Aqib Rasheed Internship Report1

Submitted To: Imtiaz Ali Shah
HEAD CM&I at MOL Pakistan Oil & Gas Co. B.V.
Submitted BY: AQIB RASHEED
Internship Report 2016
Ghulam Ishaq Khan Institute of
Engineering Sciences & Technology

INTERNSHIP REPORT 2016
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ACKNOWLEDGEMENTS:
Above all else, I thank to Allah Almighty for giving me such a commendable
learning opportunity in the direction of exceptionally corporative and master
people at MOL Pakistan.
I might want to expresses gratitude toward Mr. Imtiaz Ali shah for esteeming me
to work here in MOL Pakistan. I value the administrators of CPF for their direction
about the procedure. Being a Material engineer, I invested a ton of energy in
condition observing and the different operations on which MOL is working there .
I might want to say an exceptional thank to CM&I Section Head Mr. Imtiaz Ali
Shah for their bolster, consolation, direction and permitting me to partake each
movement of CM&I office all through the temporary job time frame. Further I
might want to say thanks to Mr. Bilal Hamid and Farhan Anjum who attempted to
show me everything best of his insight and exertion. To wrap things up, I might
want to acknowledge of Mr. Shabir Ahmad Khan, Zohaib Ahmad, Zahid Usman
who shared his encounters and showed me best to his exertion. Finally, I might
want to thank all MOL Employees for their corporative conduct and direction
about industry.

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Table of content:
1 ACKNOWLEDGEMENTS …………………………………………………………..2
2 ABSTRACT………………………………………………….…………………………….4
3 INTRODUCTION……………………………………………………………………….5
4 WELL HEAD AND VALVE ASSEMBLIES …….……………………………… 6
4.1 Christmas tree ………………………………………………………………………6
4.2 Choke manifold……………………………………………………………………..7
5 CORROSION INHIBITORS ………………………………………………………….7
6 Valve assembly ………………………………………………………………………..8
7 PROCESS CPF …………………………………………………………………………..9
8 Phase Separation ……………………………………………………………………10
9 GAS PROCESSING……………………………………………………………………12
10 CONDENSATE PROCESSING…………………………………………………..16
11 WATER PROCESSING …………………………………………………………..17
12 CONDITION MONITORING & INSPECTION……………………………20
12.1 Cathodic protection……………………………………………………………21
13 TESTS FOR CORROSION MONITORING…………………………………24
14 Die penetrant test ……………………………………………………………...35
15 Vibration Analysis ……………………………………………………………….38

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ABSTRACT:
My internship began from procedure of CPF, where I acquire brief procedure
portrayal of gas, condensate and water. We did different survey techniques for
corrosion monitoring of pipe line at CPF and some well heads. As we were in
CM&I Department which is related to my core subject Material Engineering. I
learnt about Cathodic protection framework establishment for pipelines, soil
resistivity, and pipe to soil potential survey. Vibration analysis of machines at CPF
and thickness meter for all intents and purposes performed on wellheads and
particular zones of plant. Most of thickness survey we did was at (Makori 1) which
has been unfunctional since 2 years and there were about 1200 points to be
measure. I also did DCVG survey of fire water pipe line at CPF.

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INTRODUCTION:
MOL, the main Hungarian Oil and Gas Exploration and Production Company has
been working in Pakistan through its backup MOL Pakistan Oil and gas Company
B.V. in various joint endeavors since April 1999. TAL is a joint endeavor of MOL,
PPL, OGDCL, POL and GHPL, MOL is the administrator in this joint endeavor.
There are four repositories of MOL Pakistan from where food is coming Makori
East, Maramzai, Manzalai, and Mamikhel . Mardan khil has been installed but not
yet started. An extremely fascinating reality of MOL Pakistan repositories is that
liquid of all stores is sweet. For the most part in oil industry, repositories are
harsh. Sharp supplies are those, which contains H2S. Diverse quantities of wells
are working in every store. The feed from all supplies is gathered in valve
assemblies. This feed from valve congregations is forward to the handling offices.
CPF (Central Processing Facility) is an office of creation of gas, condensate and
water. The primary procedure happens in the CPF is division of liquid into gas,
condensate, and water. Optional procedure of gas is to accomplish the detail of
SNGPL to offer this gas. These particulars are HCDP (hydrocarbon dew point) and
Moisture content. Condensate is handled to control Reid Vapor Pressure
underneath 7psi. This condensate is put away into the barrels and offers in barrels
to refineries and transported in bowsers. Water is prepared to lessen the effect of
this water on the earth. Water is prepared to evacuate the ensnared gasses and
oil content. This water is put away in vanishing lakes for dissipation. Presently
CM&I division presented another marvel in handling of delivered water is its
cleansing by Reverse Osmosis.
Condition Monitoring and Inspection office in MOL Pakistan is taking a shot at the
erosion insurance of wellheads, pipelines, and capacity tanks.

