Quality aspects in Cross Country Pipeline construction

Knowledge acquired on for example -
• Failure of construction practices
• Concrete coating instead of concrete block on Pipeline
• Care for CP current draining from PT / TT stubs
• Improvements in CP system
We developed & implemented many procedures and
improved quality aspects thereon
Whether our learnings adequately followed or now days we
are noticing some issues in recently laid pipelines
Where we stand in quality
We learnt lot about cross country pipeline from Mumbai Manmad
Pipeline

Cost avoidance for project
Add Prevention
and reduced
failures / Re-
work through
effective
implementation
of a QMS
How Much Quality Costs

Comprehensive Quality assurance plan (QAP)
Develop procedure & approval for each every activity of Pipeline ( Nearly
40 procedures)
Formats for records
Inspection test plan (ITP)
Third party inspection
Operation team inspection
Sl. No. Activities
Inspection Frequency Documents to
be submitted
by contractor
Remarks
BY Contractor BY PMC BY Client
How to ensure Quality

1. Alignment of Pipeline & precautions
2. Soil erosion in hilly areas & precaution in ROU grading
3. How pipelines get laid at lower cover & precautions in trenching
4. Where line pipe string is important and control needed
5. How to control failure of welding joints
6. What affects in field coating joint
7. Pipeline lowering & stress on pipeline – Best laid Pipeline experience
8. How backfilling makes difference in Pipeline corrosion
9. How pipeline get exposed on river banks & precaution in river crossing
10. Safety aspects in Pipeline construction
11. Why casing & carrier pipe gets shorted
12. How to make river bank protection
13. Where cathodic protection fails
Quality aspects in Pipeline construction

• Minimum length : Directly proportional to cost
• Minimum Forest : No National park
• Less habitation : avoid populated areas, city limits, built up areas having
human activities, passing through stone quarries
• Easy approach - ease of construction / Operation & maintenance
• Minimum Water bodies : minimum river width, avoidance of perennially
marshy and water logged area
• River crossing locations : River bed /Stable banks / Curve of banks
• Minimum electrical interference.
Critical aspects in Alignment finalization:

Pipeline life 25 – 30 years – any failure before 25 years is failure of Design /
Construction & Operational system
Pipeline hazard : Large risk , beyond boundary
Environmental Impact
Statutory compliances
Increase in maintenance cost
Operational loss
Why quality utmost important in Pipeline

The Environment (Protection ) Act -1986
Water ( Prevention & Control of Pollution) Act 1974
Air ( Prevention & Control of Pollution) Act 1981
The Petroleum and Mineral Pipelines (Acquisition of Right of
Users in Land) Act, 1962
The Petroleum Act’1934.
Petroleum Rule ‘2002 and its subsequent Amendment (if any).
The Explosive Act, 1884.
Manufacture ,Storage & import of Hazardous chemical Rules-
1989
Statutory compliances in Pipeline

National Highway Act, 1956
NOC for Water bodies (Canal / Rivers) , roads crossing
Railway Act , 1989
The Factories Act 1948
Labour Laws
Building & Other Construction Worker’s Act’1996.
Petroleum and Natural Gas Regulatory Board (PNGRB) Act’2006.
CEA Regulation 2010
Statutory compliances in Pipeline

ASME B 31.4 Pipeline Transportation Systems for Liquids and
Slurries
OISD-STD-141 Design, Construction And Inspection requirements
for Cross Country Liquid Hydrocarbon Pipelines
PNGRB Regulation Technical Standards and Specifications including
Safety Standards for Petroleum and Petroleum
Products Pipelines Regulations, 2016
API1104 Welding of Pipeline and related facilities
API 5L Specification of Line Pipe
Key Codes & Standards in Pipelines

Once alignment is finalized ROU is acquired under
The Petroleum and Mineral Pipelines (Acquisition of Right of Users in Land)
Act, 1962
And then construction activities start
Significant Step ROU acquisition

Construction practices cause of corrosion : internal corrosion or external
corrosion
Wash out in hilly terrains & river banks
Exposure of Pipelines due to less cover
Major reasons of construction related P/L failures

The most difficult problem occurs in open cut river crossings
Exposure of pipelines in river after 10 -15 years or after major floods
For example
Washout at
Masaru / Machhu River of VBPL
Chalakudi River of CCKPL
And there many more of OMC which we come to know during CHT
meets
Failures in open cut river crossings

Type of river bed
Scour depth
Flow path
Pipeline laying depth
Bank protection
Important factors in river crossing

