HYDRO-TEST REPORT
REPORT NO: ECL/HT/0005
PIGGING
LINE FILLING
PRESSURE TESTING
LEAK TIGHTNESS TEST
&
DEWATERING OF
4’’ Ø X 158m
ds
NIPCO Plc. Linkso Engineering &
Technical Services
Enikkom Construction Limited
ENIKKOM CONSTRUCTION LIMITED
No.7 Joseph Ogunjobi Street,Praise Hill Estate, Arepo
Lagos/Ibadan Expressway,Ogun State.Nigeria
Phone/Fax: 084 – 465792 & 750202
Email: info@enikkom.com

Table of Contents
1.0 ABBREVIATIONS 3
2.0 PURPOSE 4
3.0 SCOPE 4
4.0 SYNOPSIS 4
5.0 REFERENCE DOCUMENTS 4
6.0 TEST EQUIPMENT AND FACILITIES 4
7.0 CALCULATION FOR HYDRO TEST 6
8.0 SAFETY 10
9.0 SELECTION AND PREPARATION OF TEST SECTION 10
8.1 SELECTION OF TEST SECTION 10
8.2 PREPARATION OF THE TEST SECTION 10
10.0 LINE FILLING 14
11.0 HYDROSTATIC TEST 14
10.1 STRENGTH TEST 15
10.2 LEAK TIGHTNESS TEST 16
12.0 RECTIFICATION OF DEFECTS 16
13.0 ACCEPTANCE AND DEPRESSURIZATION 16
14.0 DOCUMENTATION 17
15.0 ATTACHMENT 18

1.0 ABBREVIATIONS
The following abbreviations are used freely in this document;
Abbreviation Description
GGL Green Gas Limited
ECL Enikkom Construction Limited
AG Associated Gas
ASME American Society of Mechanical Engineers
DP Design Pressure
EG Export Gas
MAWP Maximum Allowable Working Pressure
MAOP Maximum Allowable Operating Pressure
PEP Project Execution Plan
RPM Revolution per Minute
SMYS Specific Minimum Yield Stress
STP Specified Test Pressure

2.0 PURPOSE
The aim of hydrostatic test is to ascertain the integrity - strength and leak tightness of the 4”,8” & 12” dia
flow line/pipelines after fabrication, laying and installation by exerting a specified pressure @ 147 Bar
generated through water medium on the gas flowline/ pipelines.
3.0 SCOPE
This procedure covers the Flushing, Pigging, and Gauging and Hydrostatic Pressure testing of gas
pipelines, using corrosion inhibited water pumped from the dredged slot. Other considerations like
Dewatering, Drying and Nitrogen purging are for commissioning, while the introduction of the Product
into the line is Commissioning. These shall be covered under separate work procedure
.
4.0 SYNOPSIS
This work shall be carried out in accordance with the requirement of GGL Standard Construction
Specification.
The test section shall be prepared prior to pressurizing by cleaning, gauging and filling. For the gas
pipeline to be accepted, it must sustain the Specified Test Pressure (STP) for a defined period otherwise
cause of failure shall be detected, rectified and the gas /pipeline re-tested in accordance with the stated
pipeline specifications.
Prior to commencement of the test, sample of water to be used for filling, flushing and pressure testing
of the gas lines/pipeline shall be taken to GGL approved independent laboratory, tested and report
presented to the client representative for approval. GGL may equally carry out independent testing of
the water samples.
All necessary documentations as indicated in the specifications mentioned above, shall be carried out at
every stage of the activity. The detail test schedule which comprises the proposed test dates, locations
and the mobilization plan of the pressure testing crew shall be prepared and be made available to GGL
minimum of 3 days before planned test date.
5.0 REFERENCE DOCUMENTS
The following document will be referred to in determining the procedural requirement for carrying out
this work.
 DNV-OS-F101 Aug 2012 Sec.10 J210
 ASME B31.4 Para. 437.4 (Pipeline Transportation systems for liquid hydrocarbons and other
liquids)
 ASME B31.8 – Gas Transmission and distribution Piping System
 API RP 1110 (March 1997) – (Pressure Testing of Liquid Petroleum Pipelines)
 Pipeline Rule of Thumb, Hand Book
6.0 TEST EQUIPMENT AND FACILITIES
The test manifold shall be designed and fabricated in equivalent to at least 1.5 of the Maximum Allowable
Working Pressure of the gas flowline/ pipeline to be tested. Each major component of the testing
assembly shall be carefully inspected by visually and by radiography where necessary, and technically
certified by GGL. All measuring instruments required - Pressure / Temperature recorders, Pressure
gauges and Thermometers shall be calibrated to the specified accuracy and their certificates made
available to GGL for confirmation, minimum of 3 days prior to commencement of the hydro test. Besides,
the calibration status for each of the instruments shall also be documented in the ECL Hydro test
Instrument Calibration Record a copy of which is attached, after which a tag reflecting the calibration
date, expiry date and serial number of instrument is posted on each of the instruments.

