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VIETNAM ELECTRlCITY / TEPSCO o MON THERMAL POWER PLANT
VOLUME 6 FLUE GAS DESULPHURIZATION SYSTEM
Clause No.:
CONTENTS
g
6. 1 GENERAL
..........................................................................................................
6-1-1
6.1.1 Introduction
.........................................................................................
6-1-1
6.1.2 Design Requirements
...........................................................................
6-1-3
6.1.2.1 Basis of Design
.................................................. 6-1-3
6.1 .2.2 Process Conditions ... 6-1-4 6.1.2.3 By-product
Conditions ................................................
.6-1-5
6.1.2 .4 Performance Guarantee
......................................................... 6-1-5
6.1.3 Drawings to be Submitted
....................................................... ~~~~ .. ~"
.6-1-7
6.2 MECHANICAL WORKS
.................................................................................
6-2-1
6.2.1 General .. .. ............... .. . .. - .," .. .. . .. ..
. ....," . 6-2-1 1
6.2.2 Detail Specification
..............................................................................
6-2-3
6.2.2.1 6.2.2.2 6.2 .2 .3 6.2 .2 .4
6.2.2.5 6.2.2.6 6.2.2.7
6.2.2.8
6.2 .2.9
Limestone Storage System ....................................
.6-2-3 Absorbent Milling/Preparation System
................................. 6-2-5 Flue Gas Flow System
..........................................................
6-2-7
Absorbing System.. . .. . .,.. ...... ... ..... . ......6-2-8
Gypsum Dewatermg System............ .... . ......... ..6-2-10 0
Gypsum Storage, Handling and Transportation System .. 6-2-14 4
FGD Make-up Water Supply System.. . ... ...............6-2-15 5
Building and Structure.. . .,.... ........... .... 6-2-16 Void
6.2.2.10 Materials.. ... . .... .... .,....... ... ... .. 6-2-1
7 6.2.2.11 Process Outline ................ .... ..... . .... ....
.... . . .... ...6-2-17 6.2.2.12 The Margins for the Design
Capacity
and Pressure of Equipment .. . ...... .. ....... . ... ... ..
..6-2-17 7
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VIETNAM ELECTRICITY / TEPSCO
6.2.3
6.2 .4
6.3 TEST AND INSPECTION
................................................................................
6-3-1
1 6.3.1 General ........... .. ... .. .... . .......... ...
...-. ........ .. .. 6-3-1
1 6.3.2 Records and Certificate . ... ......... .. . .. ...
..... .. . . ..6-3-1
2 6.3.3 Workshop Tests.... ... .. ....... .. ... . ...... ......
.. ... ... 6-3- 6.3.3.1 6.3.3.2
General .. . . ......... ..... . ...... . . ........ ... ...
..... 6-3-2 Mechanica1 Works .. . . . . . ....... . . . ..
.....6-3-3 3 6.3 .3 .2.1 Tests on Materials . . . . . . ..
......... 6-3-3 3
6.3.3 .2.2 Ultrasonic Examination .. .. . . .. ........6-3-4 4
6.3 .3 .2 .3 RadiographicExuinatlOn.. ...... . . .. ...6-3-4 4
6.3.3 .2.4 Hydrostatic Test .. . ..... . ... ..-....., .....
..........6-3-5 6.3.3 .2.5 Pipework .. .... . ..... ..... . .,
6-3-5 5
6.3.3.2 .6 Pumps....,. . ...... ., .. .... ......,.
............... 6-3-6 6.3.3.2 .7 Fans .. .., .. ... . . ..,... ....
. . . ...6-3-7 6.3 .3.2.8 Steel Structure .. ......., ".,....... ..
...6-3-7 6.3 .3.2.9 Liftin1g Equipment and Cranes .. .... ....6-3-7
6.3.3.2 .10 Insulation Material .. ....... .. ..,....-....... .. .
6-3-7 6 .3 .3 .2 .11 Lining .. . . ...,........... -. .,. 6-3-7
6.3.4 Test and Inspection at Site
..................................................................
6-3-9
6.3.4.1 General
.................................................................................
6-3-9 6.3 .4 .1.1 Inspection and Test Equipment
.......................... 6-3-9 6.3 .4.1.2 General Inspection
Procedure .......................... 6-3-10 6.3 .4.1.3 Painting
Inspection Procedure ......................... 6-3-11
6.3.4.2 Mechanical Works
...............................................................
