METHOD STATEMENT FOR PIPE SUPPORT FABRICATION & INSTALLATION

1. PURPOSE 

This method statement is to establish the work plan and inspection instruction for the assembly, fabrication, inspection and documentation to be performed in order to complete the construction of pipe hangers and supports which shall be in compliance with applicable drawings and specifications.

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2. SCOPE 

This method statement covers all pipe hangers, spring, cold shoe, clamped, supports and embedded plate to be assembled, fabricated, installed and inspected Project.

3. REFERENCE 

• Basis for Piping Engineering  
• Piping Material Specification  
• Piping Standard Drawing 
• Piping Support Standard Drawing 
• Specification for Piping Work 
• Specification for Piping Fabrication by Each Service Class 
• Specification for Painting 
• Welder Qualification Procedure 
• Material Control Procedure 
• NDE Control Procedure 
• Method Statement for Painting 
• Method Statement for PWHT 
• ASME B31.1 Power Piping  
• ASME B31.3 Process Piping 
• ASME Sec, IX Qualification Standard for Welding and Brazing 
• ASME Sec. V Nondestructive Examination 
• ASME Sec. II Welding Rods, Electrodes and Filler Metals  

NOTE: In case of conflict between this method statement and reference documents, followed below. 

As a standard practice, method statement will follow the specification and then, specification will follow the code. 

In case the specification has conflict with method statement.  It would be decided after discussions at the meeting. 

4. ORGANIZATION AND RESPONSIBILITIES 

The Construction Manager has the responsibility to: 

• Plan the fabrication program and report it’s progress 
• Manage all fabrication drawings. 
• Preparation, revision and control of this document. 
• Managing of raw materials. 
• Managing of welding consumables. 
• Inspect the fabrication and installation of support and changes of it’s design. 
• Ensuring that design changes are incorporated into the work. 
• Requesting NDE or PWHT, if any 
• Requesting inspection to the QA/QC Team. 
• Preparation of material requisition of material for support fabrication work. 
• Control of welder and support welding data   
• Requesting and preparation for welder and welding operator qualification. 

The QA/QC Manager has the responsibility to : 

• Review of all request including Daily Welding Inspection Report. 
• Managing welder qualification. 
• Managing welding control system. 
• Managing of quality control. 
• Managing inspection and test with regard to support fabrication and installation. 

The Material Control Manager has the responsibility to: 

• Receiving and maintaining of material 
• Control of material stock status before release to construction team. 
• Issuance of material to Support shop and other sections. 
• Request the material receiving inspection to QA/QC team 

5. GENERAL  

Material to be installed will be withdrawn from the receiving area in accordance with material control procedure, the prefabricated sub assembly storage area, or the lay down area. Transferring the material from the storage area to work site will be performed in a manner which will not be deleterious to the material. 
When storage requirements are not defined, the type of storage and protection shall be determined through arrangements with project owner.  

5.1. General Work Sequence 

• Make production plan considering material availability and area priority. 
• Issuance of Isometric drawing or support style list to support fabrication shop. 
• Request support material to material warehouse 
• Receiving support material from warehouse and perform receiving inspection. 
• Issue work order 
• Cutting and end preparation 
• Fit-up and tack welding 
• Welding 
• Inspection 
• Blasting and primer painting work at paint shop 
• QC documentation 
• Release support and store on stock yard (13) Support issuance to Field support team.  

5.2. Storage and handling material 

• Material shall be stored separately by its type and specification and it shall be marked according to its designated color. 
• Certificates verifying that materials or items used in the fabrication comply with Purchaser’s requirement.  Certificates for each category of material shall be submitted. 
• Materials shall be maintained to comply with any warranty conditions imposed by the manufacturer. 
• Nylon slings shall be used for handling stainless steel material and straps. 

5.3. Drawing and materials 

• Pipe support shall be fabricated and installed in accordance with the approved drawing, pipes support style list. 
• For pipes requiring post weld heat treatment, attachments required for supporting purposes shall be indicated on the piping isometric drawings. 
• Pipe stanchions, pipe dummies and trunnions shall be made with same type of material as the connecting pipe.  All other support material to be welded directly to the pipe shall be same type of material as the pipe itself. 

5.4. Inspection and test 

The inspection and test shall be notified to QA/QC team 24hours in advance prior to inspection and testing, and it shall be performed in accordance with the inspection and test plan. 

6. WORK PROCEDURE 

6.1. Control of pipe supports fabrication 

6.1.1. Raw material 

All material of pressure retaining parts shall be identified. 