Length river crossing : a critical aspect

Example of River crossing alignment

Standard river crossing using two sag bends
2.5 m Below
Scour

Standard river crossing using single sag bend

ROW boundary staking : Care to be taken survey number as
per section -6.
Specially where survey stone are missing and bending points
are not identified properly. Normally all bending points will
have a reference drawing.
Practical issue faced : after ROU grading all farm field gets open
for movement and it allows cattle to enter in farm and
damaging fields. So wherever necessary temporary fencing
needed on either side of ROW.
No sharp points or low points, ROW condition suitable for
rubber-tyred equipment traffic, till completion of work
ROU Grading

Natural or artificial deposits of loose soil, sand, heaps of earth, or
other fill materials, to be removed till stable natural ground level
Right-of-Use clearing and grading on the hillside : Cross Slope fall
shall be less than 10 %. Critical in to be seen in forest areas where
width of ROU is also less.
Drill, blast or excavate any rock or other material which cannot be
graded off with ordinary grading equipment in order to make an
adequate working space along the pipeline
ROU Grading

In the areas where groups of trees, groves, horticultural spreads,
gardens, grass-fields carry out the works in such a way that
damages resulting from the pipeline construction is kept to a
minimum by grading only the width of the Right-of-Way
necessary for digging the pipeline trench
Record of the existing water channels , water pipes across the
ROW , in presence of the competent authorities
In rough or steep terrain, grade access roads and temporary
bypass roads, if required.
No temporary or permanent deposit should block water
streams, make alternate arrangement if it is blocked.
Public travel shall not be inconvenience or wholly obstruction at
any point
ROU Grading

Minimum cover Pipeline cover + 500 for soft soil / 700 for hard rock
Trenching

Segregate top 300 mm of arable soil, to be replaced in original position after
the backfilling
The depth of cover -
Top of pipe to the top of the undisturbed surface of soil or the top of graded
strip, whichever is lower.
For river/watercourses that are prone to scour and / or erosion, lowest bed
profile after scouring / erosion. When scour level is not known, an additional
cover of at least 1 m ( over and above the cover mentioned) except in case of
rocky river bed;
Trenching

Whenever the specified cover cannot be provided due to site constraints,
additional protection in form of casings, bridging, etc to be provided and
noted in pipe book
When insisted by authorities, the depth shall be maintained as per the
direction of concerned authorities.
Proper /extra depth to fit the bends & space for tie-in welding
Manual excavation near pipeline crosses other underground OMC
Pipelines / utilities/structures,
The trench grading to provide a firm, uniform and continuous support for
the pipe
Trenching

If proper care not taken near river / nalla
When things go wrong; plug too small to
retain the river which flowed down the
trench
At time this causes big problem when
part pipeline is lowered
So adequate distance /height of trench
opening at river /
Nalla
Trench flooding

Carry out
trenching
before Pipe
stringing and
welding to
avoid damage
to pipeline
Trenching after welding

How pipelines get laid at lower cover & precautions in trenching

Trailers having proper wooden saddle with
soft padding
Crane lifting hook also should have soft
padding
Non-metallic/non abrasive belts with
minimum of 60mm width to be used for
lifting the pipes
Protect pipes end bevels with bevel
guard/protectors
Avoid intermediate storage of pipes
Suitable chains strip covered with rubber
padding shall be used to tie the pipes
securely to each bolster
Stringing

Side-boom or swinging crane or other suitable equipments, using suitable
lifting devices viz. Lifting hooks of sufficient width and depth, belts to
avoid damage to the coating and the bevel of pipes ends
No dragging and sliding of pipes
Sand bag free from stones
Pipes shall not be strung on ROW in rocky areas, until and unless blasting
activity has been completed area cleared of all debris
Inspection pipes for damage and defective pipes repaired/ rejected before
stringing
String pipes as per alignment sheets to ensure that pipes of the correct wall
thickness
Stringing

Establish number and degree of bends to accurate
Minimum bend radius not below 30 D
Procedure for bending : step length and maximum degree per pull per
feet of pipe
Check bending machine to bend pipes without wrinkles, buckle,
stretching and without damage to the coating
Over bends - the center of the bend clears the high points of the trench
bottom.
Sag bends - fit the bottom of the trench
Side bends - leave specific clearance to the outside wall of the trench
Bending of Pipes

