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

Page 2 of 38

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.


Page 3 of 38

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


Page 7 of 38

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


Page 16 of 38

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.


Page 22 of 38

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


Page 23 of 38

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.


Page 24 of 38

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


Page 25 of 38

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


Page 26 of 38

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

Fig 2.7 vibrational analysis process and

graph


Page 27 of 38

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.


Page 28 of 38

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


Page 29 of 38

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


Page 30 of 38

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


Page 31 of 38

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.


Page 32 of 38

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


Page 33 of 38

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.

Fig2.10 ER probe circuit


Page 34 of 38

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


Page 35 of 38

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


Page 36 of 38

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


Page 37 of 38

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)


Page 38 of 38

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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