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WELL HEAD AND VALVE ASSEMBLIES:
A wellhead is the component at the
surface of an oil or gas well that
provides the structural and
pressure-containing interface for
the drilling and production
equipment
Different components of well
head are:
CHRISTMAS TREE:
Christmas tree has tree type structure with valves arranged on it.
Different valves on Christmas tree.
Sub Surface Safety Valve
(SSSV)
 Surface safety Valve
(SSV)
 Master valve
 Kill wing valve
 Swab valve
 Production valve

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CHOKE MANIFOLD:
Choke manifold is used to
drop the pressure of the
gas and condensate
coming from the well.
Types are
 Fixed choke (Keeps
constant flow)
 Auto choke( can be
adjusted according to
requirement)
CORROSION INHIBITOR INJECTION:
These are injected at upstream choke vale to prevent corrosion in the flow pipe
line.
METHANOL INJECTION PACKAGE:
Due to a great pressure drop in the choke manifold, hydrates are formed in the
lines. Hydrate crystals restrict gas flow. Hydrates can plug
Valves, meters, instruments, and flow lines upsetting or even shutting down
processes. Therefore Methanol is injected upstream of choke valves and is
circulated in the gas lines to inhibit hydrate formation. Methanol decreases the
freezing temperature of hydrates hence the Crystal structure is broken and the
hydrates are removed from the gas lines.
Fig 1.3 Choke Manifold

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VALVE ASSEMBLIES:
Valve assemblies are where the flow pipelines from different wells are connected
so that their flow to the CPF can be more feasible. . A valve station gathers gas
from different nearby wellheads. Gathering details of these Valve Stations are
shown in following table.
Valve Assembly
Valve Assembly
Wellheads
VA-1 M-1,M-3
VA-2 M-5, M-6 and VA-1
VA-2A M-4 and VA-2
VA-3 M-2,M-7 and VA-2A

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PROCESS CPF:
The feed from Well heads and Valve assemblies is introduced into the
CPF where it undergoes a number of processes afore determinately
being dispatched to the felicitous companies.
At first phase disunion of victual takes place in which gas, condensate and water
are disunited
on the
substratum
of density
distinctions
between
them in slug
catcher.
After that
gas is routed to the Inlet separator and then to Gas Dehydration Unit where the
moisture contents are reduced from gas as per requisites of SNGPL.
This dehydrated gas is then routed to HCDP Unit where the hydrocarbon contents
of Gas are controlled as per requisites of SNGPL. This gas is then routed to Sales
Gas Booster Compressor and Metering Skid and is then determinately dispatched
to SNGPL.
Fig 1.5 CPF View

