Thursday, September 2, 2010

Part One: Alignment, Measurement & Weld Measuring Gauges


this is one of the giant project that i got involved during my on job training...
The semi-submersible production system for Gumusut-Kakap field is being constructed by Malaysia Marine and Heavy Engineering’s (MMHE) fabrication yard in Pasir Gudang, Johor, Malaysia.
Development drilling commenced in January 2008 and the field will be using 19 subsea wells with oil exported via a pipeline to a new oil and gas terminal, which will be built in Kimanis, Sabah.

Welding Qualifications

Welding Qualifications

Welding Procedures, Welder Approvals and Welding Procedure Specifications explained.

European Standards
An introduction to European Welding Standards. (427Kb pdf File)
John Dyson
Basic Guide
A basic introduction to Welding qualifications and why they are required
Welding Procedure Specifications(WPS)
Welding Procedure Specifications to EN ISO 15609-1 (formerly EN288 Part 2). Why are they required and what should they include. 
ASME Section IX
Guidance on the qualification of welding procedures and the performance testing of welders to section 9 of the ASME boiler and pressure vessel code.  Approval Range Calculator.
European & ISO Welding Standards
These new standards are renumbered and updated versions of the old EN288 series. Information is also provided about the older standards.
NEW Approval Range Calculator.
Automatic/Machine Welding
Guidance on the qualification of welding operators to EN and ASME Rules
Independant Inspection Authority
Royal & SunAlliance is probably one of the most helpful Inspection agencies around.

Welding Procedure Specification:- Example

Welding Procedure Specification:- Example

Weld Procedure Number 30 P1 TIG 01 Issue A
Qualifying Welding Procedure (WPAR) WP T17/A
 Manufacturer: National Fabs Ltd
25 Lane End
 Location:  Workshop

 Welding Process: Manual TIG
 Joint Type: Single Sided Butt Weld
Method Of Preparation 
and Cleaning:
Machine and Degrease
Parent Metal Specification: Grade 304L Stainless Steel
Parent Metal Thickness  3 to 8mm Wall
Pipe Outside Diameter  25 to 100mm
Welding Position: All Positions 
Welding Progression: Upwards

Joint Design Welding Sequences

Run Process Size Of
Filler Metal
Type Of
Wire Feed
Heat Input
2 And Subs
70 - 90
80 - 140

 Welding Consumables:-
 Type, Designation Trade Name:
 Any Special Baking or Drying:  Gas Flux:
 Gas Flow Rate - Shield:
                         - Backing:
 Tungsten Electrode Type/ Size:
 Details of Back Gouging/Backing:
 Preheat Temperature:
 Interpass temperature:
 Post Weld Heat Treatment
 Time, temperature, method:
 Heating and Cooling Rates*:

 BS 2901 Part 2 : 308S92
 No  Argon 99.99% Purity
 8 - 12 LPM
 5 LPM
 2% Thoriated 2.4mm Dia
 Gas Backing
 5°C Min
 200°C Max
 Not Required
Production Sequence
1. Clean weld and 25mm borders to bright metal using approved solvent.
2. Position items to be welded ensuring good fit up and apply purge
3. Tack weld parts together using TIG, tacks to at least 5mm min length
4. Deposit root run using 1.2mm dia. wire.
5. Inspect root run internally
6. Complete weld using 1.6mm dia wire using stringer beads as required.
7. 100% Visual inspection of completed weld

Revision History
Date Issue Changes Authorization
26/11/2000 A First Issue Jack Straw    Jack Straw