Part number, material specification and heat number shall be marked on the piece to be cut, and it shall be recorded on the material identification record, and it shall be inspected by QC inspector before cutting. 

6.1.2. Cutting 

Support materials may be cut to shape and size by flame or thermal cutting. 

Stainless steel materials shall be cut by mechanical means or plasma arc cutting, but flame cutting shall not be allowed.  Surface to be welded shall be free from slag and excessive notch foreign matter. 

Pipe support assemblies may be acceptable if items having greater strength are substituted for those indicated on the drawings. 

6.1.3. Welding 

Welding shall be performed in accordance with the approved WPS and drawing by qualified welder. 

These fabricated support shall be inspected and recorded using the ‘Daily Fabrication Inspection Report’ (Attachment 1). 

Field welding to pipes for the purpose of pipe support shall be limited as far as practical. Field welding for pipe support purposes shall not be performed on the following pipe materials. 

• Materials requiring post weld heat treatment (PWHT) 
• Non-ferrous materials 

All welding shall be done before post weld heat treatment 

Stainless material shall be segregated from normal carbon steel during fabrication and erection in order to avoid the contamination.  

6.1.4. Marking and Tagging 

When welding has been completed, designate person will tag on each support body with stamped tags. 

The characters on such tags shall be a minimum of 3/16 inch and tags shall be securely attached to the assembly. 

6.1.5. Painting and Stock 

When fabrication of pipe support is done, prepare the painting request form and transport to painting area. (Attachment 5) 

 Painting subcontractor shall paint and submit painting inspection report to contractor. Painted pipe support should be marked and properly identified and shall be stored in the designated area and preserved from dust and rust until issue to field erection. (Attachment 4) 

6.2. Control of Pipe supports installation 

6.2.1. General 

As a general practice, appropriate adjustment / modification / addition of support shall be made by construction contractor according to the actual field conditions, especially for small bore piping. 

All pipe support must be installed as per specification and drawing. 

• Isometric drawing 
• Piping arrangement drawing 
• Pipe support standard drawing 
• Special pipe support drawing 
• Pipe support index 

Piping shall be properly anchored and guided before pressure testing. 

Support should be fabricated and installed prior to the piping installation, and use of temporary supports is to be minimized. 

In case the temporary supports are required, the supports arrangement shall be made sure so that they have sufficient bearing strength and stable supporting for the piping system. 

All temporary supports shall be removed before hydro test. 

Field welded supports shall be set correctly in place and adjusted to the final position before welding. 

For sliding supports, bearing surfaces shall be sufficiently clean to ensure unrestricted movement. 

Clamp bolts on clamped shoe type support should be checked as per standard pipe support drawing. 

Support shall not be welded to the equipment unless otherwise specified. 

In case that stainless steel piping without insulation is resting on the steel structure, pipe rack or piping support directory, stainless steel plate shall be installed between piping and structure to avoid direct contact, even if this information is not shown in support drawing. 

6.2.2. Concrete expansion anchor bolts 

Installation of concrete expansion anchor bolt shall be performed in accordance with vendor information. 

6.2.3. Locking devices (Bolts / Nuts) 

The support height shall be adjusted by construction team to the actual field condition. All threaded connections, except high strength bolts, shall be secured by locking devices to prevent loosening during service. 
Wherever possible bolts/stud shall be locked in place with double nut. (Jam nut) A nut tack welded to the bolt/stud shaft may also serve as a locking device and may be used except where welding is prohibited on the bolt material. 

6.2.4. Installation of Spring hangers 

Installation of constant and variable spring hangers shall be in accordance with the manufacturer’s instruction, the design drawing and the procedure. 

Spring hangers shall be easily accessible after installation within the limits of possible, and the scales shall be unobstructed and visible. 

Field engineer should be ensured that the travel stops are engaged and maintained thus on all spring hangers until the piping system are placed in service, except during such time of checking and marking adjustments on the spring hangers. 

Spring supports shall be installed with the spring locks in place and the travel shall be cold set position. 

These spring locking plates or pins shall not be removed until hydro static testing and insulation of the piping system has been completed, but before the line is put into service, as directed by commissioning group. 

If the spring force on empty line will cause possible damage to connected strain sensitive equipment, the spring locks shall remain in position until the line is filled with the actual service fluid. 

The relevant support and support drawing shall bear the warning “block against empty position” and the locks shall be attached with the spring support during operation. The travel stops on spring hangers shall be engaged during filling, testing and draining of pipe systems for hydro test. 

6.2.5. Floor of base mounted supports 

Grouting is required between concrete surface and structural pipe support attachment plates. 
All grout work shall be performed in accordance with relevant work procedure. 
Non shrink grout shall be mixed and placed in according with the manufacturer’s written instruction. 