The end of the bend not be closer than 1.5 m from the end of a pipe or
within one meter of a girth weld.
Change in ovalization not more than 2.5 %
Passing gauge plate consisting of two discs separated firmly by 300 mm
with a diameter equal to 95% of the nominal internal diameter
Defects or disbonding of the coating and holiday detector for cracks
No mitre bends permitted
Reduce the no. Of cold field bends to lay the pipe to conform to the
general contour of the ground and maintain a normal cover
Bending of Pipes

Welding pre –qualification records
Welding consumable rods & welding parameter as PQR
Welding process : SMAW – root & hot pass
Bevel inspected for damage/improper machining
Repair of dents of depth up to 1mm by grinding and
Depth 1mm~3mm by rebevelling and
Beyond 3mm shall be removed by cutting and rebevelling and cut bevel
UT and 100% DPT/MT to a length of 25mm from the cut end to ensure
flaw free base me
Welding

Internal clamp locked , second pipe held with side boom or crane
Maintain root gap checked accurately as per wps. Internal clamp is
mandatory and not to be released before 100% completion of the root
pass.
Long seams staggered in the top 90 deg
Minimize offset, not exceeding 1.6 mm for pipes of same wall thickness
For different thicknesses, a special transition piece to be used with a taper
of minimum 1:4
Min. Length of pup piece 1M and not more then three joints in a 10M
length of pipeline.
At the end of days work night cap shall be provided at other ends of the
string
Welding

Skid stability
Pre heating at least 100 degree centigrade prior to the commencement
of root run and subsequent runs. Three time of weld joint or 50 mm on
both side of pipes
Check preheating using calibrated digital pyrometer or temperature
indicating crayons
The root gap : measure accurately
Two welder starting – 1st at from 12 to 6 O’clock & overlapping at 6 and
2nd welder from 9 to 6 and 12 to 9 O’clock with overlapping at 12 & 9
Welding

Internal clamp is mandatory and not to be released before 100%
completion of the root pass.
Cleaning , hot pass in same sequence , fill pass.
No arc strike outside the bevel surface permitted.
No interruption in welding during a pass and complete as early as
possible.
Time lapse between root and hot pass shall be 4 mts. max. (mandatory)
and for Hot pass to subsequent pass 5mts max or as per approved WPS.
welder’s performance review
Proper return earth
Welding

Speed of welding travel / direction of welding
Every pass shall be cleaned by power brush/grinding machine and chisel
Capping max. 1.6 mm over the surface of the pipe
Different wall thickness examined both by UT and RT
Test 0.1% of the total number of welds completed for destructive testing
Welding

No new welder carry out welding without valid approval and id card
Wind shield made of metallic frame covered by G.I sheets/ tarpaulin
Visual inspection for
• Excessive reinforcement concavity of welds,
• Shrinkage,
• Cracks undercuts,
• Weld surface porosity
• Other surface defects.
100 % joint radiographed
.
Welding

Incomplete penetration (IP) or lack of penetration (LOP) : one of
the most objectionable weld discontinuities, allows a natural stress riser
from which a crack may propagate
Dark area with well-defined, straight
edges that follows the land or root
face down the center of the
weldment
Welding Defects

Internal concavity or suck back :weld metal has contracted as it
cools and has been drawn up into the root of the weld
Similar to a lack of penetration
but the line has irregular edges
and it is often quite wide in the
center of the weld image
Welding Defects

Internal or root undercut : erosion of the base metal next to the
root of the weld
Dark irregular line offset
from the centerline of the
weldment
Welding Defects

External or crown undercut : erosion of the base metal next to the
crown of the weld
A dark irregular line along
the outside edge of the
weld area.
Welding Defects

Offset or mismatch : welded together are not properly aligned
A noticeable difference in
density between the two
pieces
Welding defects

Inadequate weld reinforcement :thickness of weld metal
deposited is less than the thickness of the base material
Image density in the area of
suspected inadequacy will
be higher (darker) than the
image density of the
surrounding base material
Welding defects

Excess weld reinforcement :weld metal added in excess
of that specified
Radiograph is a localized,
Welding Defects

Cracks . cracks will appear as jagged and often very faint
irregular lines.
Detected in a radiograph only
when they are propagating in
a direction that produces a
change in thickness that is
parallel to the x-ray beam
Welding Defects

Cold lap : weld filler metal does not properly fuse with the base metal
Arc does not melt the base metal
sufficiently and causes the slightly
molten puddle to flow into the
base material without bonding
Welding Defects

