teknik (B4T)
    Jl. Sangkuriang No. 14, Bandung 40135
    Telp. +62 22 2504088,  +62 22 2504828, +62 22 2510682, Fax: +62 22 2502027, Website: http://www.b4t.go.id/
  • UPT Laboratorium Uji Konstruksi – BPPT ( UPT LUKBPPT ) – Jl. Raya Muncul. Kawasan Puspiptek Serpong 15314 – Tangerang, Banten
  • PT. Hi-Test (Jakarta) – Taman Tekno, Block A2 No. 49, Bumi Serpong Damai – Tangerang, Tel: +62 21 75881884 Fax: +62 21 75881885. Website: http://www.hitestlab.com/

Pictures:

Fig 1 – Introduction to Mechanical Testing (Courtesy of http://www.twitraining.com)
Fig 2 – Mechanical Test Specimen (Courtesy of www.lloydsregister.co.uk )

References / Read more / Related links :

Advertisements

4 responses to “An Introduction to Mechanical Testing for WPS / PQR Qualification

  1. Pingback: WELDING & WELDING INSPECTION | Mande Blog·

  2. Really aspect of content. I recently stumbled upon your website and in accession funds to claim i always find really treasured account your current web site blogposts. Regardless I will be checking for the rss feeds or perhaps I actually achievement people accessibility constantly fast on line fuel orders.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s