6.2.6. Wall or ceiling mounted supports 

Pipe support base plates shall be mounted flat against the wall or ceiling. 

Irregularities on the wall or ceiling surface that prevent flush mounting on the base plate, such as fins, protrusions, and excessive roughness, shall be removed by grinding. Grouting is not required except when depression, grooves, holes or other cavities under the base plate that are not amenable to removal by grinding. 

These shall be filled with grout before mounting the base plate. 

6.2.7. Hanger rod and turn buckle installation 

Threading of hanger rods shall be performed in accordance with ASME B31.3 para 321.1.5, thread designation UNC and, shall have a minimum of three full thread exposed when the nut is tightened on the hanger rod threads. 

Lubricant for threaded portion of rod is not required. 

For galvanized threads cut in the fields, the threaded portion of the rod shall have a touch-up coating. 

To compensate for pipe elevation discrepancies, hangers are usually provided with means to permit vertical adjustment during and after installation 

Threaded devices such as turnbuckles, clevises, etc. are acceptable, provided that after the adjustment the result is no less than full thread engagement. 

6.2.8. Shoe or pads installation 

For shoes shall be welded to the piping with careful way avoiding any welding defects. 

Special care must be taken to the anchor points, as they are to be heavily loaded. 

Shoes pads for low alloy steel piping shall be of the same material as the pipes. In case of lines having shoe or saddle support, site measurement between distances of supports may be given and marked on the assembly. 

The supports are then welded on the spool assembly on the ground. 

In case of lines having guide or anchor the supports are to be welded in position. All supports / saddle welded to main pipe shall undergo the same testing requirement as that of main pipe. 

For the installation of Embedded plate shall be followed in accordance to Concrete Works Procedure.

6.3. Welding and welding attachment 

• All welding shall be in accordance with approved welding procedure specification. 
• The material of the attachment which is directly welded to the pipe shall be as shown on the pipe support detailed drawings. 
• Welding must be carried out by qualified welder in accordance with approved welding procedure specification. 
• Material traceability report shall be recorded the heat-number of attachment and verified by QA/QC inspector and Contractor’s inspector for stainless steel and alloy steel. (Attachment 2) 
• Daily welding inspection report shall be signed off by QC inspector after visual inspection. 
• All weld attachment on pipe shall be identified by marking the weld and welder number. 
• All welds will be identified on the isometric drawing and shall be inspected by welding inspector and recorded in daily welding inspection report. (Attachment 3) 

6.4. Post Weld Heat Treatment (PWHT) 

• Performance of PWHT shall be in accordance with post weld heat treatment procedure. 
• The QA/QC shall review PWHT record and submit to owner for review. 

6.5. Non Destructive Examination (NDE) 

• The management and request of NDE shall be in accordance with NDE control procedure. 
• The QA/QC shall review NDE record and submit to owner for review. 

6.6. Paint and Touch up painting 

• At completion of fabrication and installation, painting subcontractor shall paint or touch up paint the pipe support according to painting specification and procedure. 
• Pipe construction manager is responsible for keeping and maintaining all related documents. 

6.7. Progress check 

• Progress of fabrication and installation in pipe support shall be measured together with piping progress using progress measuring program. 
• Every support item shall be tracked by this system. 

7. HEALTH SAFETY ENVIRONMENT AND SECURITY 

All workers shall wear PPE required as below. 

• Safety helmet 
• Safety glasses 
• Safety shoes 
• Gloves 
• Mask, if required to prevent inhalation of dust and welding gas 
• Ear plug, if required by conditions. 

Machinery like grinding wheel cutter shall have a protection method. 
Safety shall be requested and carried out in accordance with safety procedure.  

8. ATTACHMENTS 

• Attachment 1:  Daily Fabrication Inspection Report                             (DFIR) 
• Attachment 2:  Material Traceability Record                                        (MTR) 
• Attachment 3:  Daily Welding Inspection Report                                  (DWIR) 
• Attachment 4:  Inspection Report for Embedded Plate Fabrication     (IREPF) 
• Attachment 5:  Release Note for Field Installation                               (RNF) 
• Attachment 6:  Release Note for Painting                                             (RNP) 
• Attachment 7:  Job Safety Analysis                                                       (JSA)  

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GENERAL METHOD STATEMENT FOR FOUNDATIONS

 

1. PURPOSE

The purpose of this general method statement is to describe the construction procedures for the isolated pile cap and pad foundations. Large raft foundations will be covered in specific foundation method statements and are not included in this document.