6-3-12 6.3 .4 .2.1 Welding and Welding Documnts
.................... 6-3-12 6.3 .4 .2.2 Site Wlding Control
........................................ 6-3-16 6.3 .4 .2.3
Absorber and Other Equipment ....................... 6-3-20
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VIETNA1l1 ELECTRICITY / TEPSCO
6.3 .4.2 .4 6.3 .4.2.5 6.3 .4.2.6 6.3 .4 .2.7 6.3 .4.2.8
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Unfired Pressure Vessels and Pipeworks ......... 6-3-20 Tank and
Silo ................................................. 6-3-21
Rotating Equipment ......................................... 6-3-21
Lifting Equi pment ............................................ 6-3
-21 Functional Tests
............................................... 6-3-22
6.3 .4.2.9 Safety Valve Setting
......................................... 6-3-22 6.3 .4.2.10 Plant
Load Tests ...............................................
6-3-22
6.3.5 Performance Test. .. . ...... ..... .. . .. ... . . ..
..... 6-3-24
6.3.5.1 General
...............................................................................
6-3-24
6.3 .5 .2 Desulphurized Flue Gas... . ..., .... . .
................6-3-24 6.3 .5.3 By-product Gypsum .. . ..........
., . ........ . . 6-3---2 5 6.3.5 .4 0ther Items 0fPerformance
Guarantee .. ..... .............6-3-2 5
6.3.6 Auxiliary Power Consumption .. . . .. ........ "...
............. ...6-3-26
6.3.6.1 Auxiliary Power Consumption
........................................... 6 3-26
6.3.7 Final Acceptance . ... .. .. .. .. .. .. .. .. .. .. .. ..
.. .. .. . .. .. .. .. .. ........ .. . .. .. .,.. .. .. .. .. ..
.. .. .. .. .. ................ .. .. ......6-3-27
6.3.7.1 General. ... .. .. . .. .. ... .. .. .. . . ...........
.. .. .. .. .. .. .. .. .. .. .. .. .. .. . .. ......,
..................6-3-27 7 6.3 .7.2 Plant Inspection Prior to Final
Acceptance .. ... .. .. .. .. .. .. .. .. .. .. .. .. 6-3-2
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
VOLUME 6 FLUE GAS DESULPHURIZATION SYSTEM
6.1 GENERAL
6.1.1 Introduction
(a) This Volume cm%supply, construction, installation, testing,
commissioning and inspection of Flue Gas Desulphurization System
(hereafter FGD System).
(b) The quantities of equipment as mentioned in this Volume
shall mean those for one (1) unit, un1ess otherwise specified.
( c) ldentical design d interchangeability shall be taken into
consideration for all equipment to the maximum extend.
(d) The commercial and general technical requirements shall be
covered by the Specification ofVolumes 1 and 2. The general
rangement and system diagram shall be generally as indicated in the
relevant Bid Drawings.
(e) The FGD system sha11 be of wet type limestone-gypsum with
forced oxidation method having a capacity of 300-330 MW/one (1)
absorber module. The conceptual configuration ofthe FGD system for
Unit Nos. 1 and 2 is as shown in the Drawing No. OM2FD-I001 in
Volume 11 , but not be limited to. (i) One (1) flue gas flow system
and one (1) absorbing system shall be supplied to Unit
No. 2 exclusively. (ii) The existing stand-by equipment
currently common to Unit Nos. 1 and 2 shall be
employed for Unit No. 2 as normal operating equipment.
Therefore, some equipment shall be designed and installed without
stand-by equipment. Other equipment, if necessary, shall be
provided to ensure the completeness of the function as FGD system
for Unit No.2.
(iii) FGD systems for Unit Nos. 1 and 2 shall be isolated from
each other in case of two (2) units in operation
simuItaneously.