Slag inclusions are nonmetallic solid material entrapped in weld
metal or between weld and base metal
Dark, jagged asymmetrical
shapes within the weld or along
the weld joint areas
Welding Defects

Porosity : result of gas entrapment in the solidifying metal
Appears as dark round or irregular
spots or specks appearing
singularly
Welding Defects

Cluster porosity :caused when flux coated electrodes are
contaminated with moisture. The moisture turns into a gas when heated
and becomes trapped in the weld during the welding process
Just like regular porosity but
the indications will be grouped
close together.
Welding Defects

Daily review of weld failure clause
Record number of welding joint failure on daily basis and analysis
Individual welder performance review
Type of welding failures
Feedback to welders
Training on prevention methods
Controlling welding defects

Qualified insulators : identity cards
Materials quality, not older than period of validity at the time of
application
Coating clearance is available from radiography crew
Cleaning of joint area and adjacent coating upto 100 mm, remove
weld spatter, flux and scale with suitable solvent
Surface preparation : uncoated steel surface sand blasted cleaned
to a finish equivalent to sa 2.1/2
Field joint coating

Roughness check with presso film of 50 - 70 microns profile
Ends of existing pipe protective coating chamfer at an angle of
300
Preheat the welded joint area to 60 -80 ℃ to remove the
moisture and check with checked by pyrometer
Apply solvent free the epoxy primer
Field joint coating

Sleeve installation to commence before drying of epoxy
Minimum overlap on the factory applied coating of 50 mm on both
sides after shrinking
Minimum 100mm overlap between the sleeve and closure patch,
closure patch positioned to one side of the pipe in 2’ o clock or 10’ o
clock position.
No air entrap and good bonding, specially around weld bead
Field joint coating

No cold spots or dimples on the sleeve surface
In case of unacceptable installation, the sleeve shall be removed and
replaced
Visual inspection : no sign of punctures, dents or air entrapment
Weld bead profile can be seen through the sleeve
Mastic extrusion on either of the sleeve
Holiday detection :a DC voltage of 25KV , calibrated every time
before commencement of inspection
Field joint coating

Peel test on one of every 50 joint coating or one joint coating out
of every day’s production which ever is stringent : ensure defined
resistance to peel , no bare metal visible and essentially free of
voids. Peel test portion to be repaired and repair ensured.
If peel test does not meet the requirement then, adjacent two
sleeves to be tested. If either or both the sleeves do not meet the
requirements the field coating shall be stopped
The thickness of field joint coating materials an average thickness
of 2.0 mm. The minimum permissible thickness at the apex of weld
seam shall be 1.6mm.
Field joint coating testing & repair

Generally defects repair on field joint coating are not permitted.
Defects/repairs, if any, detected during the holiday testing / peel
testing / visual testing to be repaired limited to one location per
field joint coating
When defects / repairs is more than one locations detected during
the field testing the entire coating to be rejected and fresh coating
to be done
Field joint coating testing & repair

Activity should maximum quality concern area for owner
Lowering shall done only after obtaining approval of pipe book of section
to be lowered. Control duration gap in welding and lowering.
Entire trench bottom checked for any rigid materials which could lead to
perforation / tearing of the coating remove all cuts, pipe supports, stones,
roots, debris, stakes, rock projections
Where water is present, no laying shall be permitted until the ditch has
been drained to the extent and for the time necessary to make visual
inspection possible of the bed on which the pipe is to be laid
Pre- check depth of trench as per requirement
Sand / soft soil padding at all places where rock, gravel, murrum or hard
soil is encountered up to 200 mm
Pipeline lowering

Lowering to follow as soon as possible, after the completion of joint
coating of the pipeline
Check by full circle holiday detector (25 kv dc ) , specially ensure working
of holiday detector in rocky area by proper grounding of pipe section
Damages, denting or other defects to be completely repaired before
lowering
The pipeline to be lifted and laid using side booms minimum. 3 nos.
Belts of non-abrasive material having adequate width for the fragility of
the coating
Pipeline lowering

Care while removing the belts from around the coated pipe, after it has
been lowered into the trench
damage caused to the coatings to be promptly repaired
No belt around field joint coating while lifting /lowering
avoid stresses and temporary deformations
The pipe section to be placed on the trench bed without jerking,
falling, impact or other similar stresses
Raising of the pipeline from the support does not exceed the values for
the minimum allowable radius of elastic curvature so as to keep
stresses on steel & coating with safe limits
Pipeline lowering