At any point in time during the test, the actual position of a pig in the test section shall be tracked by using
the Volume, Speed and Flow rate of the driving medium (water) of the pig. These 3 variables shall be
determined from the flow meter installed across the water delivery line.
The test packages, schedule and necessary punch list shall be made available to GGL for review and
concurrence prior to hydro testing the lines. At completion of every hydro test, all items removed or
repositioned for the purpose of the test shall be reinstated. Efforts shall be made to ensure that the
environment in which the test is being carried out is preserved.
Listed below are the major components of the test assemblies which must be tested and certified by GGL
before commencement of this activity.
a. Flush Pump (Make KSB) – 6 Suction & 5 Discharge outlet (up to 30 Bar Pressure)
b. Pressure Pump 2” HP Pump (Union Pump) – (500 bar)
c. High Pressure hoses 206.86n /3000 psi
d. Mannesmann Compressor 15bar Maximum Pressure
e. Ingersoll-Rand XP 750 cfm Compressor
f. Flow meter Serial No. 96AWQ24432
g. 12” Hight Density Criss Cross Foam Pig w/t Wire Brushes
h. 12” Medium Density Criss Cross Foam Pig
i. Silver Gauging plates wt 7-9mm and OD 266mm
j. Pig Launcher/Receiver 12’’ Ø
k. ITT BARTON Pressure / Temperature Recorder -3000PSI, 150oF and 24Hr. 9 Days Wind
(S. # 435167, Model # 3452E)
l. Temperature Charts
m. Pressure Gauges Wika (0-160 Bar)
n. Pressure Guage (0-400 Bar)
o. Pressure testing header
p. Cork Valves
q. Flexible and high pressure flushing Hose and couplings
r. Water Tanks
s. Pressure relief Valve 0 – 155 Bar

7.0 Calculation for Hydro test
S.No Description
1 12” Dia Pipe OD 323.85mm
2 12” Dia Pipe ID 304.8mm
3 Length of First Hydro test Section 8997m 8,997 Meter
4 Length of 2nd Hydro Test Section 2,750m 2,750 Meter
5 Volume of 1st Section (73 Ltr. Per Meter) r2 h Or L
3.14*(0.152)2 *8997*1000
649.481m3
6 Volume of 2nd Section (73 Ltr. Per Meter r2 h Or L 200.75m3
7 Wall thickness of Pipe 9.525mm
8 45 Degree Bend OD 323.85
9 45 Degree Bend ID 279
10 Wall Thickness of Bend 22.53
11 90 Degree Bend OD 323.85
12 90 Degree Bend ID 279
13 Wall thickness of Bend 22.53
14 Gauge Plate OD is Minimum 95% ID of Bend 265.05
15 Design Pressure 98 Bar
16 Hydro test Pressure 150% of Design Pressure 147 Bar
17 Pressure Elevation Difference due to Ground Elevation (First Section) 2.3 Bar
18 Pressure Elevation Difference due to Ground Elevation (2nd Hydro
Test Section)
2.5 Bar
19 Minimum Depth of Pipeline 1.5 Meter
20 Maximum Depth of Pipeline Ch 002+750 to CH 11+747 (8,997m) First
Section
23 Meter
21 Maximum Depth of Pipeline CH 0+000 to Ch 002+750 (2,750m) 2nd
Section
36 Meter
22 Using the rule of thumb for 10m height of water = 1barg
Back Pressure due to Elevation Ch 002+750 to CH 11+747 (8,997m)
1st Section
2.15 Bar
23 Using the rule of thumb for 10m height of water = 1barg
Back Pressure due to Elevation CH 0+000 to Ch 002+750 (2,750m)
2nd Section
3.5 Bar
24 Friction loss Calculation During Filling(See the Formula onNext Page) 1.07 Bar
25 Total Back Pressure due to Elevation Ch 002+750 to CH 11+747
(8,997m) 1st Section (Sn13+SN18+SN19)
5.52 Bar
26 Total Back Pressure due to Elevation Ch 002+750 to CH 11+747
(8,997m) 1st Section (Sn14+SN18+SN19)
7.07 Bar

Rule of thumb for 10m height of water (Formula)
P=rho*g*h
P= pressure
rho= density = 1000 kg/m^3 at about 20C
g= gravitational constant on earth at sea level = 9.81 m/s^2
h= height
h= 1x10^5/(1000*9.81)= 10.19367 meters
The friction loss calculated using Hazen Williams formula
f = 0.2083 (100 / c)1.852 q1.852 /dh4.8655 (1)
where
f = friction head loss in feet of water per 100 feet of pipe (fth20/100 ft pipe)
c = Hazen-Williams roughness constant = 120
q = volume flow (m3/s) =0.31 @0.5m/s
dh = inside hydraulic diameter (m) =0.91
Actual Frictional Head loss ≈ 1087otal /b8.5mmH20 = 1.07bar
Table 6 – Expected Total Back Pressure for different types of Pig / Line Filling
Pig Types
DP
(Bar
g)
Static
Head
(bar)
Back
Pressure
(bar)
Frictional
Head Loss
(bar)
Safety Factor
2.5 Bar
Total Back
Pressure
(bar)
1st Section
Filling
Water
0
2.30 2.15 1.07 2.5 8.02
Foam Pig 0.19 2.30 2.15 1.07 2.5 8.21
cup pig 0.22 2.30 2.15 1.07 2.5 8.24
Bi-di Pig 0.39 2.30 2.15 1.07 2.5 8.41
coated
foam pig
0.41
2.30 2.15 1.07
2.5
8.43
Brush Pig 0.62 2.30 2.15 1.07 2.5 8.64
2nd Section
Filling
Water
0
2.5 3.5 1.07 2.5 9.57
Foam Pig 0.19 2.5 3.5 1.07 2.5 9.76
cup pig 0.22 2.5 3.5 1.07 2.5 9.79
Bi-di Pig 0.39 2.5 3.5 1.07 2.5 9.96
coated
foam pig
0.41
2.5 3.5 1.07
2.5
9.98
Brush Pig 0.62 2.5 3.5 1.07 2.5 10.19
For this project the expected backpressure for pigging activities can be estimated to fluctuate between 6 – 8
bars and additional 2.5 bar might be a safety factor taking into consideration heavy wall sections of road
crossings, HDD and bends.
Filling and Cleaning Pump Requirements.