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SALES GAS SPECIFICATIONS
Water content Not more than 7 lb/MMSCFD
DEW POINT 32
CALORFIC VALUE Not less than 1000 BTU
PRESSURE More than SNGPL line
OXYGEN Not more than 1 %
NITROGEN Not more than 5 %
PHASE SEPARATION SYSTEM:
The feed from wellheads consists of an amalgamation of gas, condensate and
water. Consequently the primary step is the disseverment of this cumulation so
that each product is treated discretely according to their felicitous procedures.
SLUG CATCHER:
Feed (Gas, condensate, water) from wellheads and valve accumulating assemblies
are introduced to a finger type 3 phase Slug Catcher which is basically a 3-phase
disseverment unit. In slug catcher, the disseverment of the aliment occurs on the
substructure of density distinction between water, condensate and gas. The
concrete gravity of water is 1 while that of condensate is 0.76. Water being the
heaviest among the three subsides at bottom followed by condensate while gas
being the lightest elevates above. Gas is then alimented to the inlet separator and
dehydration unit for
further processing
while the condensate
is routed to
condensate
stabilization unit and
water is routed to
the engendered
Fig 1.6 slug catcher

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water treatment unit for further processing.
Slug catcher has
3 manifolds:
 Gas Manifold
 Condensate
Manifold
 Water
Manifold
INLET SEPARATOR:
Gas from slug catcher is divided into two streams which are routed to the inlet
separators of each train. The inlet separator is rudimental a long vertical pressure
vessel. It consists of a deflector plate, demister plate vertex plate. The purport of
deflector is to transmute/break the momentum of the incoming gas stream and
transmute its
direction. Due
to this, the
heavier
components
are not able to
flow with the
same
momentum as
the lighter
components
and thus they
are condensed
Fig 1.7 showing density base separation in slug
catcher
Fig 1.8 inlet separator

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while the gas elevates. The purport of the demister plate is to demist
the liquid droplets from the gas. These liquid droplets are coalesced and
they fall down due to gravity while gas is routed to the MRU (which is
not currently in accommodation) and thus the gas is bypassed to multi-
pass heat exchanger while the condensate is discharged to flash separator and
water is discharged to closed drain header on level control. Vertex breaker
prevent from whirlpool.
Design temperature and pressure for inlet separator is 150°F& 1785 psi
respectively.
GAS PROCESSING:
Gas processing facility consists of a number of units. These processes are working
to meat above given designations. These designations are obtained by fallowing
two points.
 Moisture content control
 HCDP (Hydrocarbon Dew Point) control
TEG CONTACT TOWER:
The water saturated natural gas flows directed to Multi-pass Exchanger.
 First pass when its temperature higher or identically tantamount to88°F, or
flow directly to the Tri-Ethylene Glycol (TEG) Dehydration Unit when its
temperature below 88o F. The saturated / 3-phases gas stream introduced to
lower section of a chimney type counter current type contactor. The lower
section of the contactor is an integrated Knock-out column where the
commixed liquid phases (water and HC condensate) are disunited and the
saturated gas flows upward through the chimney to the structured packing
section where the water moisture is abstracted by the down flowing TEG. Dry
gas exits the top of the Glycol Contactor and flows to the Gas/Glycol
Exchanger, where the dry gas stream cools the lean glycol stream afore it
enters the Contactor Tower.

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 The dry gas stream exits the Gas/Glycol Exchanger and flows to the
Multi-pass Exchanger (second pass) through a Coalescing Gas Filter to
abstract any carryover liquids. The down-flowing glycol solution becomes
“rich” or laden with water as it flows down the absorber tower.
Fig 1.9 TEG Unit process flow diagram

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HCDP (HYDROCARBON DEW POINT) CONTROL:
COLD SEPARATOR:
The gas stream leaving Multi-pass Exchanger (second pass) is then directed to
Cold Separator where fluid hydrocarbons separate out and level controlled
through Multi-pass Exchanger. This fluid is utilized to decrease the temperature of
approaching gasses and after that brought into Condensate adjustment unit. The
gas stream is coordinated to Low Temperature Separator (LTS) by means of JT -
valve.
Fig 1.10 Joule Thomson Effect

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LOW TEMPERATURE SEPARATOR:
The gas stream is further diminished in fluid substance in the Low
Temperature Separator (LTS) after weight lessening over the JT-Valve.
This will lessen the temperature of gas down to - 21 °F after weight setback. LTS
gas and fluid will go through the multi-stream heat exchanger to cool the bay
crude gas. Dew point decrease unit should be outlined in a manner that it might
be worked without Sales Gas Booster Compressor.
Sales GAS BOOSTER COMPRESSOR:
Treated gas from the two gas trains should be consolidated and a typical suction
header will bolster to responding sort Sales Gas Booster Compressor at a suction
weight of 980 psi to help the dew guided gas toward the wanted level of offers
gas weight of 1200 Psig. Compressors are gas motor driven.
Fig 1.11 Booster Compressors