(t) The FGD system shall be provided with the following, but not
b limited to, components and complete accessories. (i) Wet type
limestone-gypsum flu gas desulphurization systm complete with
all
necessary auxiliary equipment (ii) Limestone storage system
(iii) Absorbent milling and preparation system
6-1-1
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VIETNAM ELECTRICITY / TEPSCO
(iv) Flue gas f10w system (v) Absorbing system (vi) Gypsum
dewatering system (vii) Void (viii) Void (ix) FGD make up water
supply system
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(x) Piping, valves and thermal insulation for all
systems/equipment (xi) All instrumentation and controls necessary
for the safe, efficient and reliable
operation ofthe equipment included in this Specification - refer
Volume 7. (xii) Structural steel required to support the FGD and
other equipment within the
scope of this contract (xiii) Electric motors for plant - refer
Volume 2 (xiv) Power, control and instrument cable and cabling -
refer Volume 2 (xv) Cable trays, conduits and marshalling cubicles
- refer Volume 2 (xvi) Grounding system - refer Volume 2 (xvii)
Lighting system for all plant within the contract - refer Volume 2
(xviii) Permanent enclosures to give protection for plants and
personnel against the
weather in the areas, where considered necessary (xix) All
tapping points and associated valves (xx) Control valves, dampers
and alllinkages, actuators and associated mountings (xxi) All local
panels of the instrumentation and control shall be cooled with
air-conditioner for the safe operation of system (xxii) Spare
pas and special tools
Note: The Contractor shall provide any and all equipment,
materials and accessories as required for a complete set ofthe FGD
system and include for installation and trial operation ofthe
equipment in addition to the items specified in the above.
Furthermore, the existing equipment currently common to Unit Nos. 1
and 2 are intenddto serve for Unit Nos. 1 and 2 individually anor
in common, and all necessary provisions and equipment required for
ensuring the completness of function as FGD system for Ut No. 2
shall be providd by the Contractor. Although not clearly specified
in the above, any embedded materials for foundation, base plates,
grouting materials, suppos electric motors, accessory piping,
valves, instruments and blower silencers for the FGD system as weII
as the piping rack foundation related to th FGD system shall be
included in the scope ofwork.
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VIETNAM ELECTRJCITY / TEPSCO o MON TflERMAL POWER PLANT
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6. l.2.1 Basis of Design } 3
(a) The FGD System shall be designed to reduce sulf dioxide
emissions total suspended particulate emission in accordance with
Vietnamese Standard in Clause 2. l.3.5. Equipment shall be sizd
based on the fuel oil firing.
6. 1.2 Design Requirements
(b) The FGD system shall have a capacity to operate with full
gas flow at BMCR satisfying the rquired S02 concentration at stack
inlet. The flue gas conditions at BMCR * per FGD system shown below
shall be specified by the Bidder.
* :BMCR: Boiler Maximum Continuous Rating
Flue Gas Flow Rate
t
V R K N
m
m
m %
JM
Flue Gas Temperature FGD inlet Sulfur Dioxide (S02)
e U J X
F 0
(c) The guaranteed performance at 100 % Rated Output is shown
below.
: N ot less than 90 % : Not more than 500 mg!m3
(at 100kPa, 298K, dry) (d) The FGD system shal1 be capable of
operating under the conditions stated in Clause 2.1 .4.
S02 removal efficiency at stack inlet S02 concentration at stack
inlet
(e) The FGD system shall be operated whn the fuel oil is fired
in the boiler.
(f) The FGD system shall be capable of operating continuously at
loads equal to and above 20 % of rated out put when firing fuel
oil.
(g) The FGD system shall be of proven design. Designs
incorporating componnts which may be considred of prototype in
nature will not be accepted.
(h) The equipment and components shall b designed and suppoed to
permit free expansion and contraction without causing xcssive
strains, distortion or leakag.
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
(i) Parts subject to wear, erosion, corrosion or other
deterioration, or requiring adjustment, inspection or repair shall
be accessible and capable of reasonably convenient removal,
replacement and repair. All such parts shall be of suitable matria
1.
G) The equipment shall be designed to permit interchangeability
of parts and ease of access during inspection, maintenance and
repair.
6.1 .2.2 Process Conditions
(a) The FGD plant shall be designed based on the data tabled
hereinafter.
(i) Desulphurized flue gas condition Desulphurized flue gas
shall meet the followings:
Parameter Limit Conditions
Desulphurization efficiency N ot less than 90 % at stack
inlet
S02 concentration Not more than 500 mg/m3 (at 100kPa, at stack
inlet 298K, dry) Water droplet content Not more than 150 mg/m3 N,
at mist eliminator outlet dry
Flue gas temperature Not less than 91 oC at stack inlet
Flue gas temperature Not less than 90 oC at stack outlet
(ii)Limestone Crushd limestone specified hereinafter will be
supplied for the Absorber modules as limestone slurry.