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2. SCOPE

The works will incorporate the procedures necessary to execute the following items:

Preparing of Work, Survey& Setting Out, Excavation, Dewatering, Pile (If Applicable), Blinding Concrete, Foundation — Rebar- Formwork — Concrete, Embedded Items, Back fill, Pedestal

3. DEFINITIONS

Client = ABC
Contractor = SBC Responsible in the supervision of the sub-contractor who will perform the construction work and all related activities as outlined in this procedure
Sub-Contractor = XYZ Responsible in the execution of the construction work as well as the tests required in accordance to this procedure

4. RESPONSIBILITIES

4.1. Construction Manager and Senior Engineer 

Construction Manager and Senior Engineer responsible in ensuring the implement of construction procedure and method statement, the Quality Control of work, Supervise the work and reporting the progress of work to Site Manager.

4.2. Safety / Environmental Officer 

Safety / Environmental Officer responsible in ensuring that all activities are carried out safety patrol at the site, Establishing the site safety plan, conducting continuous safety inspection and stop any work deemed unsafe and a risk to personal, taking action to rectified the unsafe condition and report to project manager and preparing the notes of safety meeting.

4.3. QA / QC Engineer 

QA / QC Engineer responsible to monitor the execution and performance of the works in relation to this method statement, approved drawings and material specifications; detect and report non-conformance; ensure that all non conformance products or activities identified are reported; propose the corrective and preventive action where possible and appropriate and record the completion the Non Conformance.

4.4. Site Engineer & Foreman 

Site Engineer & Foreman responsible in all activities on site are carried out in accordance with the schedule and the construction drawing and take care all worker to be work with their responsibilities and make a decision when some non-conformance occurring their report to senior engineer

5. SAFETY

Refer to the site safety policy for general safety controls. One of the main aspects of this procedure is Safety and Health Control. This is to control occurrence of injuries as well as damage to equipment and properties during the entire construction period. In order to ensure a safe working environment during the entire construction period, the following safety measures will be implemented:

5.1. Machinery and Equipment:

• Prior to using any machineries /equipment at site, it shall be inspected and certified by qualified person.
• Periodic Preventive Maintenance shall be made on all equipment and machineries.
• All operators and drivers are to be equipped with valid driver's/operator's license or permit from concerned government agency.
• Only authorized drivers or operators will be allowed to operate machineries or equipment.
• Only authorized signalman shall be assigned together with the operator or driver.
• All lifting equipment as well as its accessories such as sling wire, nylon sling, shackles, chain blocks crane hook and latch shall be inspected periodically.

5.2. Personal Protective Equipment:

• Personal Protective Equipment (PPE) shall be issued to all workers such as safety shoes, hardhat, working gloves, earplug, safety goggles (if required) and safety belt and or safety harness for workers who will be assigned in elevated places 2.0meter and above.
• Wearing of the basic PPE shall be enforced fully.

5.3. Safety Arrangement during the Foundation Work:

• Emergency Action Plan 

Note: All new recruits shall undergo proper orientation and safety induction before they are deployed at site for work.

6. WORK PROCEDURE

6.1. Preparation of Works:

• Foundation works will not commence until confirmation that all pre-construction planning and safety checks are completed.
• The supervisor shall be familiar with the latest construction drawings and method statements.
• Plant and equipment requirements will be assessed on a case-by-case basis for each foundation location and agreed with the Construction Manager prior to starting the works.

6.2. Survey and Setting out

Before work starts survey department will establish baselines and benchmarks from which co-ordinates and elevations will be taken to set out the foundation works.

6.3. Excavation

• Excavations will generally be executed in open cut to the size, slope and elevation shown on the construction drawings and/or design calculations.
• Survey will set out and check edge slope and bottom founding level of excavation.
• Excavation will be carried out with excavator and the excavated material loaded directly into dump truck and transported to temporary stockpile area.
• A small bucket or manual digging will be used when excavating between piles. 
• The final bottom founding level under each foundation will be inspected by QC and tamped or compacted as per design requirements before pouring blinding concrete. 
• For a description of all related work activities refer to MS0501 -General method statement for open-cut excavations.

6.4. Dewatering

• From the site soil report the relative groundwater level is approx. -2.5m below existing ground level
• During excavation and after reaching the required excavation level a dewatering system will be installed as required and any water discharged to the vicinity drainage
• For a description of all related work activities refer to General method statement for dewatering excavations.

6.5. Piles where applicable

• Following final excavation the piles will be cut down to design pile cut off level.
• Removed sections will be lifted out and taken to designated disposal area.
• After cleaning, the pile head Treatment will be done to connect pile to foundation.
• For a description of all related work activities refer to Method statement for pile cut-off.

