2. 1) Right of Way clearing and
grading
2) Delivery , Transporting ,
Handling , Hauling,
Stringing of pipes.
3) Trenching Normal & Rock
4) Bending
5) Lining up And Welding
6) Radiography Inspection
7) Application of Joint
Coating
8) Lowering & back filling
9) Tie-ins
10) River and Road crossings
11) Clean-up and restoration
of ROW
11) Air Pigging cleaning and
gauging
12) Hydrostatic testing
13) Dewatering cleaning and
swabbing
14) Golden Tie-ins
15) Valve Installation
16) Calliper Survey and dent
repairs
17) Line Preservation
18) Boundary Pillars
19) Kilometre Post
20) TP marker & Direction Marker
21) Documentation
Activities of Pipeline Construction
3. Right Of Way (ROW)
Activities
ROW opening document handling over to contractor.
18m marking of ROW Corridor.
Centre Line Marking based on Intermediate Points and
Terminate Points.
Wooden Pegs are put on either side of the centre line at a
distance of 9 meters for 18m ROW
6m marking for pipeline on the left of the ROW corridor and
12m
for movements of equipments
Cleaning and grading of the ROW strip from bushes , trees
etc.
4. Resources
ROW Document.
Wooden Pegs .
Survey Team and Survey Marker
Measuring Tape.
Powder to mark the line.
Dozer, Dozer Operator, Dozer Helper.
Some Unskilled labours.
Right Of Way (ROW)
5. Transportation Handling and Stringing of the
Pipes
Activities
Approaching to the site
Delivery Inspection
Loading Arrangement in trailor
Tying the pipeline with nylon strap at every three meter.
Profiled wooden support is prepared and pipeline is laid on it.
Rubber pads bevel protector is put on the ends of the bevels.
Unloading arrangement of pipe at the site.
Putting pipe at the sandbags to avoid any damages
Pipe is put in a string
6. Resources
Material Requisition
Nylon strap
Wooden support
Sandbags
Cranes , Crane operator, Crane helper
Tailor, Tailor Operator, Tailor helper
Technician, Rigger for loading, Supervisor
Some Unskilled labours
Transportation Handling and Stringing of
the Pipes
7. Trenching
Activities
Excavate the trench soil
Making extra depth to fit minimum radius of bend at
crossings.
Top soil of 30cm is store separately.
Making temporary crossings / diversions at bridges at road
crossings.
Resources
Backhoe as excavator.
Backhoe operator, helper, supervisor.
Foreman
2-4 unskilled labours to do random activities.
8. Bending
Activities
Pipe is inserted into the bending machine.
Pipe is bended in vertical or horizontal direction as mentioned
in alignment sheet.
Mandreal is inserted inside the pipe to prevent it from
buckling while bending.
Ovality of bent pipe is checked by passing a gauge disk of
95% of internal diameter.
Sag bends are dressed up so to put at bottom of trench to
avoid any damage.
Material is flown is checked at external point to check the
reduced thickness.
10. Welding
Activities
Pipe is line up for welding
Pipe is lined up through internal or external line up clamp
Pipe is put on wooden support.
Cleaning and grinding of bevel.
Welder Qualification Test is done to get qualified welders.
Welders specimen sample is tested on destructive test to
check the strength of sample.
In destructive test it is subjected to below test-
1) Tensile strength test
2) Nick Break Test
3) Root , face and side bent test
11. After welder is qualified , then it is approved on mainline
welding
Making availability of generator to operate welding activities.
Providing the welding accessories and equipment’s to
welders
Welding is done in four phases-
1) Root run for about 6-8 inches/min
2) Hot pass for about 11-13 inches/min
3) Filler-1 for about 9-11 inches/min
4) Filler-2 for about 3-5 inches/min
Above welding activities is done at 5g position, downhill(from
top to bottom)
Welding
12. Resources
Line-up clamp. For internal line-up clamp, compressor is
required
for compressed air.