Parameter Unit Value CaC03 content wt% 95 - 98 Analysis:
MgO wt% 0.97 Si02 wt% 0.37
Ah03 wt% 0.28 --_.--"_--
Bond work index k Wh/ton of limestone 10 (estimated) Solid
limestone (density) kg/mJ 2400-2600 Solid limestone size mm less
than 20
(max.50) The Bidder shall provide quantitatively the technical
information along with all
6-1-4
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
The Bidder shall provide quantitatively the technical
information aloiiwith all supporting explanation and data in case
the CaC03 content is 10.'v? above one with regard to the following,
but not be limited to: Evaluation ofthe impact on the performances,
such as limestone ption
gypsum specification, power consumption, etc. Evaluation of the
impact on the specification of the equipment fof1he Original
Bid Proposal A, such as absorber, recycle pump, limestone ball
mill, vacuum filter, etc.
Evaluation of the impact on the specification of the equipment
for the existing eqmpment
(iii) Make-up Water The clarified water for FGD system shall be
supplied by the Water Treatment Plant. The chlorine (CI)
concentration of make-up water is 50 mg/l for design of FGD system.
The specification ofthe clarified water is shown in Volume 2 of
14.
(iv) Chlorine Concentration FGD system shall be designed so that
the chlorine concentration in FGD system may not exceed 2,000 mg/l
under any circumstances. The material exposed to the slurry shall
be selected so that it may withstand 10,000 mg/l of the chlorine
concentration in the slurry.
6.1.2.3 By-product Conditions
(a) Gypsum Parameter Value, Description
Purity (CaS04. 2H2 0) Not less than 95 % (dry basis) Particle
size (Mean Particle Siz) Not less than 50 micron meter Moisture
content Not more than 10 % pH value 5 to 8
(b) Waste water Under normal operation, the evaporated water in
hot f1ue gas and moisture in gypsum will be considered to be almost
balanced in water consumption in FGD and the amount of waste water
to be bled off will be expected to be very small. The waste watr
from FGD system shall, therefore, be treated by the waste water
treatmnt facility. The accptable waste water specification is shown
below:
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
Item Unit Temperature Oc < 56 pH - 5 to 8 Suspended Solid
mg/l 41 ,000 Ca2+ mg/l < 500 Na+ + K+ mg/l < 2,700
Mg+ mg/l < 7,000 NH4+ mg/l < 17,100 cr mg/l 2,000 N03-
mg/l 250 SO/- mg/l < 90,000 COD (Mn) mg/l < 2,700 Quantity
m3/d 16
6. 1.2.4 Performance Guarantee
(a) The following items shall be guaranteed when the flue gas as
stipulated in Clause 6.1.2.1 Basis of Design is led to the FGD
System.
Limestone/removed sulfur dioxide ratio Limestone consumption
Desulphurization efficiency (at stack inlet) Maximum S02
concentration-(at stack inlet) Water droplet content (at mist
eliminator outlet) Flue gas temperature (at stack inlet and outlet:
It shall be proved by the
theoretical calculation with the temperature at stack inlet that
the temperature at stack outlet is not less than 90 oC.)
Byproduct gypsum conditions: purity, particle size, moisture
contntandpH value
Make-up water consumption
(b) The correction curve of the guaranteed performance for each
related parameter shall be submitted for approval. In case that the
actual operating conditions deviate from the design conditions, the
correction methods of the guaranteed performancs shall be confirmed
and approved by EVN in advance of operation.
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
6.1.3 Drawings to be Submitted
The following shall be submitted as a minimum, but not be
limited to:
(1) Basic Engineering Drawing List with Issue Date Basic Design
Requirement . FGD System Description Process Flow Diagram and
Utility Flow Diagram Material Balance Sheet or Stream Data
Equipment List Capacity Calculation Sheet or Particular Study for
Equipment . General Arrangement Correction Curve for Guarantee
Value Anticipated Performance Curve along Full Range ofLoad Piping
and Instrument Diagram (Process and Utilities) Set Point List
The Contractor shall submit Correction Curves for Guaranteed
Performance and Anticipated Performance Curves on each different
parneter* basis covering the range between BMCR and 20% RO for EVNs
approval before the kick-offmeeting. The Contractor s negligence to
the above may result in rejection of approval of all related
drawings. *: The parameters shall be as follows, but not be limited
to .