The pump required for the operation must be rated to 1.25 times the expected backpressure. Therefore the
expected discharge pressure for the pump is approximately.
1.25 * 10.19 bar ≈ 12.74 bar
 The discharge pressure rating for the pump recommended for this operation must be able to discharge at
a pressure capacity well above 12.74 bars.
The pig speed in a normal pigging operation should be within 0.5 – 1m/s if we assume a maximum pig speed
of 1m/s for this operation the equivalent flow rate would be = 8997/1 = 8997 s =2.5h
Flow rate = 649.481/2.5 = 4.32m3 /mins = 4.32*6.289= 27.01 BPM (1m3 = 6.289 Barrel)
Compressed Air Design
 The pig speed should be between 2 – 8km for normal pig runs and 2 -4km/h for gauging plate runs while
using compressed air as a medium to propel the pig,
By assuming an average pig speed of 4km/h the air flow required
= (649.48 / 8,997) * 4,000 = 289 m3/h = V1
The required driving pressure when the pipeline is full of water must
Total Driving pressure required ≈ 12.74 bar = P1
Total Back pressure = 10.5 = P2
Using equation = P1*V1 = P2*V2
V2 = ( P1*V1 ) / P2 = ( 12.74 X 289 ) / 10.5
V2 = 350.65 m3/h
@ 1 m3 = 35.315 CFM
Compressed air requirement = 350 x 35.315 = 12,383ft3/h = 207 CFM
To give allowance for error in calculation 1.25 time the required air will be used = 259CFM
Therefore, a 650 CFM @ 15 Bar compressor should be adequate for the project. To achieve an 8km/hr pigging
speed a second compressor would be added while a third would be on standby for in case of breakdown.
The pig delivery time at average speed of 4-8km/hr ≈ less dawn 2 – 4 hours
1. HYDROSTATIC TEST PUMP DESIGN
The pressurizing pump required should be suitable to pressurize the test section at approximately 1 bar per
minute. The volume required to inject to give 1bar pressure can be estimated using the theoretical equation
for volume change ∆V per Pressure change ∆P for pipeline with liquid under pressures at constant
temperature, disregarding effects of air absorption or free air in the line. The Pressure-volume relationship
considering elastic strain in the pipe and Compressibility of the water is calculated thus
∆𝑉 = (
𝐷
𝐸 ∗ 𝑡
∗ ( 1 − 𝛾2) +
1
𝐵
) ∗ ∆𝑃 ∗ 𝑉
DV/DP = V * [(D/ (E * t) (1 – v²) + C]
Where,
dV = incremental volume in the same units as V
dP = incremental pressure, bar = 1
V = volume of the segment 1 = 649.481m3
V = volume of segment 2 = 200.75m3
V = Volume of the Segment 2 = 200.75m3

D = Outside diameter (m), = 0.314m
E = Elastic modulus of steel pipe (psi) = 2.07 x 10*6
t = Wall Thickness of pipe (m)= 0.0095m
v = passion’s ratio steel pipe = 0.3
C = Bulk compressibility factor of liquid, per psi (the reciprocal of the bulk modulus)=
46.7 x 10*-6 bar
DV/DP = V * [(D/ (E * t) (1 – v²) + C]
DV/1 = 649.481 [0.314 / (2.07x10*6) x 0.0095) (1-0.09) + 46.7 x 10*-6]
= 649.481 [0.314/(14697)(0.91) +46.7x10*-6]
= 649.481 [0.314/13374.27)
DV = 0.02m3/min
The test pump required for this project should be capable of pumping at approximately 0.3m3 per minute at
the required test pressure.
Theoretically pressurizing the system from zero to test pressure should be directly proportional to inject
volume as calculated above, due to the pipeline profile air entrapment is expected, careful estimation of the
air entrapment would be carried out and fillingprocess would be done with high sealing pig to reduce air
entrapment in the test system.
Pipe Drying
Most of the data uses for this estimate are theoretical but in the final analysis allowance would be given for
practical field situation.
The air dew point inside the pipeline is assumed to be the same as pipe wall temperature at 15degree C
therefore, the moisture content of the air estimated on I-X graph = Xm = 12.8 g/m3.
Dry air system temperature at Outlet (-30 degrees Centigrade dew point) Xout = 0.33 g/m3
The system flow rate Vr is design for 1180 m3/h (expected compressed air capacity equivalent to what air
dryer can handle @ required departing pressure of 0.5 – 1bar pigging pressure)
N.B – The capacity can be adjusted on the field depending on field criteria and client interest)
The moisture removal capacity of the dry air system Vm =
Vm = Vr (Xm-Xout) /1000
Vm = 1180 (12.8-0.33)/1000 = 14.72 kg/h
The expected remaining water in the pipeline after successful dewatering, assuming a water film of 0.1 mm.
Remaining water = W= 3.14/4(D12-D22)*L*1000
W = 3.14/4(0.3142- 0.2952)* 8.997*1000 = kg water
=0.00908 x 8997
= 82 kg of water
The total drying time for this project T:
T = W/Vm
T = 82 / 61.85 = 5.57 hours