Line-up clamp mechanic, helper
Side booms, operator, helper
Wooden support
Welding machine, welding accessories
Welding machine trailor, trailor helper.
Electrodes, Electrodes machine operator, helper, supervisor
Generator, operator , helper
Fitter, grinder, Foreman for supervision
Welding Inspector, Welding Engineer
Welding
13. Radiography
Activities
Transportation of X-ray source to the site , along with the
operator.
Making the area free from the any activity
Applying the film around the welded joints according to the
procedure, 10’O or 2’O lock.
Positioning of radioactive source, maybe inside or outside
Development of film.
Interpretation of radiographic images.
14. Resources
Licensed approved Radiographer, X-ray Machines, with
safety equipment’s.
Film source.
Barricading safety lead.
Image quality , film processing facility.
Interpretation developer , Interpreter
Computerized data entry facilities, computer system
Radiography
15. Joint Coating
Activities
Taking clearance from the radiography team.
If humidity is 75-85 % then heat the area before blasting
Cleaning the joint area.
Preheating of the welded joint area to 60°- 80° C.
Sand blasting the area to clean up the welded area.
Primer is applied on the welded area.
Sleeves is applied after primer coating.
Sleeves are overlapped at position of 2 or 10 ‘O’ clock.
Closure patch of sleeves is heated , pressed & sealed.
Roller is pressed to remove trapped air.
Holiday test is done to detect any pinholes in pipe.
Peel test is done on next day to check the strength of the
sleeves
16. Resources
Compressor , Flame machine
Primer Paint .
Primer paint Brush
Sleeves
Blasting equipment, 1 helper
Sand blasting unit
2 for sleeves, 1 for heat, 1 for rolling
Holiday tester, operator, helper.
Joint Coating
17. Lowering & Backfilling
Activities
Trench is cleared from all debris, stones, pipe cut pieces,
welding rods, etc.
Dewatering the trench
Repairing of the coating damages.
Sand padding to put pipe on gravel/pebbles in rocky areas.
Lifting the pipe with minimum 3 side booms to lower down in
the trench.
Lowering clearance from joint coating site is taken
Radiography clearance for left out joints is taken.
Coatings is checked visually and repaired.
Depth of trench is checked around of 1.5m
Width of trench is checked at bottom , to be of around 1.2 m
18. Night caps are put on open ends of pipe section.
Pipe is lifted with side booms by the sling, sling is avoided on
the welded area.
Pipe is lowered in the trench at a distance of 400 mm from
the HDPE Pipe.
Warning tape is put at 400mm above HDPE Pipe.
Resources
Side booms, operator,, helper
Foreman, rigger , insulator for repair
Dewatering pump.
Sand padding
Measuring tape.
Night caps
Warning tape.
Lowering & Backfilling
19. Tie-Ins
Activities
Marking the joints to be tied in which are left during mainline
welding.
Pipe is line up for welding
Pipe is lined up through internal or external line up clamp
Making availability of generator to operate welding activities.
Providing the welding accessories and equipment’s to
welders
Welding is done in four phases-
1) Root run for about 6-8 inches/min
2) Hot pass for about 11-13 inches/min
3) Filler-1 for about 9-11 inches/min
4) Filler-2 for about 3-5 inches/min
Above welding activities is done at 5g position, downhill(from
top to bottom)
20. Tie-ins
Resources
Line-up clamp. For internal line-up clamp, compressor is
required
for compressed air.
Line-up clamp mechanic, helper
Side booms, operator, helper
Welding machine, welding accessories
Welding machine trailor, trailor helper.
Electrodes, Electrodes machine operator, helper, supervisor
Generator, operator , helper
Fitter, grinder, Foreman for supervision
Welding Inspector, Welding Engineer
21. Crossings
Activities
Bore path is determined under the crossings.
Statutory authority permission is taken.
Equipment’s deployed .
Soil investigations is done.
For small crossings , open cut trench is made, after installing
pipe it is backfilled.
