The purpose of this method statement / pipe welding procedure is to define and outline proposals for carrying out the welding & installation of MS piping System.
Method is applicable to all ERW, Black Steel, Schedule 40, Grade ‘B’ and fittings, in accordance with mechanical specifications for pipe sizes 65mm dia. and above.
The work will be done in accordance with approved Shop Drawings and approved material submittal for pipes, fittings, valves, supports, pumps and accessories.
Other reference documents include but not limited to:
- Contract Specifications
- Project Quality Plan
- Consultant and contractor project Health and Safety plan.
Definitions & Abbreviations
HSE: Health Safety and Environment
ITP: Inspection and Testing Plan
ITR: Inspection and Testing Request
MAR: Material Approved Request
MIR: Material Inspection Request
Roles and Responsibilities
Project Manager shall be responsible for the overall project start execution and completion.
Project Manager will be based on site and will be responsible for the management of the project, both on and off site, through delegation of duties in accordance with the organization chart and for the effective implementation of the project management system.
He shall ensure that the proper tools and tackles are available for the timely completion of this job in a quality manner.
MEP Coordinator is responsible for co-ordination of all MEP services to ensure that they do not clash with one another during installation.
He is also responsible to check and ensure that MEP services are coordinated with Structural / Architectural finishes including false ceiling.
MEP coordinator is also responsible to check and ensure that MEP services provisions are provided in the shop drawings to all other trades as per the scope & requirements of the project.
He is responsible to liaise with Consultant and Main Contractors to achieve proper coordination of MEP services and ensure all Coordination Drawings are submitted & approved to meet the approved construction and submission program.
HSE Officer will monitor and implement all HSE related issues.
He shall ensure that all necessary requirements regarding health, safety and environment concerns are met and adhered to.
HSE officer will coordinate with HSE officers to ensure that all permits and authorization are on hand prior to starting any site operation.
QA/QC Manager/Engineer/Inspector
Quality team shall ensure that the MS pipe welding work is carried out ensuring that the requirement for quality control is followed.
He shall ensure that all ITP requirements are met.
The QA/QC engineer/manager shall ensure that all necessary requests for inspection and testing are processed and put forward to the consultant for notification.
He shall ensure all inspections conducted as per contract specifications , QCP (Quality control procedures) & ITP’s to ensure all inspections proper tools & tackles and manpower are used at all stages of work to ensure all current issues of procedures, approved materials and shop drawings and standards are available at the point of use.
QA/QC shall be responsible for the total quality of work for the installation work.
He will do inspection for any damage during shipping, handling and storage. Monitor the quality of works and ensure that fulfillment of specified requirement and that all quality records related to work are completed. Ensure the work is completed as per quality requirement.
Main contractor QA/QC shall inspect the same work prior to initiating ITR for consultant approval.
Quality engineer/inspector shall maintain comprehensive inspection and test record for documentation.
Project Mechanical Engineer shall ensure that all the pipe welding works are carried out according to the approved shop drawings.
Direct and supervise all personnel including site engineers and supervisors, taking into considerations as per all relevant documents.
He shall review the method statement before starting the work, explain the same to the subordinates and prepares program for the daily job.
He shall be aware of all code of practices, standards and specifications and HSE plan and to appreciate the work force to perform a time bound and quality job.
Originate ITR for complete installation works and accompanies QA/QC engineer/inspector during inspections from consultant/client.
Site Engineer shall ensure that all works are carried out according to approved shop drawings, approved material submittal and approved method statement.
Ensure all safety equipment proper tools, tackles and PPE are available at the point of use.
Aware of all procedures, work method, instruction, quality requirements for the timely completion of the job and explains to the task to workers for execution of the job with applicable code of practice.
Tools & Equipment’s for Welding Work
Below is list of necessary tools and equipment performing the welding and pipe installation activities.
Fork Lift or Crane with suitable capacity
Hydraulic Trolley
Portable Drilling Machine/Grinding Machine & Angle Cutter 
Pipe Fitters Tools Boxes
Spirit Level & Level threads
Step Ladder as per site requirement
Scaffolding with platform as per site requirement
Welding machine, Oxy – Acetylene Gas cutting set,
Chain Block pulley and Shackles
Pulley and rope
Grooving Machine
Pipe cutter, Grinder, Angle cutting machine and webbing sling
Pipe Welding Procedure
Before commencement of any welding the following works are required to be carried out.
- Check materials to be used have approved material submittals.
- Check work areas are clean and safe ensuring that the area is free of all flammable or volatile material.
- All welding work shall be carried out in open or ventilated areas.
- Welder’s qualification will be verified as per requirement.
Welding Procedure
Measure length of pipe required, making due all allowance for any pipe fittings to be used.
Cut the pipe to the measured length and ensure that the ends are cut square.
Prepare the end of the pipe to be welded to the right angle of level and the size of the root face in accordance with procedure specification.
The surfaces to be welded shall be smooth, uniform and free from tears, scale, slag, grease, paint and other materials that might affect the quality of welding.
Power tools or hand tools will be used for cleaning, grinding or both.
The two prepared ends to be welded, pipe to pipe or pipe to fitting, shall be aligned as accurately as is practical and ensuring that the spacing between the abutting ends is in accordance with the procedure specification used.
Alignment of the abutting ends shall minimize any offset between the surfaces caused by dimensional variations and will equally distribute around the circumference of the pipe any such offset.
Hammering of the pipe to obtain proper lineup will be kept to a minimum.
The two prepared ends shall be tack welded together in four positions at ninety degrees.
After tacking, the alignment shall be checked to confirm the integrity of the alignment has been preserved.
During the welding process the tacks shall be removed by grinding.
The welding process will commence, ensuring that the correct filler metal, electrical current, polarity, voltage, amperage and number of passes is in accordance with the welding procedure.
All slag or foreign matter shall be removed from each pass of welding, including the repair of any visible defects, such as crack, cavities, etc., prior to commencing the succeeding passes.
Any such impurities shall be removed using a grinder.
On completion of the welding process the welders designated identification mark will be placed adjacent to the weld.
This weld will also be given a unique joint number as indicated on the welding drawings.
Weld joint shall be visually inspected to check for inadequate penetration, excessive undercutting, burn-through, and to ensure the weld is free from cracks.
The weld shall not be cooled by water.
Weld Inspection & Testing
100% visual inspection will be carried out for all welded joints.
All weld joints will be subject to hydrostatic testing to a minimum of 1.5 times the operating pressure.
Inspection requests will be raised for Consultants visual inspection and witness testing.
Sample welding test will be organized for all welders.
HSE Requirements for Welding Process
Proper tool box talk shall be given to the personnel involved in carrying out the welding process.
The method statement shall be communicated to the crew during the tool box talk.
Mandatory PPE i.e. safety shoes, helmet, hand gloves, overalls, goggles and other appropriate PPE for the task shall be used.
Safety items to be provided shall include fire extinguishers and welding screens.
Welding cables to be checked regularly for visual signs of damage, any joints to be sheathed and taped.
Prior to commencement of work check welding machine i.e. current, voltage, earthling, etc., for safety.
Standard welding Safety kit of shields, gloves, etc. to be provided for each welder.
Glasses to be checked for cracks / weld spatter
Permit to Hot work (PTW) should be obtained prior to commencement of welding work.
Project Engineer / Safety officer shall ensure that all safety precautions are taken as per the project HSE plan.
Ensure that chain block, shackles & webbing slings are calibrated with valid certificates and in a good working condition
Attachments:
- Inspection Test Plan for welding procedures.
- Risk Assessment for MS Pipe welding.
- Inspection check list