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King Fahd University of Petroleum & Minerals College of Engineering Sciences
Mechanical Engineering Department
Coop Training Program
“Yanbu Aramco Sinopec Refining Company”
Final Report
(Construction Activities of Newly Installed Mechanical Equipment)
Submitted to
Coop Advisor: Abdelaziz Bazoune
Coop Coordinator: Mohammed Antar
Prepared by:
Name Family Name First Name
Mohammed Galal
KFUPM ID#: 2 0 0 9 9 3 6 9 0
Submission Date:
(dd) (mm) (yyyy)
2 1 0 9 2 0 1 4
Summary
The report describes the knowledge and experience gained during the twenty eight weeks
of training at YASREF. Because the training was at an under construction company, the
report will mainly focus on some of the construction activities. These construction activities
can be related to plant piping construction such as pressure testing, pipes’ flange bolt
tightening and post weld heat treatment of some welding joint. They can be related to
rotating equipment such as pump alignment and motor solo run. Moreover, construction
activities can be related to other equipment such as the process of belt splicing in belt
conveyor system. Each of these construction activities encountered during the training has
been described in details with some photos and referring to some standards. At the end of
the report, three case studies have been discussed. The first one is a designed base case
study. The second and third case studies are related to problems faced during the
construction activities.
Acknowledgment
First of all, I would like to express my thanks to Allah for his guidance and support during my
whole training period. All praise to Allah that the training period went smoothly with a great
gained experience. A special thank is also goes to my parents who always stand beside me,
support me and pray for me.
Secondly, I would like to thank both the mechanical engineering department and the
training department for their collaboration to run this program successfully. Thank you for
your hard work to contact with many companies to offer training opportunities for students.
In my case, I got my training opportunity through the training department website.
Moreover, I would like to express my deep thanks to the COOP coordinator and my COOP
advisor Dr. Abdelaziz Bazoune who organize all related COOP issues in the department.
Thank you for your support and help during my training period.
Finally, I would like to express my great appreciation to the host company (YASREF) and the
project quality management department in which I have been assigned. A special thank
goes to my supervisor, Mr. Talal Mahjoub, who organized my rotation schedule in the
different packages of the project. Thank you to all quality engineers who I work with them.
1
Table of Content
Introduction ..................................................................................................................... 4
YASREF Overview ................................................................................................................... 4
Assigned Department and COOP Work Plan ......................................................................... 4
Pressure Testing of Plant Piping ........................................................................................ 6
Hydrostatic Test ..................................................................................................................... 6
Pneumatic Test .................................................................................................................... 10
Post Weld Heat Treatment of Pipes ................................................................................ 11
Flange Bolt Tightening .................................................................................................... 14
Pump Alignment ............................................................................................................. 16
Fabric Belt Splicing ......................................................................................................... 21
Case Studies ................................................................................................................... 26
Case Study (1) ...................................................................................................................... 26
Case Study (2) ...................................................................................................................... 29
Case Study (3) ...................................................................................................................... 30
Conclusion and Recommendation ................................................................................... 33
References ..................................................................................................................... 34
2
List of Figures
Figure 1: Hydrostatic Test Equipment .................................................................................................... 6
Figure 2: HAZ of Welding Process ......................................................................................................... 11
Figure 3: PWHT Equipment ................................................................................................................... 11
Figure 4: Sample PWHT Report ............................................................................................................. 13
Figure 5 : Tightening Sequence of 24 Bolts and Bolt Numbering for Large Number of Bolts (36-68) .. 15
Figure 6: Offset Misalignment .............................................................................................................. 16
Figure 7: Angular Misalignment ............................................................................................................ 16
Figure 8: Manufacturer Pump Information .......................................................................................... 16
Figure 9 : Potable Water Booster Pump General arrangement drawing ............................................. 17
Figure 10: Alignment Tools ................................................................................................................... 17
Figure 11: Alignment Bracket with Two Dial Indicators ........................................................................ 19
Figure 12: Tightening and Soft Foot Check of Motor ............................................................................ 19
Figure 13: Alignment Report ................................................................................................................. 20
Figure 14 : Final Alignment Steps .......................................................................................................... 21
Figure 15: Belt Conveyor ....................................................................................................................... 22
Figure 16: Belt Splicing Equipment (1) .................................................................................................. 22
Figure 17: Belt Splicing Equipment (2) .................................................................................................. 23
Figure 18: Cutting Belt Ends .................................................................................................................. 23
Figure 19: Belt Marking ......................................................................................................................... 24
Figure 20: Cover Fill in Cut and Removing Rubber Cover ..................................................................... 24