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CONDENSATE PROCESSING:
Condensate from slug catcher enters into flash separator.
Follow chart showing condensate flow line.
FLASH SEPARATOR:
Condensate from the Slug Catcher, Inlet Separator, Integrated KO TEG area, Cold
Separator and Low Temperature Separator is consolidated in a header directed to
the Flash Separator to streak off the broke down gasses in the fluid. Flashed
Fig 1.12 Condensate flow line

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gasses is reused by means of Flash gas Compressor to help the weight to
coordinate the primary procedure Raw Gas at plant bay weight (at the
outlet of Inlet Separator and before first go of Multi-Phase Exchanger).
CONDENSATE STABILIZATION COLUMN:
Condensate from the Flash Separator should go through Feed/Bottom Exchangers
to be warmed up to 215 °F before being brought into Condensate Stabilizer
Columns (working weight = 50 psig). Off gasses from the Condensate Stabilizers
might be steered to individual Flash Separator by means of Condensate Overhead
Compressors. Balanced out condensate might be sent to Condensate Storage
Tanks in the wake of losing its warmth to condensate nourish in the Feed/Bottom
Exchangers and Product Air Cooler down to 120 °F.
WATER PROCESSING:
Water processing consists of 3 facility treatment:
 Water Degassing Boot
 Corrugate Plate Interceptor (CPI) Separators
 Evaporation Ponds
WATER DEGASSING BOOT:
The water degasser is a vertical two stage separator. Water degassing boot is
utilized to separate water gas and condensate from the water.
CORRUGATE PLATE INTERCEPTOR (CPI) SEPARATORS:
CPI separator is a rectangular chamber having a weir plate to make fundamental
chamber for incomplete detachment and folded plate capture attempt. Its
motivation is to separate water and condensate.

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EVAPORATION PONDS:
Evaporation ponds are fundamentally built to vanish the undesirable tainted
Produced Water. Liners (High Density Polyethylene HCDP's) additionally called
Geo-Membranes are introduced at the base to keep water from leakage, so to
shield the area
from this acidic
water.
Fig 1.13 CPI Process
Fig 1.14 Produced Water pond

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PFD OF CPF

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CONDITION MONITORING & INSPECTION:
The division is concerned with standard checking of pivoting and stationary
equipment of the plant. The most imperative duty is the support of the CP System
of MOL Pakistan and doing related reviews and guaranteeing that all pipelines,
beginning from wellhead and including all the channeling and hardware of the
plant, are very much ensured against Corrosion and are inside the Corrosion
Tolerance in ordinary working conditions.
The functions CM&I performing are listed below.
 Cathodic protection
 Soil Resistivity
 E log I survey
 Installation of CP system
 Stray Current
 Interference Current
Corrosion Monitoring
 ER Probes
 Corrosion Coupons
 Pipe to soil potential
 Thickness
 DCVG survey
 Vibration analysis of Rotary Equipment’s
 Reverse Osmosis Plant
Cracks monitoring tests
 Dye Penetrant Testing (DPT)
 Magnetic Particle Testing (MPT)
 Thermography Survey