Flue gas conditions: FGD inlet S02 concentration including
maximum S02 concentration to be anticipated in operation FGD inlet
flue gas flow rate between BMCR and 20% RO FGD inlet particulate
matter concentration and composition
Limestone: Purity of limestone Limestone composition
. Operating conditions: Liquid/gas ratio or no. of operating
recycle pumps pH value of absorber recycle slurry
(2) Absorber . Engineering Drawing . Assembly Drawing
ofIntemals, Spray nozzle, Spray pipe network, Mist Eliminator
(ME), ME wash nozzle, ME wash pipe net work, Air sparger, Air
sparger network including Dimension and Material of
Construction
6-1-7
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VIETNAM ELECTRICITY / TEPSCO OMONTHER1ALPOWER PLANT
Detail of Casing, Support and Structure Calculation Sheet of
Absorber F oundation and Loading Data Specification of Resin Lining
Lining Work Procedure
(3) Mechanical Equipment (Absorber Recycle Pump, Booster Fan,
GGH, Oxidation Air Blower and Others) Data Sheet Performance Curve
General Arrangement Drawing Cross Section Drawing anor Assembly
Drawing of Mor Component (with material of construction)
Lube Oil & Utility Flow Diagram, if any Lube Oil &
Utility Piping & Instrument Diagram, if any Foundation and
Loading Data Utility List Sound Insulation Calculation Sheet, if
required
(4) T:lk Sump Engineering Drawing Foundation and Loading Data
Specification of Lining, if any Lining Work Procedure, if any
(5) Piping General piping rangement drawing, lists and
calculations specifed in Clause 2.2.2.1.8 for the piping system in
turbine island.
(6) Flue Outline Drawing of Flue and Support including Dimension
and Material Calculation Sheet of Flue and Support Foundation and
Loading Data of Support
(7) Construction . Installation Procedure for Absorber, GGH, BUF
and Oxidation Air Blower Oil Flushing Procedure Commissioning
Procedure . Mechanical Run Procedure
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VIETNAM ELECTRICITY / TEPSCO
(8) Quality Assurance FGD Quality Management Manual Inspection
and Test Plan Shop Test Procedure Shop Test Report Site Test
Procedure Site Test Report Witness Test Procedure Witness Test
Report
(5) Operation & Maintenance Operation Manual
( Maintenance Manual Overhaul Plan for Major Equipment Spare
Part List (Essentia1 and Recommendable) Lube Oil List
(6) Performance/Acceptance Test
o MON THERJI1AL POWER PLANT
Performance Test Procedure inc1uding Chemical Analysis Manua1
Performance Test Report
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VIETNAM ELECTRICITY ITEPSCO o MON THERMAL POWER PLANT
6.2 MECHANICAL WORKS
6.2.1 General
(a) All material, designs, procedures, calculations,
manufacture, construction, inspection and testing shall conform to:
(i) The Vietnamese regulations as specified in Clause 2.2.1.1 and,
(ii) The criteria and recommendations of the relevant Standards and
Codes of practice as specified in Clause 2.2.1.1.
(b) The FGD system complete with all auxiliaries, shall be
designed, constructed and tested to conform to approved standards
and shall meet the requirements of(a) (b).
(c) The FGD system shall include, but not be limited to, the
following: The conceptual configuration of FGD system for Unit Nos.
1 and 2 is shown in Drawing No. OM2FD-I002 Flue Gas
Desulphurization System, Process Flow Diagram in Volume 11. (i) One
(1) existing limestone handling train, capable of unloading three
hundred
(300) tons of limestone/four (4) hours and supplying the
required limestone from the limestone ship unloader to the
limestone silo The existing limestone conveyor to the limestone
silo (Limestone Conveyor 01-BC-04) shall be modified to transfer
the limstone to No. 1 Limestone Silo and No. 2 Limestone Silo.
