Welding procedure specification

Welding procedure specification

Producing a welding procedure involves:

 AWS D.1.1: Structural Steel Welding Code

 BS 2633: Class 1 welding of Steel Pipe Work

 API 1104: Welding of Pipelines

 BS 4515: Welding of Pipelines over 7 Bar

Other codes may not specifically deal with the requirement of a procedure but may contain information that may be used in writing

a weld procedure

 EN 1011Process of Arc Welding Steels

Welding Procedures

• Heat treatments/ storage

Components of a welding procedure

• Root gap, root face

• Jigging and tacking

• Type of baking

 Welding Position

• Location, shop or site

• Welding position e.g 1G, 2G, 3G etc

• Any weather precaution

 When the data has been collected, the procedure must

be validated by producing a test weld, weld procedure

test (WPT).

 A number of standards provides information with

regards to approving a procedure, but normally this will require the WPT to be tested by NDT and mechanical testing.

 The locations and tests required will be given in the

applicable code or standard

 Most codes and standards provide a report format to

record the results

Approving the procedure:

After the testing is completed and all the relevant results

collated, the results need to be assessed in accordance with the relevant code/standard The results are then generally recorded

 pWPS: Preliminary Welding Procedure Specification pWPS:

Before procedure approval

 WPS: Welding Procedure Specification:

After procedure approval

 WPAR (WPQR): Welding Procedure Approval Record WPAR (WPQR):

Welding procedure test record

Once the welding procedure has been approved, If any

essential variable is changed during production the WPS may

require re-approval Most codes/procedures dealing with

procedure qualifications provide a list of what is an essential

or non-essential variable.

Object of a welding procedure test

To give maximum confidence that the welds mechanical and metallurgical properties meet the requirements of the

applicable code/specification

Each welding procedure will show a range to which the

procedure is approved (extent of approval)

If a customer queries the approval evidence can be supplied

to prove its validity

Once the content of the procedure is approved the next

stage is to approve the welders to the approved procedure A

welders test know as a Welders Qualification Test (WQT)

Object of a welding qualification test

To give maximum confidence that the welder meets the

requirements of the approved procedure (WPS)

The test weld should be carried out on the same material and same conditions as for the site welds

The welder who carries out the procedure qualification weld automatically qualify when the procedure qualifies

1 Welders name and identification number

2 Date of test and expiry date of certificate

3 Standard/code e.g BS EN 287

4 Test piece details

5 Welding process, welding parameters, amps, volts

6 Welding parameters, amps, volts

7 Consumables, flux type and filler classification details

8 Sketch of run sequence, welding positions

9 Joint configuration details

10 Material type qualified, pipe diameter etc

11 Test results, remarks

12 Test location and witnessed by

13 Extent (range) of approval

BS EN 287

The inspection of a welders qualification test.

 It is normal for a qualified inspectors usually from an

independent body to witness the welding

 Under normal circumstances only one test weld per welder

is permitted

 If the welder fails the test weld and the failure is not the fault

of the welder e.g faulty welding equipment then a re-test

would be permitted

 The testing of the test weld is done in accordance with the applicable code, but it is not normal to carry out test that test for the mechanical properties of welds e.g tensile, charpy

and hardness tests

QU 2 What do you understand by the term extent of approval and

give four examples.

QU 3 Describe what you understand by a welding procedure

specification, A welding procedure approval record and a welder certificate

QU 4 What is the reason for approving a welding procedure and

a welder

QU 5 Give three reasons why a welder may require

re-qualification.