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Cathodic protection:
Cathodic Protection (CP) is a strategy used to control the consumption of a metal
surface by making it the cathode of an electrochemical cell. A straightforward
strategy for security associates ensured metal to an all the more effortlessly
consumed "conciliatory metal" to go about as the anode. The conciliatory metal
then erodes rather than the ensured metal. For structures, for example, long
pipelines, where latent galvanic Cathodic assurance is not satisfactory, an outer
DC electrical force source is utilized to give adequate current. Cathodic assurance
frameworks secure an extensive variety of metallic structures in different
situations. Regular applications are: steel water or fuel pipelines and capacity
tanks, for example, home water radiators; steel docks heaps; ship and watercraft
frames; seaward oil stages and coastal oil well housings; and metal support bars
in solid structures and structures. Another regular application is in excited steel, in
which a conciliatory covering of zinc on steel parts shields them from rust.
Cathodic protection can, in some cases, prevent stress corrosion cracking.
Cathodic protection (CP) is the worldwide practiced method for corrosion
protection. The structure to be protected is made cathode. There are two
methods of CP.
 Galvanic Coupling
 Impressed Current
GALVANIC COUPLING:
In this method, the structure to be provided is electrically connected with another
metal whose native potential is more active or which is anodic in galvanic series
w.r.t the structure. Now, in this corrosion loop our structure will become cathode
and will be protected. The anodic metal will corrode protecting our structure.

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IMPRESSED CURRENT:
In submerged structures current requirements are high due to high resistivity of
soil and structure. So we use an external power source for protection. Unlike
galvanic coupling here anodes are inert and noble e.g. Mix Metal Oxide (MMO),
platinum and graphite etc. NACE states three criteria for protection of submerged
ferrous structures.
Fig 2.1 Galvanic process to prevent pipe
from corrosion

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 A Cathodic potential of at least 0.85 V and at most 1.2 V with
Cathodic protection applied. IR drop along the current path should be
excluded from this value.
 Instant off polarized potential should not be less than 0.85 V. This off potential
helps to find the IR drop along the current path
 A minimum of 100 mV of Cathodic Polarization between the structure surface
and a stable reference electrode contacting the electrolyte. The formation or
decay of polarization can be measured to satisfy this criterion.
OVER PROTECTION:
If our protection potential goes beyond 1.2 V than this condition is called
overprotection and it is not recommended practice. If protection potential is
more than 1.2 V then Cathodic disbondment of the coating will occur. As a result
H2 gas will start to form and release.

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SOIL RESISTIVITY:
Soil resistivity survey is done in order to find the current required for
protection potential.‘Wenner four pin’ method is used to determine the
soil resistivity.
TESTS FOR CORROSION MONITORING:
 ULTRASONIC THICKNESS SURVEY:
Ultrasonic testing (UT) is a family of non-destructive testing techniques based on
the propagation of ultrasonic waves in the object or material tested.
Principal:
The essential target of this overview is to distinguish any consumption which may
have occurred amid operation of any vessel, tank or pipe and improve the C.I
infusion rates. The study is likewise done to watch any unusual misfortune in
thickness. The information is contrasted with deference with standard
estimations of Corrosion rate and MAWP acquired at the charging of the plant.
The overview is completed by reference focuses set apart in an isometric drawing
of the structure
Methodology:
We did thickness survey on pipes
at Makori 1 CPF which is shutdown
since 2 years. Every one of these
areas, called Thickness
Measurement Location (TML),
comprises of four focuses set apart
at 90 degrees from each other on
the perimeter of the funnel in a
clockwise course. If there should
arise an occurrence of a pipe
likewise, the four focuses are set Fig 2.3 Ultrasonic testing using
probe and collecting data

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apart around the vessel, one each in North, South, East and West
heading of the pipe. Thickness diminishment rate is ascertained by
making examination with perusing got from past studies. The survey
focuses on the comparative analysis of MAWP with design pressure.
Types of scan:
A scan: It’s basically energy vs time graph on display of UT Meter
B scan: profile view and time vs scan distance
Fig 2.4 A-scan graph
Fig 2.5 B-Scan view

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C scan: planar view gives top view of surface
DCVG COATING DEFECT SURVEY:
DCVG stands for Direct Current Voltage Gradient and is a survey
technique used for assessing the effectiveness of corrosion protection on
buried steel structures.
Principle of survey:
This review procedure uses a dc current (either the inspired current CP
framework or an impermanent framework) which is beat by method for a present
interrupter. Current course through the dirt causes voltage angle at covering
deserts that are distinguished utilizing two earth contact tests and measured
utilizing a voltmeter. The voltmeter consolidated in the review hardware is a
delicate; focus zero instrument permitting area of imperfection to be controlled
by relative area of the tests and extremity of the perusing.
Fig 2.6 C-Scan planar view