(ii) One (1) limestone silo, for one (1) FGD system. The silo
shall have a net storage capacity equivalent to limestone demand
required for seven (7) days operation of n FGD system on the design
condition
(iii) One (1) 100 % limestone slurry milling train which is one
(1) of the existing two (2) trains and meets the requirements for
one (1) FGD absorber system shall be employed for Unit No. 2. One
(1) limestone weigh feeder, Unit 2 reagnt feed tank, pump and
auxiliaries shall be provided.
(iv) One (1) 100 % capacity absorber module including oxidation
system shall be provided. One (1) existing oxidation air blower
shall be employed for Unit No. 2.
(v) One (1) 100 % vacuum filter train which is one (1) ofthe two
(2) trains shall be employed for Unit No. 2. The vacuum filter
shall dewater the spent slurry produced by one (1) absorber
module.
(vi) Flue from the break point to the connection point including
inletloutlet dampers and by-pass damper
(vii) Flue gas reheating system to prevent the corrosion of
stack material and white smoke
(viii) Void
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VIETNAM ELECTRICITY / TEPSCO OMON RMAL P.'RPLANT
(ix) FGD make-up water system (x) Pumps and motors (including a
stand-by for each kind ofpump) (xi) Tanks and agitators, and sumps
(xii) Utility piping, instrument piping and piping support
; (xiii) AIl necessa alarms, control and instrumentation system
(refer to Volume 7) (xiv) AIl high and low voltage electrical
equipment, cable and wiring (refer to
Volum 8) (xv) Laboratory equipment and instruments (xvi) Void
(xvii) Void (xviii) Void (xix) Civil work and site construction
(xx) Factory test and inspection (xxi) Commissioning and adjustment
at site (xxii) Performance test
(d) The terminal points not shown in Volume 11 of 14 shall be
provided by the Contractor.
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
6.2.2 Detail Specification
6.2.2.1 Limestone Storage Svstem
(a) The crushed limestone of which grain size is 20 mm in
average (max. 50mm) is conveyed to the limestone silo by the
existing limestone bucket elevators and conveyors. The existing
belt conveyor (limestone belt conveyor 01-BC-04) transfers the
limestone to No. 1 limestone silo. This limestone conveyor -BC-04
shall be modified or replaced with new one of the same capacity
completely, in order to supply limestone to both NO.1 Limestone
Silo (existing) and NO.2 Limestone Silo (to be supplied by Unit 2
Contract). The Conveyor shall be reversible. The construction time
shall be completed within a week, not to affect th limestone supply
to Unit 1. In case of modification of the existing conveyo the
warranty period for it shall be two (2) years even though it
contains the equipment and parts supplied in Unit 1 Contract.
(b) The existing system upstream of the bucket elevator is so
designed that the block of limestone is unloaded by the limestone
unloader from barges (300ton/ship) at the jetty and transported to
a limestone silo by the conveyors and the bucket elevators through
a limestone crusher for four (4) hours .
(c) Void
(d) The conveyors have been designed, manufactured and
constructed to prevent ingress of rain and emission of fine
limestone particles.
(e) The existing equipment to remove effectively detonators and
scrap iron is installed on the conveyor system between the
limestone receiving hopper and limestone crusher.
( The block of the limestone is crushed by the existing
limestone crusher installed between the limestone unloader and the
limestone silo.
(g) The existing limestone crusher is designed, manufactured and
constructed to prevent vibration, noise and emission of fine
lmestone particles under all operating conditions.
(h) The amount of the limstone is measured with the limestone
weighing measure.
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
(j) One (l) silo (No.2 Limestone Silo) to be installd nearby the
existing limestone silo and one (1) limestone weigh feeder shall be
supplied. The limestone shall be fed by the modified limestone
conveyor (01-BC-04) and shall be discharged to one (1) limestone
ball mill (No. 2 limestone ball mill) through the limestone weigh
feeder. The limestone silo shall be provided with one (l) spare
nozzle for the future weigh feeder.
(k) le net capacity of the NO.2 Limestone Silo is equivalent to
the limestone demand for seven (7) days operation of an FGD system
on the design conditions but is not less than 1,000 t.
(1) All necessary provisions shall be made by the Contractor in
order to employ the eXlstmg eqmpment.