8.0 SAFETY
a. Care shall be taken to open or close any valve too quickly
b. Closed valves shall be electrically isolated or locked out (depending on the client’s operating
system). The vents on the valve bodies should be opened where applicable.
c. Work area associated with the launcher and receiver test header traps shall be cordoned off as a
no-entry area for non-authorized persons.
d. Warning signs marked “STAY CLEAR –PRESSURE TESTING IN PROGRESS” and hazards tapes shall
be installed.
e. An experienced Safety Officer will be available to ensure safety at all times during pressure testing.
9.0 SELECTION AND PREPARATION OF TEST SECTION
7.1 SELECTION OF TEST SECTION
The test section shall be the entire completed line or section of line on which there will be no further
work between the inlet and outlet. The elevation difference in the test section shall not exceed 5%
of the SMYS of the flow lines or 50m. Also, the inlet and outlet of the test section shall be provided
with suitable flanges to enable pigging and temporary coupling of the test head and the pig
launcher/receiver.
7.2 PREPARATION OF THE TEST SECTION
NDT reports for all welds and repairs on the line to be hydro tested shall be cross checked again by
ENIKKOM CONSTRUCTION LIMITED QA/QC Engineer and confirmed by the GGL Representative to
ensure that all welds/repairs meet the minimum standard of acceptability stated inDEP 61.40.20.30-
Gen., before commencement of any of hydro test activity.
Prior to pressure testing, each line shall be cleaned by flushing and Pigging to remove construction
debris and other loosely adhered material on the metal and ensure that the line is free of deformation
and obstructions. These pre-test activities shall be continuously carried out until the requirements
of GGL are satisfied. The physical content and color of the discharge water determines the level of
cleanliness of the flow line. Detailed procedure for the execution of each of the activities highlighted
above is stated as follows:

PROCEDURES ACTION PARTY
1. The launch and receiver trap dimension shall be assessed and
adjudged capable of accommodating the pigs
2. All necessary equipment is available for the work
3. Ensure that Permit to Work and relevant permits are obtained for
the proposed test
Project Engr
4. Prior to the installation of the testing assemblies at each end of The
gas pipeline/, ensure each component of the assemblies are
thoroughly inspected and all measuring instruments currently
calibrated
Test Supervisor/QC
Engr
5. Check and use competent personnel Test Supervisor
6. Set up warning signs, danger signals, and safety barricade about
20m away from the test locations.
Safety Officer
7. Ensure no other work is permitted on the test section during the
period of the pressure testing.
Field Engr/Test
Supervisor
8. Reemphasize as stated in the ENIKKOM CONSTRUCTION LIMITED
Emergency Procedure in ENIKKOM CONSTRUCTION LIMITED PEP
the actions and responses of the pressure testing crew members in
case of emergency.
Safety Officer
9. Establish and maintain walkie-talkie or mobile link between the
crew members
Field Engr/ Test
Supervisor
10. Define the boundaries of the test equipment sites with safety hazard
tapes.
Safety officer

8.1.1 FLUSHING/PIGGING
11. Connect the flushing pump and accessories to the
pipeline/flow line in readiness for flushing.
Pressure Testing
Technician
12. Introduce water from the client approved source
corresponding to minimum of 2% of the section volume,
to wash away the foreign materials.
Pressure Testing
Technician
13. Repeat step 11 until the pipeline / flow line is acceptably
clean to the satisfaction of the GGL Representative, for the
first pig (bi– directional type) to be introduced.
Pressure Testing
Technician
14. Connect the pig trap/receiver together with the throttling
valve set -up at the discharge end of the line prior to
introduction of the first bi-directional pig.
Pressure Testing
Technician
15. Ensure the GGL Representative is present before the
commencement of any pigging operation.
Field Engr./ Test
Supervisor
16. Alert the recording technician to get pig register copy of
which is attached and other necessary documents ready
and ensure the by-pass of the bi – directional pig is kept
open before inserting the pig.
Field Engr./ Test
Supervisor
17. Make necessary connections and drive the bi-directional
pig by with water through the line to be received into the
pig receiver at the discharge end.
Pressure Testing
Technician
18. As the bi – directional pig moves in the line, its speed shall
be controlled within the range of 0.5m/s - 2.5m/s by
adjusting the throttling valve connected to the receiving
end, in order to ensure effective cleaning of the line.
Pressure Testing
Technician
19. Repeat step 16 and 17 using cleaning brush pig installed
in succession so long the volume of the discharged
material is not lesser than 5 liters. Notwithstanding, the
pigging shall still be done to the satisfaction of the GGL
Representative before proceeding to gauging.
Pressure Testing
Technician
20. Clear the immediate surroundings of the discharge end of
the line of debris received with the pigs and dispose in
accordance with ENIKKOM CONSTRUCTION LIMITED
Waste Management Procedure, A temporary piping shall
be fabricated to transport the waste water from the test
sections into the waste disposal area.
Safety Officer / Helper
8.1.2 GAUGING
21. When the test section has been accepted clean by the
Client Representative, then the bi-directional pig with
2 sets of separate guiding and sealing discs shall be fitted
with one or two aluminum gauging plate and located as
stated insection of the DEP 31.40.40.38 – Gen. Ensure the
gauging plates are inspected by the GGL Representative
before driving them into the test sections. The gauge
pjlate is dimensioned to the 95% of the smallest possible
ID of the pipeline.
Field Engr/Test
Supervisor
22. After the inspection, the gauging pig shall be introduced
into the test section and driven through the line to be
received into the pig trap at the discharge end.
Pressure Testing
Technician