For submerged pipe , a concrete coating is done across the
pipe,
Pipe of thick wall thickness (0.375m) is installed.
For lengthy bore path, pipe is installed in casing
Casing of 6 inch extra diameter than carrier pipeline is used
.Cased crossing is executed by the horizontal boring technique.
Horizontal Direction Drilling machine & crew set up is done at
site.
22. Boring path is tracked and monitored by the HDD crew.
Hydrostat pre-testing is done at pressure corresponding to
95% SMYS.
Insulator is placed between casing and carrier pipeline to
provide isolation between them. 2 insulators is placed at the
end
Air vent is provided at the end of the casing to let the moisture
evaporates
Electrical test is done to determine the resistance between
carrier pipe and casing pipe or carrier pipe or soil.
Pipe is installed
100% radiography is done for the welded joints.
Closed sheet piles is laid if boring pits is unstable.
Backfilling in boring /exits pits is done at 15cm after checking
90% proctor density by mechanical compactor after
dewatering.
Crossings
24. Clean-up and Restoration
Activities
Cleaning the site , removing all the construction material.
Restoring the ROW corridor and taking the NOC from the
land owners.
Taking NOC from the statutory authority, government
authority.
Resources
Cranes, Dozer
Operator, helper
NOC document
25. Air pigging cleaning and Gauging
Activities
Pig is carried with loader at the launching site.
Pig is launched into the pipe with the help of launcher and
compressed air.
Gauge plate of 95% of ID is fastened to pig.
Pig location and signals is monitored by the pigging crew.
Pig is received at the other end through the receiver
Retrieved gauge plate is analyzed and preserved.
Brush Pigs , Foam pigs etc. are launched into pipe for
cleaning purposes
Resources
Pig , Pig carrying trailor , trailor helper
Pig launcher and Pig receiver , operator , helper
Gauge plates
Pig monitoring crew.
26. Hydrostatic test
Activities
Mechanical clearance is taken .
Water testing certificate and corrosion inhibtor is checked
Instrument and equipment’s is checked for valid calibration
Gauge plate of 95% ID and 10 mm thickness is passe
through the pig to check the dent.
Repairing of the dent, if not then pipe section is cut
accordingly.
Checking the condition of the hydrostatic header.
Welding the header through the qualified welder.
Water is taken from the tested source.
Water is filled 500mtrs before first pig and 1000 meter
between first and second pig.
After the pig is received then water flushing is done for 2 hrs.
27. Resources
High capacity filling pump
Pressurizing pump
Corrosion Inhibitor Injection Pump
Water free from debris
Pressure gauge of proper range
Dead bed tester
Pressure recorder with chart
Temp recorder with chart
Ambient temp recorder
Portable thermometer
Test header
Pigs
Additional- Vehicles, Tents , dewatering stations ,welders and
welding accessories
Hydrostatic test
28. Markers and Valve Installation
Activities
Marking boundary pillars at every 250 m
Marking with kilometre post
Marking turning point marker
Marking direction marker before and after a TP at 200m
Marking a warning sign
Valves location is marked and installed wherever is needed
Resources
Boundary pillars
Markers
Kilometre post
Valves
29. Activities
Dewatering by using foam pigs in pipeline
Cleaning by brush pigging
Magnetic Pigging to attracts electrodes and iron parts present
inside pipeline.
Pigging records is monitored
Download the data and record it for future use.
Resources
Dewatering pump
Pigs, Pig launcher , Pig receiver , operator, helper
Pig monitoring team/agency
Calliper Survey
30. Line Preservation
Activities
Preserving the line from the internal corrosion by the inhibited
water
If the time period is more than it is filled with nitrogen
Line is kept with air tight pressure.
Resources
Inhibited corrosion protector
Nitrogen. Pressure monitoring gauge
31. Documentation
Activities
Collecting all the data from all the construction activities and
teams
Getting the data approved from the clients.
Archiving the data for the future use.
Resources
Data from all the construction activities and teams.