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Site equipment:
High affectability focuses zero voltmeter. Current Interrupter
(appropriate for current to be hindered and with an exchanging speed perfect
with the review meter). Reference (Ski) tests well with the study meter. Transitory
dc current source and ground bed hardware (required if pipeline not secured by
inspired current or framework can't be intruded).
METHODOLOGY:
Before beginning of any review segment a present interrupter is introduced in the
closest existing Cathodic security station or impermanent current source which
might be set up as vital. Normally, a base potential swing of 500-600 mV is looked
for and the present source yield is balanced as needs be. The utilization of a beat
current empowers covering imperfections to be recognized from stray footing
Furthermore, earthly streams. The distinction amongst "on" and "off" possibilities
is recorded at the test point closest the review begin point, and all other test
focuses experienced, and the study initiated. The administrator navigates the
pipeline course utilizing the tests as strolling sticks. One test is in contact with the
ground at all times and for a brief length between steps both tests must be in
ground contact. One test can be on the centerline of the pipeline and the other
kept up at a horizontal detachment of 1-2 m or tests can jump frog along the
inside line. On the off chance that no deformities are available the needle on the
voltmeter enrolls no development.
As an imperfection is drawn closer a perceptible change is seen on the voltmeter
at a rate like the intrusion cycle. The plentyfulness of the variance increments as
the imperfection is drawn nearer and modification of voltmeter affectability is
made as fundamental.

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Defects which can be find through DCVG:
 Locate Coating Defects
 Defect Size
 Reduction in Protection
 Priority for Refurbishment
 Continued Coating Deterioration
Fig2.7 DCVG survey to locate defects

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PIPE TO SOIL POTENTIAL:
A potential survey is a technique used to measure the magnitude of corrosion of
pipelines and detect hot spots where the occurrence of corrosion is severe.
Principal of survey:
The potential survey is based on recording pipe-to-soil potentials at regular
intervals over the pipeline with the reference electrode(s) located on the ground
surface. The higher the value of pipe-to-soil potential, the higher the magnitude
of corrosion. The structure-to-soil potentials do not give a qualitative
measurement of corrosion. However, they are very useful in the prediction of
corrosion when used in conjunction with other data, such as soil resistivity.
SCOPE:
This section covers the following:
 Appropriate pipe to soil readings.
 Testing copper-copper sulfite Half Cell.
 Appropriate method of taking pipe to soil readings.
 IR Drop/Millivolt Shift.
PIPE TO SOIL SURVEY METHODOLOGY:
 Pipe-to-Soils readings shall be taken anytime that buried or submerged pipe
coating is exposed:
 Coating is removed or damaged.
 Not required when vacuum excavated.
 Adequate Cathodic Protection:
 The level of Cathodic protection shall be considered adequate when the

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minimum pipe to soil potential is at least a -0.85 volts (Negative 850
millivolts) for metallic pipelines. This is the level at which metallic
pipe no longer corrodes.
 A 100 millivolt shift is accomplished after the CP has been turned off
(may require 2minutes to 24 hours)
 Inadequate Cathodic Protection:
 Reading less than – 0.85 volts (more positive than) may indicate inadequate
CP requiring medial action to correct the situation
 Excessive Cathodic Protection:
 The amount of Cathodic protection must be controlled so as not to damage
the protective coating or the pipe. This is accomplished by limiting the
maximum “on” pipe-to soil potential to negative (-) 2.5 volts.
 Any reading greater than - 2.5 volts, indicates excessive CP requiring remedial
action to correct the situation. E. CP records shall be maintained for no less
than 5 years. It is recommended that these CP records be maintained for the
life of the pipeline.
Fig 2.8 PSP process overview