23. Repeat step 17 as the gauging pig is being driven through
the test section.
Pressure Testing
Technician
24. At the emergence of the gauging pig from the test section,
the plate shall be inspected by the Test supervisor and
GGL Representative for bending, notching and other
irregularities as specified in the above mentioned
specification.
Client Representative/
Field Engr / Test
Supervisor
25. Photographic records of condition of the aluminum
gauging plate shall be kept after each test
Test Supervisor /
Photographer
26. In situation where the aluminum gauging plates do not
meet the acceptance criteria inthe specification, the cause
of the defect shall be located, rectified and the gauging pig
re-run until it emerges in an acceptable condition.
Field Engr/Test
Supervisor / Pressure
Testing Technician
27. In case any of the test pigs gets stuck in the test section
and cannot be removed by the normal pumping pressure
high density pigs shall be used to unblock the line failing
which the line shall be cut to remove the pig. Then, the
defect shall be repaired in accordance with appropriate
construction specification and the qualified ENIKKOM
CONSTRUCTION LIMITED Weld Repair procedure.
Field Engr/Pressure
Testing Technician

10.0 LINE FILLING
28. Once cleaning of the bore of the test section is accepted by the GGL
Representative, the open end of the test section shall be blinded off and
a valve is connected for back pressure control and venting to remove air
from the line during filling.
Test Supervisor/
Pressure Testing
Technician
29. Ascertain from the GGL if the line will be left empty or unused for more
than 7 days. In that case, add the correct concentration of a GGL
approved corrosion Inhibitor to the filling water.
Field Engr/Pressure
Testing Technician
30. Ensure the suction end of the pump is fitted with a strainer and does not
draw air by keeping it well below the head of water required to fill the
line.
Field Engr/Pressure
Testing Technician
/Helper
31. The line shall be filledusing 2 bi-directional pigs with water in front and
in - between to ensure complete removal of air. The line is filled when
the second bi-directional emerges.
Field Engr/ Test
Supervisor
32. After the line has been completely filled, hydro testing can commence. Field Engr/ Test
Supervisor
11.0 HYDROSTATIC TEST
The line shall be subjected to the Specified Test Pressure stated in section IV-3 (GGL Scope of Work for
new pipelines, bulk lines and lift gas distribution) of GGL Contract Document.
S. # Line Size
Material
Specification
Design Pressure
(barg)
Test Pressureure
Barg
5 12’’Pipeline X52 98 147
33. Disconnect the filling pump and connect the high pressure pump, hoses
and the pressure testing manifold ready to pressurize the line.
Test Supervisor /
Pressure Testing Tech.
34. Double check the pressure-testing manifold to ensure all its components
are still in order using the pre- test checklist copy of which is shown in
appendix C.
Field Engr/Pressure
Testing Technician
35. Check again to ensure all warning signs, safety hazard tapes and
barricades are still in place.
Safety Officer
36. Provide a canopy to shelter the pressure-testing header before
pressurizing the pipe to prevent temperature variation.
Field Engr/ Test
Supv/Pressure Testing
Technician
37. Commence pressurization by raising the pressure at constant rate of
1bar per minute up to 30 bar or 20% of the Specified Test Pressure
(STP) for each test section.
Pressure Testing
Technician
38. During this period the graph of pressure (Y-axis ) against water input
volume shall be plotted at minimal 1 bar interval
Test Supervisor / Field
Engineer
39. During this period, check thoroughly for leakage on all exposed part of
the test section and test manifold fitting and connections.
Field Engr/ Test Supv/
Pressure Testing
Technician
40. After satisfactory completion of the 2hours pressure holding period and
leak check, raise the pressure at a constant rate of 1 bar per minute up
to 70% of the STP
Pressure Testing
Technician
41. During this period the volume and pressure readings should be
recorded at 10 minutes intervals until the 70% of the STP is reached.
Pressure Testing
Technician
42. During this water pressure stabilization period accessible flanges
shall be checked again for small leaks. If any are found, the line shall
be depressurized at the rate of 2 bar/min to 70bar or to MAOP,
whichever is lesser, prior to bolt tightening
Field Engr/ Test Supv /
Pressure Testing
Technician
43. If no leak is found, the pressure shall be built up at the rate of 0.5
bar/min to 95% of the STP and held for 30 minutes, after which
pressurization shall be continued to the STP of the line.
Pressure Testing
Technician

10.1 STRENGTH TEST
44. After attainment of the STP specified in Section IV-3 of the
GGL Contract document the pressure shall be held at this
point for 1 hours.
Field Engr/ Test Supv /
Pressure Testing
Technician
45. During strength test the test pressure shall be recorded
continuously on the dead weight tester readings and the air
temperature recorded at every 30 minutes.
46. The Pipe and ground temperature shall be recorded at the
beginning and the end of the 1 – hour test period, while the
ambient temperature is recorded continuously.
Field Engr/Pressure
Testing Technician
47. Ensure that the pressure is maintained at the STP +/- 1 bar
by bleeding or adding water as required.
Pressure Testing
Technician
48. If a leak is suspected, actions shall be taken as stated in
section 13.0 of this procedure to rectify it. Afterwards, the
strength test shall be repeated.
Field Engr / Test
Supervisor / Pressure
Testing Technician
49. After satisfactory completion of the strength test, disconnect
the high pressure pump and blank off all necessary
connections. Ensure the STP is still maintained while
carrying out these disconnections.
Pressure Testing
Technician