Figure 21: Final Look of Belt Ends after Cutting .................................................................................... 24
Figure 22: Cleaning and Grinding .......................................................................................................... 24
Figure 23: Installing Vulcanizing Press Machine on Belt ....................................................................... 25
Figure 24: Belt Ends after Splicing ........................................................................................................ 25
Figure 25: Effects of Insulation and Heating on Heat transfer ............................................................. 26
Figure 26: Skin Effect Electrical Heat Tracing ........................................................................................ 27
Figure 27: Electrical Heat Tracing of Sulfur Feed Drum ........................................................................ 27
Figure 28: Hot Oil Jacketed Pipes .......................................................................................................... 28
Figure 29: Hot Oil System ...................................................................................................................... 28
Figure 30: Temporary Support on Pipe ................................................................................................. 29
Figure 31: Motor Solo Run .................................................................................................................... 30
Figure 32: Vibration spectra .................................................................................................................. 32
3
List of Tables
Table 1 : COOP Rotation Schedule ............................................................................................. 5
Table 2: Line Designation Table ................................................................................................. 7
Table 3: Requirements for PWHT ............................................................................................ 12
Table 4: Torque Values for Bolt Tightening ............................................................................. 14
Table 5: Bolt Tightening Sequence for 36 Bolts flange ............................................................ 15
Table 6: Example for Standard Tables of Belt Splicing............................................................. 23
Table 7 : Vibration Readings of Motor Solo Run at Different Condition ................................. 31
List of Abbreviations and Symbols
YASREF: Yanbu Aramco Sinopec Refining Company
KBR: Kellogg, Brown and Root, an American Engineering and Construction Company
PQMD: Project Quality Management Division
bpd: Barrel per Day
LPG: Liquefied Petroleum Gases
PWHT: Post Weld Heat Treatment
NDT: Non Destructive Testing
ASME: American Society of Mechanical Engineers
SAES: Saudi Aramco Engineering Standards
SAEP: Saudi Aramco Engineering Procedure
Ppm: Parts Per Million
DBSE: Distance between Shaft Ends
RFI: Request for Inspection
4
Introduction
YASREF Overview
YASREF stand for Yanbu Aramco Sinopec Refining Company. It is a joint project between
Saudi Aramco and China petrochemical company (Sinopec). Saudi Aramco is one of the
leading companies in oil and gas industry in the world having 62.5 % equity share in the
company. On the other hand, Sinopec is one of the biggest companies in petrochemical
products in china having 37.5 % equity share in the company. The refinery is located in
Yanbu Industrial City on the red sea. The refinery total area is 5.2 million square meters
with a capacity to refine a 400,000 barrel per day (bpd) of Arabian heavy crude oil into final
products for export and domestic use. These products include:
Gasoline
High Quality Diesel
Liquefied Petroleum Gases (LPG)
By Product Sulfur
Petroleum Coke for Export
The agreement between Aramco and Sinopec was in May 2006. After agreement, KBR
Company with other design companies was selected for the design of the refinery. In July
2006, the design companies started the design phase of the company. In April 2009, the
construction of the refinery started and it is still ongoing. The construction of the refinery is
divided into eighteen packages with eighteen main contracts. It is expected that test runs
for the refinery to be conducted on September 2014 and the first refined products to be
exported by November 2014.
Assigned Department and COOP Work Plan
At YSREF Company, I have been assigned in the project quality management department. At
this division, the main objective of their work is to monitor all construction activities done
by contractors and ensure that the work is complying with YASREF standards. Construction
activities include piping, mechanical equipment, welding and NDT. During my training, I
have been working with a group of Mechanical engineer inspectors. As a mechanical
inspector at YASREF, You have to be familiar with the standards governing the construction
activities. It is also important that your relationship with contractor’s engineers and stuffs
does not affect your duties. What is correct and agree with standards should be accepted
and what is wrong or not complying with standards should be rejected. At the company, Mr.
Talal Mahjoub, PQMD manger, was assigned to be our main mentor during our training
program. He developed a training program for us that include the following schedule.
5
Table 1 : COOP Rotation Schedule
Training Period
Department Name
(Package)
Tasks:
Please indicate if individual work
assignments or team assignments
will be made Wee
k #
From
(DD/MM/YYYY)
To
(DD/MM/YYYY)
1-2 26/01/2014 06/02/2014
Quality Division
Lectures on :
1. Safety
2. Overview about the
company
3. Quality
3-6 09/02/2014 06/03/2014
Tank Farm
Interconnecting System
Tasks will be assigned
based on available work
during the assigned period.
The tasks will be assigned
according to the listed
objectives.
7-11 09/03/2014 10/04/2014
Delayed Coker Unit
12-17 13/04/2014 22/05/2014
Solid Handling
18-23 25/05/2014 03/07/2014 Gasoline
24-28 06/07/2014 07/08/2014 Hydrocracker
6
Pressure Testing of Plant Piping
After completion of all construction activities of pipes such as welding, mechanical
assembly, post weld heat treatment and non-destructive testing, pipes are subjected to
pressure testing to check that they will withstand the actual pressure and there is no
leakage. The most commonly performed pressure tests are hydrostatic and pneumatic.
1) Hydrostatic Test
Definition
It is the type of pressure test in which the pipe to be tested is pressurized using water.
Reference Standards Used at YASREF
As for any engineering work, hydrostatic test follows some standards for the correct and
safe procedure. For hydrostatic testing at YASREF, the main reference standards are:
International standard
ASME B31.3
Project specifications:
(SAES-L-150/SAES-L-
350/SAES-A-004/SAES-
A-
007/SAEP327/GI0002.
102)
Equipment and Calibration
1) Pump
2) Manifold
3) Two pressure gauges
4) Relief valve
5) Water
6) Blind flanges
7) Pipe to be tested
The test equipment must be calibrated or the calibration is still valid before the test. The
calibration certificate should be checked and compared with the one labeled on the test
equipment.
a) Pressure gauges should be calibrated monthly. Test pressure should be within
30% to 80 % of the reading ranges of these pressure gauges.
b) Relief valve should be calibrated weekly. It is set to depressurize the system in
case the test pressure exceeded 5 % of the required test pressure.
c) Manifold should be calibrated each six months.