6.6. Blinding Concrete

• Bottom of the excavation should be dry and tamped or compacted to a uniform level before pouring the 50 mm thick lean concrete blinding layer.
• For a description of all related work activities refer to General method statement for concrete.

6.7. Foundation

After QC inspection of the prepared founding level and lean concrete base layer then construction of the foundation will follow.

6.7.1 Rebar

• Rebars will be cut and bent on site in line with the agreed construction sequence. 
• Installation of rebar will begin as soon as blinding concrete has hardened enough for trafficking (normally 12 hours)
• A mobile truck crane and/or manual workers will be used for rebar installation.
• Rebar placement sequence will follow the latest rebar construction shop drawings. 
• Suitable concrete spacers will be used to achieve the desired covers and additional rebar spacers will be installed to maintain support of top steel and any cast-in items. 
• All pedestal column starter bars and cast-in anchor bolts will be accurately located and securely fixed in the correct position.
• Location, spacing, verticality and cover shall be checked during the installation process and QC will make a final inspection prior to calling up concrete.
• For a full description of all work activities refer to General Method Statement for Rebar.

6.7.2 Formwork

• The form work system to be adopted for each foundation type and size will be as specified in approved calculations prepared by the Temporary Works Design Engineer. The different types of form work for site installation purposes are summarized in Table Appendix 
• Plywood sheathing with timber and steel props will be used for form work and manual labor will be used for lifting and placing according to survey-lines of the foundation outline.
• Approved form release agent is applied prior to lifting-in and erection of the clean forms.
• Forms are connected tightly together and braced to the excavation profile or waling in the case of a sheet pile wall.
• For a full description of all work activities refer to General Method Statement for Form work.

6.7.3 Concrete

• 1 no concrete pump will be available (with back-up pump) for placing concrete at a rate of around 35-40m3/hr. In some cases, pouring concrete will be done by bucket and 25T mobile crane at a rate of 1 0-15hr.
• A minimum of 4 nos of 50mm vibrators shall be used for compaction.
• Unless agreed otherwise the foundations will be poured at one time in layers, starting from the center and spreading out to each side. CHECK IF CORRECT!
• Keep concrete alive without performing any cold joints.
• Manual tools and float are used to finish the top surface.
• For a full description of all work activities refer to General Method Statement for Concrete.

6.8. Embedded Items

• All embedded items and cast-in anchor bolts shall be placed to the specified installation tolerances shown on the construction drawings.
• Special care will be taken to place and maintain embedded materials to the proper setting location to prevent movement during the progress of the work and to tamp concrete thoroughly around them.
• For a full description of all work activities refer to General Method Statement for embedded items.

6.9. Repair and Touch-up.

After striking of forms a QC inspection will be conducted to decide whether any repairs to the concrete surfaces are necessary.

For a full description of concrete repair procedures and materials to be used refer to General Method Statement for Concrete repair and touch-up.

6.10. Back filling

• Backfilling operations will be executed in two (2) stages using suitable excavated sand material.
• The first stage fill will be placed up to the top of foundation level and will commence as soon as formwork has been removed and QC inspection of foundation is approved.

NOTE: - If this method is adopted then curing f foundation will be done using ??????? curing compound.................................................................................................................................................................................................................................................................................................................................................................................................................................

• Backfilling will be done in loose layers not more than 250mm in thickness.
• Suitable vibrator plate/rollers and/or water will be used to achieve the compaction requirements for each layer field density test will be performed to check the soil compaction to 95% maximum dry density.
• Any embedded cable way conduits and earthing/grounding wires, drainage pipes and trenches etc. should be installed simultaneously with the backfilling laye 18.
• After completion of the concrete pedestal then the second stage fill will be carried out up to grade level below proposed finished ground level
• For a full description of all work activities refer to General Method Statement for backfilling of excavations.

6.11.  Pedestal

• Pedestal columns vary in height between??? ????? and 
• Heights exceeding ????????? will be cast in two (2) lifts.
• Formwork will be made using plywood form panels in sizes to suit manual installation and dismantling.
• All construction joints will be properly prepared at location indicated on the construction shop drawings.
• For general construction details and work procedures refer to General Method Statements for Rebar, formwork and concrete.

7. TOLERANCES

As final design drawings and/or Main Contractors instructions.

8. REFERENCES

• Specification: Client's Technical Specification for Civil Works, Section 6 — Material and Workmanships Sub-section 6.4 "Concrete Work".
• Safety provisions: Refer to Site Safety Plan.
• Related Method Statements:
• General Method Statement of Concrete General Method Statement of Reinforcement General Method Statement of Formwork General Method Statement of Concrete Repair and Touch up   Drawings: Refer to latest "For Construction" drawing list.