10.2 LEAK TIGHTNESS TEST
At satisfactory completion of the strength test, the leak tightness
test shall commence immediately to confirm there is no leak inthe
line. This test shall last for 24 hours. The leak tightness test
pressure for each of the test sections shall be equal to the strength
test pressure.
Pressure recorder chart shall be signed by GGL Representatives
just prior to commencing pressurization.
50. At confirmation of the STP, start off a new chart in the 24-
hour pressure recorder and take first set of pressure and
temperature readings. After that, log in the pressure and
temperature readings at 30 minutes interval. The
temperature recording interval shall reduce to 1- hour
duration for the first and last 3-hour periods of the 24 hours.
The pipe and soil temperature shall be recorded at maximum
3 – hour interval.
Field Engr/Pressure
Testing Technician
51. Monitor line on test to observe any pressure drop or build up
within the 24 - hour period.
Field Engr/Pressure
Testing Technician
52. The test pressure in the line may drop or build up due to
temperature changes. If pressure build up due to
temperature becomes excessive, seek clearance and bleed
line to acceptable limit.
Field Engr/Pressure
Testing Technician
53. The pressure testing of the line shall end when the chart is
submitted and accepted by the GGL Representative.
Field Engr/Test
Supervisor
54. Ensure the ambient temperature and the pipeline water
temperature are recorded at the same time as the pressure
readings.
Field Engr/Pressure
Testing Technician
12.0 RECTIFICATION OF DEFECTS
All established leaks shall be located by dividing the entire line into two sections and each of the sections
will be subjected to full pressure inaccordance with this procedure. After this test, the section that shows
signs of leakages will again be divided into two halves and tested independently. This procedure shall be
repeated until finally the leaking point is established on a short section. The defect detected during the
test shall be rectified in accordance with the appropriate GGL approved specification and ENIKKOM
CONSTRUCTION LIMITED Weld Repair Procedure. After the rectification process, the damage / defect
detected and the repair carried out shall be documented and the report made available to GGL.
All defective materials - Pipe and fittings shall be identified and isolated from other good materials. Being
GGL material(s), they shall finally be disposed off in accordance with the GGL Representative's advice.
13.0 ACCEPTANCE AND DEPRESSURIZATION
The hydrostatic test shall be considered successful and accepted when the STP has been held for 24 hours
with no significant loss of pressure. The hydrates certificate shall be completed and signed by ENIKKOM
CONSTRUCTION LIMITED Representative and submitted to the GGL Representative.
55. After satisfactory completion of the strength and leak tightness tests
open the pressure let-down valve slowly to depressurize the pipeline
/ flow line.
Field Engr /
Pressure Testing
Technician
56. The test section shall be depressurized at the rate of 1 bar per minute
up to the hydrostatic head plus 1 bar to prevent air from entering it.
Ensure proper control of the pressure let-down valve to avoid vibration
of the pipeline/flow line.
Field Engr /
Pressure Testing
Technician

57. Ensure the test pressure is never used to transfer water into another
pipeline / flow line
Field Engr/Test
Supvr
58. Ensure all test plots, records and charts are countersigned by GGL Site
Representative. Afterward, the consent of the GGL Representative shall
be sought for Dewatering.
Field Engr/ Pressure
Testing Technician
59. Firmly close off all valves. Ensure Gauge locks and pressure gauges are
installed both ends of the tested section to monitor the pressure, then
hand over the line to GGL representative.
Field Engr/ Pressure
Testing Technician
60. Reinstate all materials – fittings, piping etc, that were repositioned for
the purpose of the test.
Field Engr/ Site
Supv.
61. Ensure all valves on the facilities linked to the pipelines/ flowlines
that were closed or opened during the test, are returned to their
position.
Field Engr/ Site
Supv.
62. Clean up all dirt and debris accumulated from the test. Field Engr/ Site
Supv.
63. Using the Acceptance and Depressurization Checklist double check that
proper reinstatement had been done. Invite the GGL Site Representative
to confirm it .before demobilizing.
Field Engr/ Site
Supv.
14.0 DOCUMENTATION
Records of all parameters mentioned in this procedure shall be kept during each operation. Hydrostatic
pressure test records shall be reviewed by GGL in the beginning, at the end and at least once during the
test.
The ENIKKOM CONSTRUCTION LIMITED Representative shall sign every recorder chart before and after
placing it on the recorder. For recorder charts taken during the hydrostatic pressure, the GGL
Representative shall sign them.
Upon successful completion of the test a “Hydrostatic Test Certificate” shall be completed and signed by
both the ENIKKOM CONSTRUCTION LIMITED and GGL representatives (ECL/GGL) and backed up by
original hand – written test data of which photocopies is given to the GGL representative.
A comprehensive hydrostatic report with general introduction including all relevant pipeline data, and
detailing shall be compiled for each test section and submitted to GGL. The contents of this report, as a
minimum, shall include all documents highlighted.14.0 Attachment.

15.0 ATTACHMENT
S. # Description Reference
1. Pigging Record Attachment # 01
2. Line Filling Log Attachment # 02
3. Pressurizing Report Attachment # 03
4. Hydro Test Report Attachment # 04
5. Hydro Test Certificate Attachment # 05
6. Schematic of Test Section Attachment # 06
7. Pressure/Temperature Recorder Charts Attachment # 07
8. Calibration Record Attachment # 08
9. Gauge Plate Photographic Record Attachment # 09
10. Check List Attachment # 10