Figure 1: Hydrostatic Test Equipment
7
Hydrostatic Test Pressure Calculation
Based on ASME B31.3, minimum hydrostatic test pressure can be calculated with the
following formula:
Pt =
Where:
Pt: Minimum hydrostatic test pressure
P: Design pressure
St: Allowable stress at test temperature
S: Allowable stress at design temperature
Also based on ASME B31.3, maximum hydrostatic test pressure is calculated using
the following formula:
Pm =
Where:
Pm: Maximum hydrostatic test pressure
S: Minimum yield strength at test temperature
E: Quality factor
t: Pipe wall thickness minus mill tolerance
D: Outside diameter
At YASREF project, the hydrostatic test pressure is indicated on the line designation
tables of the isometric drawing of the pipelines. This table indicates also the design
pressure, design temperature and insulation requirements.
Table 2: Line Designation Table
8
Water Quality Used for Hydrostatic Test
The quality of water to be used for the test will vary based on the material of the pipe to be
tested or the actual fluid to be processed inside the pipe. The following points summarizes
the quality of water to be used in hydrostatic test.
For carbon steel piping, fresh water that is free of contaminant and with chloride
content less 300 ppm.
For low alloy, austenitic stainless steel and nickel alloy steel piping, water to be used
should have low chloride content ( less than 50 ppm)
Potable water and utility water piping should be tested with potable water.
Sea water is not allowed to be used as a test medium unless approved by Aramco.
Hydrostatic Test Pressure Duration
It is the time required to keep the piping system under the test pressure then inspection is
carried on. The following points summarizes the duration time of hydrostatic test pressure.
For plant piping, at least half hour is required prior to inspection
For pipelines, 26 hours is the required test duration
For firewater pipes, four hours is the minimum test duration.
Factors Affecting on Hydrostatic Test Pressure Value
While performing hydrostatic test, inspectors and technicians should be aware of the
factors that affect on the hydrostatic test value. The main two factors affecting hydrostatic
test value are:
1) Temperature
Temperature is directly proportional to pressure. When temperature increase the test
pressure will increase and when temperature drop the test pressure will drop. To avoid such
problem, conducting test pressure should be carried during day time of almost constant
temperature. If this is not applicable, depressurizing and pressurizing should be carried to
avoid temperature increase or decrease
2) Elevation
Calculation of hydrostatic test pressure does not take into account the elevation of pipes
above ground. This should be done by the hydrostatic test performer and inspector. One
rule of thumb is to increase the calculated hydrostatic test pressure by one bar for each ten
meter aboveground pipes.
9
Hydrostatic Test Pressure Steps
1) All welding, assembling, PWHT and NDT activities must be completed and checked as
per isometric drawing. Moreover, equipment that should not be included in the
hydrostatic test such as control and check valve must be removed from the line to be
tested.
2) The line to be tested must be cleaned from any foreign material. Cleanness of the
line can be achieved using compressed air.
3) Start filling the line with water from low point with the vents are open so that air will
not be trapped inside. When air is get trapped that would affect on pressure gauges
readings.
4) After removal of air inside the pipe, close all vents and pressurize the pipe with
water. Pressure should be increase with an increment of 25% of the desired test
pressure. At each increment allow some time for inspection. In case of any leak
detection, depressurize the system and solve the leak problem and retest the
system.
5) When the pressure on the pipe reach the desired test pressure, stop water pumping
and hold the test pressure for sufficient time as indicated on the test duration
paragraph.
6) Inspectors should carry on inspection for the system by one of the methods:
Visual inspection method
This method is used for plant piping in which half an hour is required for holding the test
pressure. In this method, inspector checks all weld and connections visually.
Pressure drop method
This method is used for pipelines that require more holding time. For inspection, inspectors
record the test pressure when it reach the desired test pressure and then check at the end
of the holding time. If there is a pressure drop, that is an indication of leakage.
7) Upon completion of the test, depressurize the system gradually.
Safety Requirements
1) All people involved in the test preparation and inspection must be wearing personal
protective equipment.
2) Test equipment must be positioned in a safe manner.
3) There should be warning signs closing the whole area that is under test.
4) No work is allowed for pipes that are included in the test.
5) If leakage is detected, depressurize the system to zero pressure then check the
leakage reason. No flange tightening is allowed while the system under pressure.
11
2) Pneumatic Test
It is the type of pressure testing in which the test medium is air. All specifications discussed
in hydrostatic testing applied to pneumatic test with few differences. These differences are:
Instead of pump, air compressor will be used.
Pt =
Air used for testing does not have to meet specific quality measurement such
the one that must meet the water used in hydrostatic testing.
The time needed to keep the test pressure prior to inspection is ten minutes.
No need for vents because the test medium is air.
Inspection for leaks in the system is carried on using a solution and checking
for bubbles.
No lay up is needed
Special safety requirement is needed when conducting pneumatic testing.