9. APPENDICES

• Appendix A: Activity Organization Chart
• Appendix B: Emergency Action Plan
• Appendix C: 1. Foundation Location Plan
• Foundation Schedule
• Foundation Construction Sequences

10. EXHIBITS

Title: Foundations

Appendix A: Activity Organization Chart.

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METHOD STATEMENT FOR NATURAL GAS PIPELINE INSTALLATION

1.     INTRODUCTION

This Method statement describes in detail the Installation of Natural Gas Pipeline. This includes addressing programs for implementing commitments regarding the quality of Natural Gas Pipeline works.

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2.     OBJECTIVE

This method of statement shall be used as a guideline to assist ABC personnel to fully understand their responsibility on how to execute their work in a safely and efficient manner throughout the project.

3.     WORK SCOPE

This procedure is applicable to all Natural Gas pipeline installation at Zubair and aims to:

To ensure that all works carried out comply in all respect with the Act and Regulations and by laws of the followings:

• Client Standard
• Code of Practice for the Installation of Fuel Gas Piping Systems and Appliances
• Occupational Safety and Health Act and Regulation 1994

Not limited to the above act and regulations, the duty to comply extended to any other authority having jurisdiction over the scope of works.

4.     WORK ACTIVITIES

• Storage management
• HDD work
• Soil excavation work
• Soil backfill work
• MDPE pipe and fittings installation
• Carbon steel pipe and fittings installation
• Anti-corrosion tape wrapping work
• Coring work
• Sleeve insertion works
• Gas cock installation
• Leakage testing
• Housekeeping

5.     WORK PREPARATION

5.1.    Pre-job meeting

Pre-job meeting shall be held prior to the commencement of any work activities at site in order to ensure all parties involved are well informed of the work process and the associated safety hazards. Toolbox talk and JSA shall be held with the workers prior to commencing work.

5.2.     Manpower

ABC shall be represented by: -
Engineering Manager – He is responsible of all activities related to the project. He is available on request or as per job requirement.
Project Manager – He is responsible of the execution of the project. He is available full time at site.
Project Executive – He assists Project Manager in the execution of the project. He is available on request or as per job requirement.
Site Supervisor – He is responsible of the manpower planning onsite. He is responsible to obtain all permits required prior to the job, holds toolbox talk and JSA with workers and ensures work complies with the design. He is also responsible for chairing daily progress meeting onsite. He shall act as the immediate authorized person in the absence of the Project Manager.
Welder – He is responsible of MDPE pipes and fittings fusion, carbon steel sch40 pipe and fittings welding and conducts leakage testing.
Fitter – He is responsible for general works at site.

• Management                         : 3 person
• General Workers                 : 7 person
• Total no. of workers at site : 8 person

5.3.     Machinery, Tool & Equipment

ABC shall provide good working equipments in order to complete the work safely. ABC shall supply but not limited to the following equipment’s: -

• Electro-Fusion Welding Machine
• Pipe Clamp
• Diesel Generator
• Welding Set
• Thread Machine
• Drilling Machine
• Speed Cutter
• Rotary Hammer
• Grinder
• Hacker
• Coring Machine

5.4.     PPE & Safety Equipment

ABC shall supply sufficient & comply with the mandatory requirements of standard PPE i.e.

• Safety helmet
• Safety shoes
• Safety glasses
• First aid box

1.     JOB EXECUTION

6.1.    Storage management

ABC shall erect site storage facilities to store all work materials, tools and equipments. The store shall act as ABC site office.

6.2.   Horizontal Directional Drilling (HDD) work

To carry out Horizontal Directional Drilling (HDD) work for underground MDPE pipe installation across the main road.