ATTACHMENT 1.0
REPORT NO: ECL/HT/0005/01
ENIKKOM CONSTRUCTION LIMITED
PIGGING RECORD
PROJECT:…LAYING OF NATURAL GAS PIPE LINE NIPCO II TEST
DATE:……………10/05/2016……………………………………
PIPE DATA
Pipeline Identification: 4’’DIA PIPELINE AT NIPCO LAND FROM (CH 0+ 0.00) TO (CH 0+158.46).
Pipe Diameter:…4.5’’……… Grade……………. W.T.:…6.4mm……… Length:…158m………………..
Location: NIPCO LAND Activity/Phase…PHASE II……………………………
PIG DATA
S/
N
DATE PIG TYPE
PIG
LAUNCH
TIME
PIG
RECEIVE
TIME
PEAK
PRESSUR
E
ARRIVAL
CONDITI
ON OF
PIG
VOLUME OF
FOREIGN
MATERIAL
DISCHARGE
WITH PIG
1
10/5/16 M. Density
foam Pig.
14:45HRS 14:56HR 2.0SSBAR Okay Clean Water.
Propelling medium:…………WATER……………………………………………………………
REMARKS
……………………………OKAY……………………………
For ENIKKOM CONSTRUCTION LIMITED For LINKSO NIGERIA LIMITED.
Name……………………………………… Name………………………………….
Sign / Date……………………………….. Sign / Date…………………………
For REFLECT ENGINEERING SERVICES LTD.
Name………………………………………
Sign / Date………………………………..

ATTACHMENT 2.0
REPORT NO; ECL/HT/0005/02
ENIKKOM CONSTRUCTION LIMITED
LINE FILLING LOG
Project:…… LAYING OF NATURAL GAS PIPE LINE NIPCO PHASE II …
Pipeline Identification: 4’’DIA PIPELINE AT NIPCO LAND FROM (CH 0+ 0.00) TO (CH 0+158.46).
Pipe OD:…4.5’’…………………….. Pipe W.T…6.4mm……………. Pipe Length…158m……………….
Estimated pipeline volume (m3):……1,281.1 litres…………………….
Type of line-fill water…………Clean Fresh Water…………………………………………………………..
Type of line-fill water treatment (if applicable)………N/A………………………………….
Temperature of line-fill water………oC, Average Temp of Surrounding Soil:………oC
DATE
TIME
(hours)
PUMP DISCHARGE
PRESSURE (bar)
CUMULATIVE WATER
VOLUME PUMPED
(m3)
10/05/16
10Min 1.0 Bar 1,281.1 Litres.
Total Volume
Pumped.
1,281.1 Litres
REMARKS
………………………………………OKAY……………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………………………………………………………
……………………
For ENIKKOM CONSTRUCTION LIMITED For LINKSO NIGERIA LIMITED.
Name……………………………………… Name………………………………….
Sign / Date……………………………….. Sign / Date……………………………
For REFLECT ENGINEERING SERVICES LTD.
Name………………………………………
Sign / Date………………………………..

ATTACHMENT 3.0
REPORT NO; ECL/HT/0005/03
ENIKKOM CONSTRUCTION LIMITED
HYDROTESTING
Sheet 1 of 2
Project:……LAYING OF NATURAL GAS PIPELINE, NIPCO PHASE II…………………
Pipeline Identification: 4’’DIA PIPELINE AT NIPCO LAND FROM (CH 0+ 0.00) TO (CH 0+158.).
Pipe OD:……4.5’’………………….. Pipe W.T…6.4mm……………. Pipe Length…95m.……………….
Date of Hydro testing:……………08/05/16……………………….....................................................
Initial Pipe Temperature at Pressurizing…….34.3 oC, Time………..15:16…h
Initial Testing Pressure……0…bar, Final Testing Pressure….147….bar.
Pipe Temperature at 80% of Pressure….37.5 oC, Time………….h.
Air Content……..Nil..% of the line volume, Test Pressure:…147………..bar
STRENGHT TEST
DATE
TIME
(hours)
PIPELINE PRESS.
(bar)
PIPELINE GUAGETEMP.
(oC)
10/05/16 15:13 – 15:14 0 - 35 31.8
15MINS HOLD FOR
OBSERVATION DOWN TO
15:29HRS.
10/05/16 15:30 – 15:31 35-104 33.0
15MINS HOLD TO
15:50HRS.
10/05/16
15:50 – 15:51 104 – 140.5 33.0
10 MINS HOLD TO
16:05HRS.
10/05/16
16:03 – 16:04 140.5 - 148 32.1
60MINS HOLD TO
17:06HR
VISUAL INSPECTION
(Carried out at 80% of the strength test pressure)
Pipe Temperature at 80% of Test Pressure…32.1 oC, Time…………15:51…………….. h
Result:……OKAY……………………………………………………………………………………………………………………………………………
…………………………………...…………………………………………………………………..……………………………………………………………
………………………………..…………………………

Sheet 2 of 2
LEAK TIGHTNESS TEST
DATE
TIME
(hours)
P.PRESS.
GUAGE
@RECOR
DER SIDE
(bar)
P.PRESS.
GUAGE 2
@RECOR
DER SIDE
(bar)
GUAGE
PIPELINE
TEMP.
( oC)
SURF
SOIL
INFRARE
D TEMP.
( oC)
AIR
INFRARED
TEMP.
( oC)
REMARK
10/5/16 17:06 148 148.5 30.4 26.6 25.7
10/5/16 18:06 148 148.2 28.2 25.9 25.6
10/5/16 19:06 147 147 27.2 25.7 24.5
10/5/16 20:06 147 147 26.0 25.0 24.0
10/5/16 21:06 146 146.5 24.8 23.9 22.7
10/5/16 22:06 145.2 145.5 23.5 23.2 22.6
10/5/16 23:06 144 145 22.0 22.1 20.2
11/5/16 00:06 144 144.5 21.5 22.2 19.8
11/5/16 01:06 144 144.5 21.5 22.0 19.6
11/5/16 02:06 144 144.5 1.5 21.7 19.5
11/5/16 03:06 144 144.5 21.0 21.5 19.5
11/5/16 04:06 143.5 144 21.0 21.5 19.3
11/5/16 05:06 143 144 22.0 20.8 19.0
11/5/16 06:06 142 143 22.0 20.4 19.1
11/5/16 07:06 141.5 142 22.5 23.8 22.7
11/5/16 08:06 141.6 142 26.8 24.0 30.0
11/5/16 09:06 142 142 30.2 32.1 28.2
11/5/16 10:06 142.3 143 33.8 34.5 28.8
11/5/16 11:06 144 144.5 35.2 39.0 29.5
11/5/16 12:06 144.5 145.0 39.0 39.4 32.2
11/5/16 13:06 145
11/5/16
11/5/16
11/5/16
11/5/16
COMMENT(S)
……………………………………………………………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………………………………………………
For ENIKKOM CONSTRUCTION LIMITED For LINKSO NIGERIA LIMITED
Name……………………………………… Name………………………………….
Sign / Date……………………………….. Sign / Date……………………………
For REFLECT ENGINEERING SERVICES LTD
Name………………………………………
Sign / Date………………………………..