11
Post Weld Heat Treatment of Pipes
As the name of the process implies, it is a heat treatment process that is performed upon
completion of welding on the welding area and the heat affected zone. This heat treatment
removes the residual stresses developed during welding and recovers the microstructure of
the original metal. This process starts with heating the welding area up to a specific
temperature then holding that temperature for a specific time and finally cooling. The
heating and cooling rates as well as the temperature at which heating is hold for a specific
time should follow the recommended standards and practice.
PWHT Equipment
The main equipment for PWHT is:
1) Power source
2) Recorder ( Temperature and Current)
3) Ceramic pad heater
4) Insulation
Figure 3: PWHT Equipment
Figure 2: HAZ of Welding Process
12
When PWHT Is Required for Pipes
PWHT in pipes is governed by two factors:
1) PWHT required by the thickness of the pipe to be welded.
Table (3) is taken from ASME B31.3, Table 331.1.1. This table indicates when PWHT is
required for some pipes base metals based on pipe thickness. It provides the holding
temperature and time.
2) PWHT required by the service fluid flowing on the pipe.
For carbon and alloy steel pipes, the following service fluids require PWHT
1) All caustic soda (NaOH) solutions, including conditions where caustic carryover may
occur (e.g. downstream of caustic injection points).
2) All monoethanolamine (MEA) solutions (all temperatures).
3) All diglycol amine (DGA) solutions above 138°C design temperature.
4) All rich amino diisopropanol (ADIP) solutions above 90°C design temperature
5) All lean ADIP solutions above 60°C design temperature.
6) Boiler deaerator service
7) Hydrogen service for P-No. 3, 4, and 5A/B/C base materials.
8) All diethanolamine (DEA) solutions.
Table 3: Requirements for PWHT
13
Main Points Regarding PWHT
Maximum heating and cooling rate is 2220C/h divided by the thickness of the weld in
inches.
The minimum area to be included in the heat treatment is three times the pipe
thickness on each side of the welding joint.
At least 300 mm insulation should be applied on each side of the welding joint.
Removal of the insulation should not be done till temperature reach 1500C or below.
Number of thermocouples to be used should be as follow:
a) One thermocouple for pipe diameter 305 mm or less.
b) Two thermocouples for pipe diameter greater than 305 mm up to 610 mm.
c) Four thermocouples for pipe diameter greater than 610 mm.
Sample Report Graph
Figure 4: Sample PWHT Report
14
Flange Bolt Tightening
Pre-Tightening Steps
1) Inspection should be carried to check that gasket, bolts and nuts are of the correct
type based on isometric drawing. It is also important to check that they are free of
damage.
2) Flange faces should be cleaned and free of any damage.
3) The torque wrench to be used must be calibrated or its calibration is still valid prior
to tightening.
4) Check correct use of lubricant.
5) Based on bolt sizes and gasket type, check the table to choose the correct torque
value for tightening. Table (4) gives the recommended torque values.
Table 4: Torque Values for Bolt Tightening
15
Tightening Procedures
1) Flange faces should be properly aligned within acceptable limits
2) Lubricant should be applied to the bolts threads and check that the nut is moving
freely over the bolt.
3) By hand, install the bolts on the flange holes and make sure that it is freely moving
on the hole. Start tightening by hand.
4) Using torque wrench, start bolt tightening following the recommended sequence.
a) For small number of bolts (4-32), the sequence is one bolt against another.
Figure (5) to the left shows an example for the sequence for 24 bolts.
b) For large number of bolts (36-68), start numbering as shown on figure (5) to
the right then the sequence is three or four bolts against another three or
four bolts. Table (5) shows the sequence for 36 bolts.
5) The tightening of bolts should be done in two stages. The first stage with torque
value that is 30 % of the required value and the second stage with 100% of the
torque value.
Table 5: Bolt Tightening Sequence for 36 Bolts flange
Figure 5 : Tightening sequence of 24 bolts and Bolt Numbering for large Number of Bolts (36-68)
16
Pump Alignment
Pump and motor shafts alignment is the process in which both the pump and motor are
adjusted so the two shafts are collinear. The case of 100 % collinear shafts is never the case
in real practice. However, there are acceptable tolerances for shafts misalignment. These
tolerances are based on some standards or vendor recommendation. The alignment process
is very important to rotating equipment because it improves the life of its internal
mechanical components and reduce noise and vibration during operation. In this report, the
described method is Rim and Face method and the given data and photos are for portable
water booster pump with its driving motor.
Misalignment Types
Parallel or Offset Misalignment
Angular Misalignment
The two shafts to be aligned are parallel but
at a distance from each other.
The two shafts to be aligned have an
angle to each other.
Pump and Motor Specifications
The pump and motor to be aligned have the following
specification
Pump RPM is 3540
Motor RPM is 3525
Distance between shafts end (DBSE) is 177.8 mm
Reference Documents
1) SAES -G-005 Centrifugal Pumps 24 February 2008
2) API 686 – Recommended Practices for Machinery Installation and Installation Design
1996
3) Manufacturer’s Data Sheet and Instruction
Figure 8: Manufacturer Pump Information
Figure 6: Offset Misalignment Figure 7: Angular Misalignment
17
Figure 9 : Potable Water Booster Pump General arrangement drawing
Main Equipment Used for Alignment
1) Two dial indicators attached on alignment bracket
2) Micrometer
3) Straight edge
4) Feeler gauge
5) Shims
Figure 10: Alignment Tools
18
Alignment process and procedure
General Requirements
1) Documents related to the alignment process such as drawings, data sheets, DBSE
and recommended tolerances should be available for review before starting the
alignment process.