Pipe is laid gently by using sufficient number of side booms for holding
line in gentle S-curve maintaining the minimum elastic bend radius
Wherever the pipeline is laid under tension, as a result of undue stresses
at specific points, the trench to be rectified prior to lowering of pipe
Lowering shall not be left in half way.
prevent the movement of the pipe in the trench
The co-ordinates of the lowered pipeline at each turning point shall be
recorded using DGPS of adequate carousal + 1m. The top of pipe level
and final graded ground profile shall also be recorded.
Post padding work shall start immediately after lowering.
Pipeline lowering

The pipe is lifted by minimum three side boom acting in unison and
spaced so that the weight of unsupported pipe will not cause buckling
or damage
Belts or sling of sufficient width to avoid pressure damage to pipe
coating
The pipe is placed over the ditch so that it will not scrape the sides and
possible damage the coating on the way down
Pipeline lowering

Trench cleaning and padding
Check trench preparation
Side position and gap is
appropriate
Cradle for lowering /lifting
pipes
S curve
Pipeline lowering : an example

Best kind of lowering belt
Abrasion resistant Nylon coating
Alloy steel end irons and Rams
Horn fittings for greater
strength and less weight.
Belts in sizes above 12″ up to
60″ wide
Lifting capacity 33,100 kg
Pipeline lowering belt

Is any thing wrong in this :
Check the Pipe lifting
Gap in side boom lifting
Stress getting developed
Above ground pipe distance
from trench
Space to move , side boom
Pipeline lowering : undesired example

Whether trench preparation is
adequate
Whether trench is cleaned
Pipe lifting equipment
No of lifting equipment
What about S curve
Stress development
Lifting Rope / belt in backhoe

Whether support is okay in pipeline
lowered in trench
What happens with this kind of
support.

What improvement you would like

Pipeline lowering : Hilly area
Slope breakers
Sand bags : Filled
with sand and
cement in ration of
1:10
Water breaker

Pipeline lowering : Slope breaker

Tie- Ins
The potion of pipelines alignment which are left out during mainline
welding due to bends, crossings etc are connected in the form of tie-in
joints

Tie- Ins
Trench sufficient sized to facilitate for alignment welding and provide
adequate clearance to the welders to make sound weld
Tie-in fit at average ambient temperature to avoid variation in fit up
gap due to contraction / expansion
Use external clamp in such way that joint free from any excessive stress
and tension
After welding of one end, free end pipe cut, bevel and UT to check free of
lamination, 100 ٪DP/MPI tested.
Difference of wall thickness is not more than 1.6 mm then 1:4 taper by
internal grinding
External line up clamp released only after 60٪ of root welding
100% tested by ultrasonic & Radiography

Pipeline crossing Above the existing pipeline

Below the existing pipelinePipeline crossing

Crossing angle of pipeline as close as to 90° but not less than 30 °
Boring pit and receiving pit shall be prepared
Ensure that pit does not collapse
Temporary fencing warning sign
A soil investigation and determine the ground water table
Leveling pit and installation boring machine, alignment
Check out of roundness of casing pipe and that no dents
Insertion of casing pipe and augur boring carried out simultaneously
Cased crossing

Levels shall be checked at both end of the casing pipe to confirm the
slopes
Diameter of the hole bored shall be as close as practicable to the outer
dia of the casing pipe
Ground water table over the length of boring shall be lowered up to at
least 0.5 meters below bottom of pipeline
Cased crossing

The casing pipe and boring shall be extended a minimum of 0.6 m on either
side of crossings
Soil cut by the boring heads shall be inspected from time to time and in
case, the soil strata change the entire length of boring augurs shall be
retrieved and the boring head shall be replaced with the suitable one.
Casing pipes weld in the pit itself after insertion of the first pipe
OFC laid in HDPE pipe put in a separate carbon steel-casing pipe by
separate boring
Cased crossing

Insertion of carrier pipe
Carrier string weld joint hydro tested for a minimum period of 4 hours
before joint coating , weld joint checked for leakage
After pre-testing, joint coating done
Holiday test before fixing of insulators
Carrier pipe insertion with out damage to pipe, coating , insulators
Resistance test with megger between carrier and casing pipe : resistance
more than 100,000 ohm
Casing end sealed at both ends of the casing to prevent water injection,
soil ingress
Cased crossing