(m) Specification ofthe existing equipment The specifications of
the existing conveyor system and the limestone silo, for the Bidder
s reference, are as follows:
. Equipment Name: Limestone bucket elevator for limestone silo
Quantity: 1 Capacity: 90 h
. Equipment Name: Limestone belt conveyor 01-BC-04 Quantity: 1
Capacity: 90 t/h
. Equipment Name: NO.l Limestone Silo Quantity: 1 Capacity:
1,000 t
As for th terminal points ofthe above, refer to Volume 11 of
14.
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
6.2.2.2 Absorbent MillinglPreoaration Svstem
(a) The absorbent millinglpreparation system consists of two (2)
limestone weigh feders a ball mill train, a reagent feed tank and
associated pumps and a agitator. The ball mill train consists of a
ball mill, a mill product tank, a mill product pump, a classifier,
a distributor and auxiliaries.
(b) Two (2) existing ball mill trains shall be used for Unit
Nos. 1 and 2 commonly, but isolated from each other while two (2)
units in operation simultaneously. The limestone shall be led to a
weigh feeder from NO.2 limestone silo and to No. 2 limestone ball
mill. NO.2 limestone ball mill is fed with the limestone from
either of NO.l limestone silo or NO.2 limestone silo and the
reclaim water from either of Unit Nos.l or 2. The limestone solids
shall be ground to suitable particle size in the milling system and
finally fed to Unit Nos. 1 and 2 reagent feed tanks
accordingly.
(c) The system shall be capable of supplying the limestone
slurry to one (1) FGD absorber system through its own reagent feed
tank.
(d) The reagent feed tank shalI be installed downstream of the
mi lI ing systems, to store the limestone slurry before it is fed
to the absorber module. The tank shalI be sized for five (5) hours
operation storage on the design conditions. Reagent slurry shalI be
fed to the absorber module by the regent slurry feed system.
(e) The reagent slurry feed system of 100 % capacity shall be
provided for reagent feed tank.
(f) The sump common to Unit Nos. 1 and 2 has been instalIed. The
drainage from the systems shalI be collected in the sump and
retumed to the system adequately by the existing sump pumps.
(g) All necessary provisions shall be made by the Contractor in
order to employ the eXlstmg equipment.
(h) Specifications ofthe existing equipment The specifications
of the existing ball mill system, for the Bidder s refernce are as
follows:
. Equipment Name: Quantity: Capacity:
No. 1 / No. 2 Ball Mill 2 7 t1
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VIETNAM ELECTRICITY / TEPSCO
Motor rating:
. Equipment Name: Quantity: Capacity: Dimension: Accessory:
Equipment Name: Quantity: Capacity: Head: Motor rating:
Equipment Name: Quantity: Capacity: Dimension: Accessory:
N
m W :
m
m M
E @ H M
No. 1 / No. 2 Mill Product Tank 2 12 m3
2,438 ID x 2,753 H Agitator
No. 1/ No. 2 Mill Product Pump 2
46.8 m3fh 5 mAq 37kW
Reagent Preparation Area Sump
25 m3
3,050 x 3,050 x 3,650 H Agitator
Reagent Preparation Area Sump Pump 2 60 m3fh 18 .3 mAq 15 kW
As for the terminal points of the above, refer to Volume 11 of
14.
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
6.2.2.3 Flue Gas Flow Svstem
(a) The dirty flue gas leaving the ESP (electrostatic
precipitator) will flow into the absorber module through the GGH
(gas-gas-heater). The dirty flue gas shall be distributed in the
absorber module as even as possible.
(b) The c1ean gas leaving the absorber module shall flow through
the GGH into the stack which is shown in the Drawing Nos. OM2CV-12
to 1208 in Volume 11.
(c) The bypass flue shall be provided between the FGD inlet flue
and the FGD outlet flue. In the event of emergency, this 100 %
bypass flue shall enable the entire flue gas to flow to the stack
directly without being introduced to the FGD system.
(d) There are three shut-off pe dampers associated with the FGD
system. These dampers shall be located at FGD inlet, FGD outlet and
the bypass flue. During normal operation, the bypass damper is
closed in order to direct the entire flue gas to the absorber
module for treatment. In case where the FGD has to be bypassed for
operationaI reasons, the absorber shall be isolated cIosing dampers
at the inlet and outlet ofFGD.
(e) GGH system shall be provided for prevention of stack tube
material from corrosion and ofwhite smoke dispersion.