2) For pump and motor alignment, the pump is the fixed reference of alignment while
the motor is the movable machine to be adjusted. For this reason, the pump and
motor baseplate is designed such that the motor is resting in a position slightly
lower than the pump. By this design of the baseplate, shims can be added or
removed under/from the support foot of the motor.
3) Shims to be used should be of 300 series stainless steel to avoid corrosion.
Maximum number of shims to be used under any foot should not be more than five
shims.
4) Tolerances to be followed for the alignment can be summarized as follow:
a) Misalignment in both radial and axial direction should not exceed 0.05 mm
b) DBSE tolerance should not exceed 0.25 mm
c) For soft foot, movement at each foot should not exceed 0.05 mm
Preliminary Alignment
The preliminary steps of alignment will be performed after the baseplate installed on the
foundation that has been built according to specific level and coordinates. At this stage the
suction and discharge pipes are not connected to pump.
1) Prior to place the pump and motor on their position on the baseplate, machined
surfaces such as foot base and flange surfaces should be checked for straightness
using calibrated level.
2) Adjust the pump on its place and tighten its bolts. Check must be done on the
straightness of the pump shaft because it will be our fixed reference.
3) With the motor placed on its adjustable place on the baseplate, start rough
alignment of the pump and motor shafts as follow:
a) Using the straight micrometer, measure the exact DBSE at 12 o’clock and 6
o’clock positions as seen from motor end. This step will reduce the angular
misalignment in the vertical plane.
b) Using an appropriate straight edge, measure how high is the pump hub from
the motor hub. Add appropriate shims for correction. This step will reduce
offset misalignment in the vertical plane.
c) Repeat step (a) for the horizontal plane. This step will reduce the angular
misalignment in the horizontal plane.
19
d) Using straight edge, measure how the two shafts are horizontally offset from
each other. Move the motor to the left or right for correction. This step will
reduce offset misalignment in the horizontal plane.
4) The alignment bracket with the two dial indicators is installed on the hub of the
pump. Then, we rotate the shaft of the pump to take the reading of the dial
indicators at different position.
a) Zero the two dial indicators at 12
o’clock position and rotate the
shaft to 6 o’clock position and take
the reading of the two dial
indicators. Make any correction if
the misalignment exceeding the
acceptable tolerances.
b) Repeat step (a) for the positioning
of the dial indicators at 3 o’clock
and rotating to 9 o’clock
5) Tighten the motor bolts and check for soft
foot.
Figure 12: Tightening and Soft Foot Check of Motor
Final Alignment
The final alignment steps will be performed after grouting has been done according to the
approved procedure. These steps will be performed as the pipes are connected to the pump
to measure any misalignment during the connection.
1) Before starting the final alignment, check that :
a) All pipes to be connected to the pump nozzles are hydro-tested and dried.
b) All pipe supports are installed according to the isometric drawing.
c) The motor is already solo run and accepted.
2) Install the rim and face dial indicators so that the alignment bracket is fixed on the
motor hub and the two dial indicators are touching the rim and face of the pump
hub.
3) Start aligning the pipe flanges with the pump nozzles as follow :
Figure 11: Alignment Bracket with Two Dial Indicators
21
a) The bolt holes of the flanges should be collinear with the bolt holes on the
pump nozzles. 1.5 mm offset between the hole’s centers is acceptable.
b) Using feeler gauges, adjust the distance between the pipe flanges and pump
nozzle flanges. Maximum distance should not exceed 1.5 mm plus gasket
thickness.
4) Prior to bolt tightening of pipe flanges to pump nozzles, an inspection check should
be carried as follow :
a) Gasket to be used should be inspected for correct type as per the isometric
drawing. A check for gasket damage should be carried as well.
b) Bolts, nuts and washer should be checked for correct type and for any
damage.
c) Pipe and nozzle surface flanges should be clean and dry.
5) After the inspection of step four is completed, start bolt torqueing and tightening.
The torque value and procedure should be as per Armco standard.
6) While we are tightening the bolts, keep tracking the indicators reading for any
change in the alignment. For any misalignment beyond the accepted tolerances,
correction must be carried to bring the misalignment within the acceptable limits.
The correction can be made by shimming or adjusting the pipe supports.
7) Final reading at each 90 degree must be carried and then soft foot check
8) Main contract and YASREF mechanical inspector should check the alignment
tolerances are within acceptable limits or not. Alignment report shall be approved
and signed. Figure (13) show a report for the final alignment process.
9) Coupling shall be installed and tightened.
10) Finally, coupling guard shall be installed.
The next Page show some photos for the final alignment steps
Figure 13: Alignment Report
21
Figure 14 : Final Alignment Steps
Fabric Belt Splicing
Belt splicing is the process in which two belt ends are joined together. At YASREF project,
two types of belt (fabric and steel) are used on a conveyor to transfer coke and pelletized
sulfur from their process units to KFIP. In this report, fabric belt splicing using hot
Vulcanization method will be explained. For proper belt splicing, some factors should be
taken into consideration such as the type of belt, the speed of the belt conveyor system,
transferred material and environment.