Both end double set of insulators
Maximum spacing of insulator as per
insulator manufacturer but not more
than 2500 mm
Carry out drain /vent perforation
holes arrangement in casing pipe
before insertion of carrier pipe
Typical cased crossing insulators arrangement

Size with respect to carrier pipe
As thumb rule – casing pipe is 6 inch
higher dia than carrier pipe however
thickness varies as per pipe dia
Size & thickness of casing pipe

What gauge plate indicates
Gauge pigging

Air Pigging cleaning and gauging
Cleaning with compressed air with the help of series of brush pigs
Gauge plate of softer metal like Aluminum of 95 % of internal dia of
highest wall thickness pipe fastened to pig
Retrieved gauge plate is analyzed and preserved
EGP locates exact location of dents
Following dents to be repaired
• 3.2 mm for cold-formed dents with sharp-bottom gouges and not
encroaching upon the specified minimum wall thickness.
• 6.4 mm for other dents.
• 1 mm at the pipe ends, i.e. within a length of 100 mm at each of the
pipe ends.
• Dents on weld and heat affected zone (HAZ)

Corrosion effect of pipe dent Ultra sound imaging of pipe dent
Effect of dents on pipeline

Hydrostatic test
Mechanical clearance is available after complete line alignment
inspection ( Pipe book completely approved)
NABL lab approved valid calibration certificates for Instrument and
equipment to be used
Water testing certificate and corrosion inhibitor dosage
recommendation
Checking the condition and sequence of pigs in hydrostatic header
Header fittings of appropriate rating
Only tested water to be filled along with CI PPM
Fill 500 M length water quantity before launch of first pig and 1000 m
water before 2nd pig
Final water filling done with filling rate of 2 KM/ Hr

Hydrostatic test
Prepare test plan with elevation sketches of sections based on hydraulic
profile so as
“The highest point of the test section shall be subjected to the minimum
test pressure ( 1.25 X Maximum design pressure) and the maximum test
pressure shall not be higher than 95% of specified minimum yield strength
(SMYS) of pipe material based on the minimum wall thickness in the test
section”
Say Pipe is 18"- API 5L GR. X70 PSL2 , 7.14 mm thickness
Design pressure is 99 Kg/cm2 and
So minimum pressure = 123.75 Kg/cm2
Maximum test pressure (as per API5L) : 137.22 Kg/cm2
So elevation difference 134.73 meter can be covered.
Hydro test section length for each section not exceeds 50 kilometers

After receipt of pigs at receiver minimum 2 hrs water flushing shall be
done.
Turbine meter reading recording shall be preserved
Thermal stabilization for 24 hrs shall be done and section is said to be
thermally stabilized if difference not higher than 1 degree is attained
between the average value of soil temperature readings
Warning boards : “KEEP AWAY- SYSTEM UNDER PRESSURE”.
No unauthorized person shall to be allowed during hydro testing.
Hydrostatic test

Pressurize section not more than 2bar/min
Following sequence to be maintained
a. Pressurise the pipe section to 50 % hold for 1 hour
b. Drop 0.5 bar DO air volume calculation
c. Drop pressure to static + 1 bar
d. Follow B & C for 75 % pressurization
e. If air volume calculation value is between 1 to 1.06, then filling is
accepted
The test accepted if difference is less or equal to 0.3 bar, in case of doubt
testing period shall be extended
Hydrostatic test

Restoration
Proper restoration a social responsibility & service by field engineer to
return some thing to farmer
Make contractor to relies farmers’ emotion & perform activity
Do not rely on documents for restoration but actual verify field &
• Video of area
• Photo graph of farmer with his farm land
Removing construction debris and de-compact soil in farm fields while
restoring rough grade
Restore separated topsoil back, repair fences and remove access points

Danger of HT over head lines
HT insulating mats in equipment
PPE & Shoes

Closing of trench opening
Animals ( Cat / Rat / Dog)
in pipeline
Sealing of pipe ends with
end cap
Falling of animals in Trench

Hazard at cased crossing pits
Tin sheet barricading
on road side
Adequate slope of
trench
Soil Graded : faster
exit way from trench
Water filling in Pit

Trench cuts in sloping sections.
No unauthorized person during hydro testing
Explosives storage precautions
Entrance prohibiting during radiography / blasting
Precaution in blast failed to fire, or is delayed,
Electrical firing for blasting
No blasting allowed within 20m of any existing pipeline or structure
(either above ground or underground).
Safety

Contractor Consultant
Owner
Balancing quality triangle

Quality aspects in Cross Country Pipeline construction

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