Welding Procedure Specifications

Welding Procedure Specification Example
Welding Procedure Specification Example

 A WPS is a document that describes how welding is to be carried out in production.  They are recommended for all welding operations and many application codes and standards make them mandatory What information should they include?
 Sufficient details to enable any competent person to apply the information and produce a weld of acceptable quality.  The amount of detail and level of controls specified on a WPS is dependant on the application and criticality of the joint to be welded.
 For most applications the information required is generally similar to that recorded on a Procedure Qualification Record (PQR) or Welding Procedure Approval Record (WPAR), except that ranges are usually permitted on thicknesses, diameters, welding current, materials, joint types etc.
 If a WPS is used in conjunction with approved welding procedures then the ranges stated should be in accordance with the approval ranges permitted by the welding procedure.
 However careful consideration should be given to the ranges specified to ensure they are achievable, as the ranges given by welding procedure standards do not always represent good welding practice.  For example welding positions permitted by the welding procedure standard may not be achievable or practical for certain welding processes or consumables.
 EN ISO 15609-1 (formally EN 288 Part 2)  European Standard For Welding Procedure Specifications
EN ISO 15609 Defines the contents of a Welding Procedure Specification in the form of a list of information that should be recorded.  For some applications it may be necessary to supplement or reduce the list. For example only in the case of a procedure requiring heat input control would there be a necessity to quote travel speed or run-out length for manual processes.
 ASME IX  American Boiler and Pressure Vessel Code
QW 250 Lists the variables for each welding process, all the variables stated should be addressed.  The range permitted by the WPS is dictated by the PQR or PQR’s used to qualify it. 

Typical Items That Should Be Recorded On W.P.S:-
     Common to all Processes        .
  • Procedure number
  • Process type
  • Consumable Size, Type and full Codification.
  • Consumable Baking Requirement if applicable
  • Parent material grade and spec.
  • Thickness range.
  • Plate or Pipe, Diameter range
  • Welding Position
  • Joint Fit Up, Preparation, Cleaning, Dimensions etc.
  • Backing Strip, Back Gouging information. 
  • Pre-Heat (Min Temp and Method)
  • Interpass If Required (Maximum Temperature recorded )
  • Post Weld Heat Treatment. If Required (Time and Temp)
  • Welding Technique (weaving,max run width etc.)
  • Arc Energy Limits should be stated if impact tests are required or if the material being welded is sensitive to heat input.
Specific To Welding Processes MMA TIG MIG
Welding current  yes yes yes yes
Type of Welding current AC/DC   Polarity  yes yes yes yes
Arc voltage   If Auto yes yes
Pulse parameters (Pulse time and peak & backgound current)    If Used If Used  
Welding Speed If Mechanised   yes yes yes
Wire configuration        yes
Shielding gas (comp,flow rate)    yes yes  
Purge gas (comp & flow rate)    If Used If Used  
Tungsten electode Diameter and type.    yes    
Nozzle diameter    yes yes  
Type of Flux Codification & Brand Name        yes
Nozzle Stand Off Distance (Distance from tip of nozzle to workpiece).       yes
A sketch of the joint configuration is required which should include the basic dimensions of the weld preparation.  Some indication of the run sequence is also beneficial, particularly if the correct sequence is essential to ensure the properties of the weld are maintained. 
Production Sequence
Whilst this is good practice it is not a requirement of either ASME 9 or EN288 Part 2; it could be issued as a separate QA procedure if preferred.
Non Destructive Testing
A WPS is primarily concerned with welding not N D T, this activity should be covered by separate N D T procedures.

Thursday, August 19, 2010


Friends You have welcomed me into your place and allowed me to make it my home. I will always be grateful for that, which I cannot leave without saying goodbye. This blog has made me into what you think I am. I’ve seen the good in each of you. I’ve seen regular people like you all do extraordinary things. I’ve seen you help each other up after you’ve knocked down. I’ve seen you stand together when times are tough. And I’ve seen the smallest act make the biggest change. If I’ve done anything right, I hope its help you realize one person can make a difference in the lives of others - faith in yourself and you will find hope in each other.
                Remember, it’s not the mask that makes the hero. It’s the choices we make and the desire to do what’s right. I’ve seen that desire in all of you. It inspired me to do everything in my ability to protect our relationship. – But I can’t promise that I’ll around forever. One day, we will get to be in our own line, destiny and faith.
                But if that day comes, please, keep our friendship remain endless without me to make the world a better place. Be the heroes in friendship I know you are.