22
Specification
The belt to be spliced is EP630/4 which has the following specification
1) The belt reinforcement material is fabric with 4 layers
2) Ultimate tensile strength of the belt is 630 N/mm
3) Thickness of the belt is 14 mm
4) Width of the belt is 1400 mm
Belt speed is 2.03 m/s
The fabric belt is part of the belt conveyor system to be used for transferring
Petroleum Coke from the Delayed Coker Unit to King Fahd Industrial Port.
Design temperature is 750C
Reference Documents
1) DIN 22102-Part 1
2) IS - 1891- Part I
3) Manufacturer recommendations
Main Splicing Equipment
1) Vulcanizing press machine
2) Generator
3) Water tank with pumping
mechanism and pressure
recording
4) Temperature recorder
5) Hook chook
6) Cutting knives
7) Air blowers and grinding
tools
8) Splicing material
9) Cleaning solution
10) Adhesion
Figure 15: Belt Conveyor
Figure 16: Belt Splicing Equipment (1)
23
Procedure
1) First of all, the two belt ends to be spliced and form one continuous belt should be
cut at an angle for better joining. This can be done as shown on the figure (18).
In our case: Belt width (B) = 1400 mm
0.4 B = 560 mm
So, the angle of the cut is:
θ = Arctan (0.4) = 21.800
2) Second, decide on the number of
steps for cutting the belt.
Since the belt is having four layers of fabric, the number of steps is three according
to the rule:
Number of steps = number of layers (plies) - 1
3) Decide on the splice length and step length. This can be found using standard tables.
Table (6) is an example for such tables.
Table 6: Example for Standard Tables of Belt Splicing
According to table (6):
Splice length = 600 mm Step length = 200 mm Number of steps = 3
Figure 17: Belt Splicing Equipment (2)
Figure 18: Cutting Belt Ends
24
4) After decision have been made about the number of steps of cutting, splice length
and step length, the cutting work will start as follow:
a) Start marking the splice length, step lengths and
cover fill in cut.
b) Using the cutting knife, we start with the cover fill
in cut. This cut should be with 25 mm width and at
45 degree angle. Then, remove the rubber cover
from the whole splicing length. After that we cut
the first fabric layer a distance equal to the step
length. Then, continue cutting the second and third
layer.
Figure 20: Cover Fill in Cut and Removing Rubber Cover
c) The same cutting process will be done
for the second belt end but in
opposite direction to the first end.
After cutting is completed, the two
ends will look like as shown on figure
(21).
5) Using the grinding tool, air blower and the
cleaning solution, grind the belt ends and
clean the whole splicing area from any
contamination.
Figure 22: Cleaning and Grinding
Figure 19: Belt Marking
Figure 21: Final Look of Belt Ends after Cutting
25
6) Apply the splicing material on one end of the belt. First of all, a layer of splicing
material should be applied to the whole area to be spliced. An additional 50 mm
splicing material should be added to the upper and bottom cover. Moreover, 25 mm
splicing material to be added to the side edge of the belt.
7) Align the two belt ends. Use clamps to keep the ends aligned with each other.
8) Install the vulcanizing press machine on the two belt ends. The spliced belt is placed
between two hot plates. The belt is protected from being sticking on the hot plates
by two silicon layers. Above the upper hot plate, there is a rubber water tank to be
used for providing the pressing pressure.
Figure 23: Installing Vulcanizing Press Machine on Belt
9) Connect the temperature recorder to the vulcanizing machine and turn on the
generator to provide electricity to the heating plates.
10) Keep heating till the temperature recorder read 70 0C then start pumping the water
to the rubber water tank. Stop pumping the water when the gauge pressure read
150 PSI.
11) Continue heating till temperature reach 145 0C. After that, additional heating time is
required. This heating time is based on belt thickness. The rule is that for each 1 mm
thickness 3 min of heating is required.
In our case:
Belt thickness is 14 mm
Additional heating time = 14 *3 = 42 min
12) When the additional time of
heating is done, the heating is
stopped and machine is left for
cooling. Finally, the vulcanizing
press machine is uninstalled and
the splicing work is done.
Figure 24: Belt Ends after Splicing
26
Case Studies
Case Study (1)
Problem
Molten sulfur is one of the byproducts of the refining process of crude oil. It is produced at
the refinery area at 130 0C. This molten sulfur is needed to be transferred from the refinery
to King Fahd Industrial port (about 4.3 Km) where it will be solidified, stored and then
exported. The problem with molten sulfur is that it solidifies when its temperature drop
below 119 0C. If such case happened during the transferring process, it would cause
damage to pipelines and pumps and stop the production. Describe the process of Molten
sulfur transfer from the refinery to the port and how the problem being solved.
Process
Molten sulfur is produced at different stages of the refining process at temperature 130 0C.
It is then collected and stored in a two big storage tanks in the refinery area. This molten
sulfur is then transferred to sulfur feed drum via molten sulfur pipelines (about 4.3 Km). To
maintain the molten sulfur temperature within 125 to 135 0C, the molten sulfur pipelines is
being electrically heat traced via the skin effect system and insulated.
From the sulfur feed drum, molten sulfur is pumped using sulfur feed pumps to the
pelletizer building. At this stage, molten sulfur temperature is maintained within 125 to 135 0C by electrical heat tracing of the sulfur feed drum and hot oil jacketing of the pipes and
pumps. When the molten sulfur reaches the pelletizer building, it will be solidified in the
form of pellets (2-6 mm pellets). The sulfur pellets is then transported via belt conveyer to
the storage unit. At the storage area, sulfur pellets will be collected. When there is an export
process, the sulfur pellets is pushed using reclaimer to another belt conveyor to shipment
area.