1. Prior to carrying out HDD works, ABC shall discuss and verify with the main contractor and consultant the area/path to be drilled. Drilling path designed with consideration to the position of existing utilities, accessibility of drilling rig and geographical site, and shall be at least 3 feet below the road. Details of utilities shall be marked on plan, should necessary final adjustment will be made at site.
2. Radio detection shall be used to finalize the path. Trial hole shall be excavated to verify the base of the underground utilities. Warning signs and colored bunting shall be erected at locations of overhead power cables. Work area shall be barricaded with warning signs erected.
3. Horizontal distance and cross sectional profile of the proposed bore shall be determined with measuring tape and dumpy level. Drilling path shall be marked on the ground.
4. High viscosity drilling fluid shall be used to prevent the collapse of borehole during drilling. Drilling fluid viscosity shall be monitored and maintained at Funnel Viscosity 40 secs/quart.
5. A (1.5 m x 1.0 m) x 1.0 m depth pit shall be dug at the entry& exit point to cater for cuttings &fluids.
6. Commence drilling operations by attaching a 3” diameter fluid jet drill head with sensor to the drill rod. Drilling trajectory shall be monitored at every 3m by Digitrak Electronic tracking system.
7. Locator technician shall inform drilling operator should drill head strays off course. Adjustment shall be made by the drilling operator.
8. At exit pit, drill head shall be removed and replaced with a fluid jet reamer.
9. Reamer shall be retracted through the drilled hole – at doing so borehole will be enlarged and more cuttings will be removed. Different diameter reamers shall be used to enlarge borehole in steps to a max of approx. 30 percent than pipe size.
10. MDPE pipe will be laid on rollers after being string up.
11. After final reaming, pipe will be attached to the last reamer & swivel & will be pulled into borehole.
12. Upon installation pipe ends shall be capped to prevent foreign particles ingress. Site shall be cleaned and reinstated and drilling rig demobilized.

6.3.     Soil excavation work

To conduct soil excavation work to lay underground MDPE pipe and underground carbon steel pipe (c/w anti-corrosion tape).

1. Prior to carrying out excavation works, LWG shall discuss and verify with the main contractor and consultant the area/path to excavate.
2. Permit shall be applied and made available at site. Toolbox talk shall be held prior to starting work.
3. JCB excavator shall be mobilized, unauthorized personnel kept out of the excavation area.
4. Trench shall be excavated as per approved drawing. It shall be prepared as such that the pipe lays on a firm, continuous bearing on the bottom.
5. Excavator demobilized and site cleaned in preparation for pipe laying.

6.4.            MDPE pipes and fittings installation

1. Welders shall make sure that all pipes and fittings are dry, free from burrs, suspended matter & oil.
2. Prior to joint the pipe with electro-fusion machine, MDPE pipe shall be aligned properly by clamp.
3. For more detailed information on electro-fusion joint of MDPE pipes and fittings, refer to attachment B.

6.5.            Carbon steel pipes and fittings installation

6.5.1.      Pipe Cutting

Pipes shall be cut to desired length based on shop drawing: -

1. Pipe length shall be measured by measuring tape and marked at the desired length based on endorsed shop drawing.
2. Speed cutter (on Portable Cut-Off Saw) shall be set on clean, dry, stable surface, without the presence of flammable elements and connected to the power supply.
3. Wear proper apparel. Do not wear loose clothings, gloves, necklaces, rings, bracelets or other jewelries’ which may get caught in moving parts. Nonslip footwear is recommended. Wear protective hair covering to contain long hair.
4. Safety glasses shall be used. Face or dust mask shall also be used.
5. Pipe shall be laid on the speed cutter, pipe marked position adjusted to speed cutter cutting wheel.
6. Pipe position shall be fixed at 90 degree with the base of speed cutter and hold down by clamps.
7. Before using the tool on pipe, let it run for a while. Watch for vibration or wobbling that could indicate poor installation or a poorly balanced wheel.
8. Switch on, wait until wheel attains full speed and lower gently cut the pipe on marked position.
9. Watch out for flying sparks when operating. They can cause injury or ignite combustible materials.
10. Do not overreach. Keep proper footing and balance at all times.
11. Do not touch the workplace immediately after operation; it is extremely hot.
12. Never leave tool running unattended.
13. Turn power off.
14. Do not leave tool until it has come to a complete stop.
15. Power off and disconnect power supply.

6.5.2.      Anti-corrosion Tape Wrapping

All underground, floor/wall embedded carbon steel pipes should be wrapping with anti-corrosion tape to keep the pipes corrosion free.

1. The pipe surface shall be free of mud, oil, grease or any others foreign material that will prevent the joint coating system from bonding to the steel pipe surface.
2. Visible oil and grease shall be removed with suitable solvent.
3. The steel surface shall be dry prior to the application of the joint wrap tapes.
4. KEROSENE shall NOT be used for cleaning the pipe joints.
5. Wrapping shall be applied under hand tension or using a hand-wrapping machine capable of maintaining even, constant tension across the width of the tape.
6. The wrapping shall be 55% over lap.