ATTACHMENT 5.0
REPORT NO; ECL/HT/0003/05
ENIKKOM CONSTRUCTION LIMITED
DEWATERING RECORD
Project:……LAYING OF NATURAL GAS PIPELINE, NIPCO PAHSE II…………………
Date :……………27 & 28 – 05 - 2016……………………….....................................................
PIPE DATA
Pipeline Identification: 12’’DIA FROM SHAGAMU INTERCHANGE (KP27+972.20) TO CDK (KP29+38.70).
Pipe OD:……12’’………………….. Pipe W.T…9.53mm……………. Pipe Length…1.066Km.……………….
Location…. SHAGUMU INTERCHANGE……. Activity/Phase…….Phase II………….
S/N DATE PIG TYPE
PIG
LAUNCH
TIME
PIG
RECEIVE
TIME
PEAK
PRESSURE
(Bar)
ARRIVAL
CONDITION OF
PIG
1 27/06/16 Coated Form
Pig.
20:23 20:40 2.7 Okay with Much
Water.
2&3
27/06/16
M.D Foam
Pig.
21:25 21:34 1.2 Little Water.
4 28/06/16 M.D Foam
Pig.
10:36 10:42 0.7 Okay with No
Water.
5
28/06/16
Coated Foam
Pig.
11:09 11:15 0.5 Okay with No
Water
6
28/06/16
M.D Foam
Pig.
13:12 13:20 1.0 No Water.
7&8
28/06/16
M.D Foam
Pig.
14:58 15:07 0.8 No Water.
Propelling medium ………..AIR……………………………………………..
REMARKS
………………………………………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………………………………….
For ENIKKOM CONSTRUCTION LIMITED For LINKSO NIGERIA LIMITED
Name……………………………………… Name………………………………….
Sign / Date……………………………….. Sign / Date……………………………
For REFLECT ENGINEERING SERVICES LTD
Name………………………………………
Sign / Date………………………………..

ATTACHEMNT 6.0
ENIKKOM CONSTRUCTION LIMITED
HYDROTEST CERTIFICATE
Project…LAYING OF NATURAL; GAS PIPELINE, NIPCO PHASE II……………………………………………
Client………NIPCO PLC………………………………………………………………………………
Contract No:………………………………………………………………………………
Location: SHAGAMU INTERCHANGE.
THIS IS TO CERTIFY
That the pipeline or flow line section described in this certificate was pressure tested in accordance with the
terms of the following Specifications:
Specification: 12’’ X 1.066 Km (CLASS 1 ASME B31.8)
Pipeline identification: 12’’DIA FROM SHAGAMU INTERCHANGE (KP27+972.20) TO CDK (KP29+38.70)
Testing Location: SHAGAMU INTERCHANGE.
Pipe OD (mm): 323.85 Pipe W.T. (mm): 9.53 Pipe length (m):1066
Nominal Test Pressure (bars): 147
Final test pressure at testing location (bar): 147
Reference Pressuring Report No: ECL/HT/0003/03
Reference Hydro test Report No: ECL/HT/0003/04
Description and reasons of leaks: NIL
Residual pressure inside pipeline upon test operations (bar): 147.
Final Result:
For ENIKKOM CONSTRUCTION LIMITED For LINKSO NIGERIA LINITED.
Name……………………………………… Name………………………………….
Sign / Date……………………………….. Sign / Date………………………………..
For REFLECT ENGINEERING SERVICES LTD
Name………………………………………
Sign / Date………………………………..

ATTACHMENT 7.0
PRESSURE / TEMPERATURE RECORDER CHART

ATTACHMENT 8.0
HYDROTEST INSTRUMENTS CALIBRATION RECORD
S/N EQUIPMENT DESCRIPTION
MODEL/
SERIAL NO
CALIBRATION
DATE
EXPIRY
DATE
EQUIPMENT RECALL
DATE FOR
RECALIBRATION
RECALIBRATION
DATE
REMARK
Note: This record sheet shall be completed when all instruments to be used for hydro test of the pipelines / flow lines have
been duly calibrated.

ATTACHMENT 9.0
ENIKKOM CONSTRUCTION LIMITED
GGL 12” X 50KM GAS PIPELINE PROJECT
GAUGE PLATE PHOTOGRAPHIC RECORD
S/N
PHOTOGRAPH
DESCRIPTION
PHOTOGRAPH NO
PHOTOGRAPH
DATE
GAUGE PLATE
DIAMETER/
THICKNESS
REMARK