Molten Sulfur Temperature
Maintenance Mechanisms
Hot liquids moving on pipes or stored in
tanks expose to continuous heat
transfer. The heat transfer mechanism
can be by conduction, convection or
radiation. In our case of molten sulfur
pipes and tanks, all three modes
contribute the process of heat transfer.
Heat transfer is directly proportional to
the temperature difference.
Figure 25: Effects of Insulation and Heating on Heat transfer
27
Heat Transfer α Δ T
Δ T = ( TSulfur – TAmbient )
In our case, sulfur is produced at temperature 130 0C and ambient temperature is 15 0C <
Tambient < 45 0C. This implies that the temperature difference is high (85 0C < Δ T <115 0C). In
order to maintain molten sulfur temperature, there should be some mechanism to reduce
the heat transfer and a source for heat to compensate for any heat losses.
Reducing the heat transfer can be achieved by applying an appropriate insulation to the
pipe or tank. Heating sources to compensate heat losses can be achieved by different
methods. In our case of molten sulfur, the heating has been done in three stages with
different methods.
1) Skin Effect Electrical Heat Tracing
System for the 4.3 Km Sulfur Pipelines
In this method, a ferromagnetic heating tube is
welded to the sulfur pipelines that extend for
4.3 Km. Inside the tube, a special insulated type
cable is placed. The cable is connected to an AC
voltage source and end terminated to the inner
surface of the tube. The current flowing in the
tube is only within the internal thickness of the
tube such that no measurable voltage on the
outer surface of the heating tube. The heat will
be generated to sulfur pipeline as follow:
a) 80% of the heating required will be supplied to the pipeline due to I2R losses from
the current flowing on the tube attached to the pipeline
b) 20% of the heating required will be supplied due to I2R losses from the insulated
cable.
2) Electrical Heat Tracing of Sulfur Feed Drum
For the sulfur feed drum, it is being heated using
electrical heat tracing cable. This cable has been
wrapped around the drum and insulated. The cable
supply heat to drum by the I2R losses from the
insulated cable. The cable must be connected to some
controllers and regulators. These controllers and
regulators will maintain the molten sulfur within the
required temperature (125 -135) 0C. They are also help
in protecting the cable from being over heated which
can damage the cable and the sulfur inside the tank.
Figure 26: Skin Effect Electrical Heat Tracing
Figure 27: Electrical Heat Tracing of Sulfur Feed Drum
28
3) Hot Oil Jacketing of Pipes Extending from Feed Drum to Pelletizer
Hot oil jacketed pipes have a special design to maintain molten sulfur as liquid with
temperature 131 0C. In fact, hot oil jacketed pipes consist of two coaxial pipes. The inner
pipe is for the process fluid which is here the molten sulfur. The outer pipe is for the heated
oil which will be circulated on the pipes. The hot oil which will be supplied to the pipes has a
special system. This system consists of:
Hot Oil Heaters
Hot Oil Storage Tanks
Hot Oil Circulation Pumps
Oil Loading Pumps
Expansion Tank
Figure 28: Hot Oil Jacketed Pipes
Figure 29: Hot Oil System
29
Case Study (2)
Problem
While performing pump alignment, technicians could not approach good pump alignment
within accepted tolerances.
Problem Effects
For any construction activity, the contractor sends a request for inspection (RFI) to YASREF
quality engineer who is responsible for monitoring that type of activity. For this activity, the
RFI was raised with a specified time for inspection. When the inspector went to site to
inspect the alignment and close this work, the contract company was facing the problem
that the pump is not responding to alignment. The inspector will not wait till the problem is
solved so he rejected the RFI. This means that the contractor side should issue another RFI
when they resolve the problem. Such problem cause a time delay in the project progress
and time is money for both the contract company and the owner company.
Problem Investigation and Solution
A first suggestion was to recheck that the dial indicators and alignment bracket are in good
condition and not giving wrong readings. However, this was not the cause of the problem.
Then, the rotating equipment engineer suggested the use of a temporary pipe support at
different location and performs the alignment process. At one position of the temporary
pipe support, the alignment gives good results. Referring back to the isometric drawing,
engineers found that a permanent pipe support is not positioned on its designed location.
Due to this mistake, more stresses developed on the flange which causes the alignment not
to respond.
Figure 30: Temporary Support on Pipe
31
Case Study (3)
Problem
During solo run test of Motor -114-GM-0007B, the motor show high vibration that is beyond
the site accepted criteria.
Figure 31: Motor Solo Run
Investigation of the Root cause of the vibration
First of all, the vibration of the motor was identified as caused due to a problem in
the bearing of the motor (Roller Bearing). As an action to solve the problem, motor
bearings were replaced. However, the vibration still exists when motor reinstalled
and tested at site.
When bearing replacement did not give positive results, YASREF requested General
Electric Company which manufactured the motor to perform more inspection to
identify the root of the vibration. The company performed the test into five steps.