6.5.3.      Screw Thread Making

To fabricate male screw end on pipe, pipe shall be threaded by threading machine:-

1. The threading machine shall be set on clean, dry, stable surface, without the presence of flammable elements and connected to power supply.
2. Wear proper apparel. Do not wear loose clothings, gloves, necklaces, rings, bracelets or other jewelries which may get caught in moving parts. Nonslip footwear is recommended. Wear protective hair covering to contain long hair.
3. Be sure switch is OFF before plugging in. Carrying tools with your finger on the switch or plugging in tools that have the switch ON invites accidents.
4. Do not overreach. Keep proper footing and balance at all times. Proper footing and balance enables better control of the tool in unexpected situation.
5. Insert the pipe into the Threading Machine so that the cutting mark is located about 12 inches to the front of the speed chuck jaws.
6. Insert work pieces less than 2 feet long from the front of the machine. Insert longer pipes through either end so that the longer section extends out beyond the rear of the Threading Machine.
7. To avoid equipment tip-over, position the pipe supports under work piece.
8. Tighten the rear centering devise around the pipe by using a counter clockwise rotation of the hand wheel at the rear of the Threading Machine. This prevents movement of the pipe that can result in poor thread quality.
9. Secure the pipe by using repeated & forceful counterclockwise spins of the speed chuck hand wheel at the front of the Threading Machine. This action “hammers” the jaws tightly around the pipe.

6.5.4.      SMAW Welding

Shielded Metal Arc Welding (SMAW) or stick welding is a process which melts and joins metals by heating them with an arc between a coated metal electrode and the carbon steel pipe:-

1. Wear welding mask /welding goggle and welding glove.
2. Arrange cables to one side and away from the operator.
3. Do not coil or drape cables around body.
4. Keep welding power source and cables as far away from operator as practical.
5. Connect work clamp to pipe as close to the weld as possible.
6. Bevel the pipe end into 30 Degree by using grinding tools. And also remove oxidation and mill scale.
7. Align the pipe/fitting in jointing position with 1.5mm gap between 2 elements.
8. Set-up the welding machine with proper amp and select an electrode.
9. Electrode angle should be 75° - 80° according to welding position.
10. The electrode outer coating, i.e. flux, assists in creating the arc and provides the shielding gas and slag covering to protect the weld from contamination.
11. The electrode core provides most of the weld filler metal.
12. Weld the joint by moving electrode along the pipe end bevel at the correct speed, the metal deposits in a uniform layer will seal the joint (bead).

6.5.5.      Leakage testing

Pneumatic leakage testing shall be conducted by welder prior soil backfilling for MDPE pipe and cement patching for embedded carbon steel pipe.

1. Testing pressure is determined by 1.5x of operating pressure or minimum 5 psig.
2. Testing shall be witnessed by main contractor / consultant.
3. Testing record must be documented and endorsed by main contractor / consultant.

6.5.6.      Temporary Bracket Installation

Nail bracket shall be applied to all embedded carbon steel pipes for temporary positioning before cement plastering: -

• Fabricated pipes shall be aligned into pipe groove.
• 2 pieces of nail (approx 3mm Ø x 25mm length) shall be derived into the wall/slab and nail head secured with slim wire to hold pipe in centre.
• Care to be taken not to scratch/damage pipe.

6.6.     Coring works

To core floor slab / beam by Coring machine to allow pipeline to be installed through.

• Prior to carrying out coring works, LWG shall discuss and verify Coring position and obtain permit from main contractor and consultant.
• Mark core position and fit/mount the Coring machine in position by using wall plug.
• LWG shall equip the Coring machine with proper size of core bit and provide current supply.
• Switch on the Coring machine and spray water on the core hole during process.
• Turn off coring machine after bit core is through the slab/beam.
• Dismantle the wall plug and clean the coring site.

6.7.     Sleeve insertion works

• Tools and equipment’s to be prepare e.g. measuring tape, PVC pipe etc.
• The level of PVC to be inserted at the wall slab shall be measured and marked.
• PVC pipe shall be cut using pipe cutter and pipe’s butt sealed with masking tape.
• The completed PVC pipe shall be inserted into the floor beam mold.
• Tighten the PVC pipe with the wire at the mesh wire.

6.8.     Soil backfill work

To conduct soil backfilling work after the installation of underground MDPE pipe & underground carbon steel pipe.

1. Upon installation, the underground piping shall be covered with sand bedding.
2. Tracer wire, warning slab, protection slab shall be laid to mark the position/as protection to the installed piping system.
3. On top of the protective concrete slabs, the trench shall be filled and compacted with soil. Drawings as per Attachment A.
4. GI. B pipe sleeve is required as a protective sleeve for road-crossing pipes.

6.9.    Gas cock installation

Gas cock shall be installed at each gas outlet after the pipeline system installation is complete.

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