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TESTING HALF CELLS:
Prior to taking any pipe to soils readings it is important to check or
calibrate the reference. The test is simply to place the porous plugs of a
standard (unused) electrode and the field electrodes end to end and measure the
millivolt difference. Generally, if the difference is less than 4 to 6millivolts, no
maintenance of the electrodes will be required.
Testing of the field reference electrodes should be undertaken each morning prior
to the start of the survey. The millivolt difference and polarity between the
working electrodes and the standard should be recorded.
IR DROP:
IR DROP / IR ERROR
 IR drop is a product of current and resistance. (Voltage drop) Voltage drop is
negligible in the measuring circuit under the following conditions:
• Metallic path lengths are short.
• Good contact between reference cell and electrolyte (moist soil).
• Good connection points (clean metal to metal contact).
• High-input impedance meter is used.
• Resistivity is low.
 All the voltage drops in the measuring circuit are controllable except for the
Drop across the electrolyte (surrounding soil or other medium). To reduce the
IR drop.
• Place the electrode near the structure coating holiday.
• Or, interrupt the current flow.
• Calculations can also be made to subtract the IR drop.

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 When current is interrupted, the potential should be measured at
“instant off “which refers to the potential after IR drop is eliminated
but before polarization begins to dissipate.
Fig2.9 IR drop due to soil resistivity

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ELECTRRICAL RESISITANCE (ER) MONITORING:
The electrical resistance (ER) technique is an "on-line" method of
monitoring the rate of corrosion and the extent of total metal loss for
any metallic equipment or structure. The ER technique measures the effects of
both the electrochemical and the mechanical components of corrosion such as
erosion or cavitation. It is the only on-line, instrumented technique applicable to
virtually all types of corrosive environments.
PRINCIPALE OF OPERATION:
The electrical resistance of a metal or alloy element is given by:
Where:
L = Element length
A = Cross sectional area
r = Specific resistance
Reduction (metal loss) in the element's cross section due to corrosion will be
accompanied by a proportionate increase in the element's electrical resistance.

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ER SENSING ELEMENTS:
Sensing elements are available in a variety of geometric configurations,
thicknesses, and alloy materials. Linear polarization resistance (rosion probes are
commonly used in the water treating industry and other environments where
instantaneous, on-line corrosion rate readings are required. Linear polarization
probes are ideally suited to monitor fluctuations that may occur within a system;
for example, these probes can be used to monitor corrosion inhibitor effects on a
regular basis.
Fig 2.10 ER Probe Circuit

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DIE PENETRANT TEST:
Liquid penetrant exams check for material flaws open to the surface by flowing
very thin liquid into the flaw and then drawing the liquid out with a chalk-like
developer.
PRINCIPAL OF TEST:
The Penetrant may be applied to all non-ferrous materials and ferrous materials,
but for inspection of ferrous components magnetic-particle inspection may be
Fig 2.11 different type of Probe

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preferred for it subsurface detection capability. Commonly, DPI is used
to detect cracks, surface porosity, lack of penetration in welds and
defects resulting from in-service conditions (e.g. fatigue cracks of
components or welds) in castings, forgings, and welding surface defects.
The basic steps are:
 Clean the part
 Apply the Penetrant and allow dwelling
 Remove excess Penetrant.
 Apply a developer and allow developing
 Read the part for indications.
 Clean the part
Fig2.12 steps of DPT

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Fig1: (Section with a normally not visible surface-breaking crack)
Fig2: (Penetrant is applied to the surface)
Fig3: (Excess Penetrant is removed)
Fig4: (Developer is applied, rendering the crack visible)

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VIBRATION ANALYSIS:
Vibration Analysis (VA), applied in an industrial or maintenance
environment aims to reduce maintenance costs and equipment downtime by
detecting equipment faults. VA is a key component of a Condition Monitoring
(CM) program, and is often referred to as Predictive Maintenance (PdM).
Purpose:
This test is carried out to find out the working condition of the rotary equipment
Methodology:
The entire CPF office is isolated into various regions and further turning gear are
recognized and encouraged into the machine. The test is completed division savvy
as it were. Readings are taken at the inboard and detachable of engines and
pumps. The test is joined in three distinctive courses at every area: on a level
plane, vertically and pivotally.
Fig 2.13 vibrational analysis process and
graph

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