1. Solo run in standard conditions
2. Solo run with the fan cover of the motor is loosened
3. Solo run while bolts of the motor are not tightened to the baseplate
4. Solo run with sof shoe shim
5. Impact test to find the natural frequency of the motor.
31
Table 7 : Vibration Readings of Motor Solo Run at Different Condition
1. Solo run in standard conditions
Motor Tag. 114-GM-0007B
Site Readings (mm/s RMS)
Site Criteria (mm/s RMS)
Motor DE H 4.63 2.8
Motor DE V 1.2 2.8
Motor DE A 0.63 2.8
Motor NDE H 6.32 2.8
Motor NDE V 0.96 2.8
2. Solo run with the fan cover of the motor is loosened
Motor Tag. 114-GM-0007B
Site Readings (mm/s RMS)
Site Criteria (mm/s RMS)
Motor DE H 2.73 2.8
Motor DE V 1.1 2.8
Motor DE A 0.45 2.8
Motor NDE H 4.12 2.8
Motor NDE V 1.01 2.8
3. Solo run while bolts of the motor are not tightened to the baseplate
Motor Tag. 114-GM-0007B
Site Readings (mm/s RMS)
Site Criteria (mm/s RMS)
Motor DE H 0.92 2.8
Motor DE V 0.56 2.8
Motor DE A 0.46 2.8
Motor NDE H 1.08 2.8
Motor NDE V 0.96 2.8
4. Solo run with sof shoe shim
Motor Tag. 114-GM-0007B
Site Readings (mm/s RMS)
Site Criteria (mm/s RMS)
Motor DE H 1.47 2.8
Motor DE V 0.55 2.8
Motor DE A 0.27 2.8
Motor NDE H 1.72 2.8
Motor NDE V 0.57 2.8
The impact test in standard condition resulted in 129 Hz horizontal natural frequency.
The impact test with sof shoe shim resulted in 99 Hz horizontal natural frequency.
32
Conclusion
The natural frequency at standard conditions is 129 Hz which is 7.5 % of the forcing
frequency 120 Hz as seen from spectra figure (34). While in recommended practice, natural
frequency should be 15 -20 % away of the forcing frequency. This forcing frequency excites
the natural frequency resulting in high vibration records.
In the case of sof shoe shims installation, the natural frequency recorded dropped from 129
Hz to 99 Hz. This natural frequency is 17.5% away from the forcing frequency. The drop in
natural frequency resulted in drop in the vibrations. The sof shims installed under motor
feet act as damping elements.
General electric suggested the use of the sof shoe shims as permanent solution. However,
this solution was rejected by YASREF. Now, general electric is going to perform vibration
analysis at their shop for new motors. If the new motors give good vibration results at shop
and not accepted results at site, investigation should be carried to site parts such as
foundation, grouting and land.
Figure 32: Vibration spectra
33
Conclusion and Recommendation
The coop training program was a great opportunity in which I spent 28 weeks working in a
real engineering environment. During that period, I have been able to relate the theoretical
part studied at KFUPM University with the practical part seen in real engineering
application. For example, I have been introduced to many mechanical equipment such as
pumps, compressors, pipes, gate valves, motors and many others that I have never seen in
my academic study. It was also time for me to learn how construction activities being
conducted and organized via governing standards such as ASME and SAES. Moreover, I got
some overall idea about the scope of some units of the refinery.
In addition to the technical and engineering knowledge gained, I have been able to improve
my own skills such as communication and team work skills. There have been many
engineers and technicians from different countries that I have worked with them. Improper
communication or team work may adversely affect the progress of the project. During the
training period, I have also learned how to be patient since it was required from us to work
eight hours a day at field offices. During working hours, you have to go for inspection many
times a day. I have also learned how meetings between main contract companies and
YESREF are conducted and how they discuss the project progress and problems faced.
34
References
1. YASREF Overview. (n.d.). Retrieved from http://www.yasref.com/about/overview
2. Project Overview. (n.d.). Retrieved from http://www.yasref.com/project/overview
3. Splicing and repair manual. Retrieved from http:// www.blairrubber.com /pdf/Blair_
Splicing Manual.pdf
4. Mullan, H. Heat tracing basics. [PowerPoint slides]. Retrieved from http:// www.
Mullanconsultants.com/pdf/heat_tracing/Heat%20Tracing%20Basics_SLIDES-HRM-
300410.ppt
5. PENTAIR. (n.d.). Skin-effect heat-tracing system (STS) [Brochure]. Retrieved from
http://www.pentairthermal.com/Images/GB-RaychemSTSskineffectTracing System
APAC-SB-H57124_tcm432-37908.pdf
6. TEMPCO. (n.d.). Heat trace cable [Brochure]. Retrieved from http://www.tempco.
com/Tempco/Section6.pdf
7. Towsley, G. (n.d.). Alignment. Retrieved from http://www.grundfos. com/ content /
dam/CBS/global/whitepapers/Whitepaper%20-%20Alignment.pdf
8. The four easy steps to good shaft alignment. Retrieved from
http://www.carlylecompressor.com/Files/Carlyle_Compressor/Local/US-en/
documents/039-185_5FHShaftAlignment_lowres.pdf
9. YASREF. (2013, October 22). Sulfur pelletizer and loading operation and maintenance
manual. Yanbu, Saudi Arabia: Author.
10. Power Piping,ASME Code for Pressure Piping, B31. (2007). New York: The American
Society of Mechanical Engineers.