(f) The sound pressure level measured at a position 1 meter
distant from the machine or enclosure outline shall not exceed the
values specified in Clause 2.2.1.6, at 100 % Rated Output.
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VIETNAM ELECTRICITY I TEPSCO o MON THERMAL PQ!R PLANT
:A; \:16.2.2 .4 Absorbing Svstern j
7 J* / .0)
(a) The flue gas from the electrostatic precipitator (ESP) shalI
be directed thro'flue to the absorber module for removal of sulfur
dioxide. The absorber mod.t:e shall consist of an absorbing section
and a mist eliminator section. The flue gas shall be induced by the
booster fan located downstream ofthe absorber and the GGH.
(b) Sulfur dioxide removal shall be accomplished by the
absorbing slurry in the absorbing section. The sulfur dioxide shall
be captured by the absorbing slurry and finally converted to
calcium sulfate hydrate (CaS04 . 2H20). As the hot flue gas enters
the absorber and passes through the absorbing section, the flue gas
shall be quenched to saturation and sulfur dioxide shall be
removed. The flue gas shall pass through the absorbing section,
thereby assuring optimum liquid-gas contact, hence completing the
sulfur dioxide removal process.
(c) After completing the sulfur dioxide capture, the flue gas
shall flow into the mist eliminator located in the flue downstream
of or in the up most position of the absorber and the water
droplets shall be collected on the mist eliminator.
(d) The absorbing slurry shall be stored in the lower section of
the absorber module which is referred to as the absorbing slurry
tank.
(e) Fresh limestone slurry shall be added to the absorber in
order to control recycle slurry pH. The agitators ofthe absorbing
slurry tank shall make the solid float in the absorbing slurry.
(f) The sulphur dioxide removal process shall also involve an
enforced oxidation system. This oxidation system shall force the
calcium sulfite (CaS03' 112 H20) formed through the S02 removal
process to be oxidized to calcium sulfate (CaS04 . 2H20). One (1)
oxidation air blower having 50 % ofthe required capacity shall be
supplied and one (1) ofthe existing three (3) blowers shall be
employed for Unit No. 2. The capacity of each existing blower is 50
% of the required capacity. The oxidation air system for each Unit
Nos. 1 and 2 consists oftwo (2) oxidation air blowers.
(g) The drainage from the system shalI be collected in the
absorber area sump for Unit No. 2 and returned to Unit 2 absorber.
The absorber slurry shall be transferred to the existing blow down
tank and returned to the Unit No. 2 absorber by the exiting blow
down return pump when the absorber is required to be empty, such as
overhau l.
(h) All necssary provisions shall be made by the Contractor in
order to employ the
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VIETNAM ELECTRICITY / TEPSCO o MONTHER'AL POWER PLANT
eXlstmg eqUlpment.
(i) Specification ofthe existing common equipment The
specifications ofthe existing common equipment, for the Bidder s
reference, are as follows:
Equipment name: Quantity: Capacity: Head: Motor rating:
Equipment Name: Quantity: Capacity: Dimension: Accessory:
Equipment Name: Quantity: Capacity: Head: Motor rating:
No. 3 Oxidation Air Blower
5,000 m3Nfh (dry) 11 ,250 mmAq 200kW
Blow down Tank
1,864 m3
13,564ID x 14,151 H Agitator
Blow down Rtum Pump
180 m3fh 29mAq 30kW
As for the terminal points of the above, refer to Volume 11 of
14.
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/A
p --
j
c
)
N W O VIETNAM ELECTRICITY / TEPSCO 6.2.2.5 Gvpsum Dewatering
Svstem
(a) System flow
(i) The gypsum dewatering system shall consist of a hydroclone,
a filter feed tank, filter feed pumps and a vacuum filter train.
The vacuum filter train consists of a vacuum filter with associated
auxiliary equipment, a reclaim water tank, a reclaim water pump and
a chloride purge pump mainly.
(ii) One (1) hydroclone, one (1) filter feed tank, filter feed
pumps and auxiliaries shall be supplied for Unit No. 2. Two (2)
existing vacuum filter trains shall be used for Unit Nos. 1 and 2
commonly, but isolated from each other while two (2) Units in
operation simultaneously. A portion of the absorbing slurry in the
absorber module shall be fed to the hydroclone to control the
absorbing slurry tank level and slurry concentration. The underflow
of the hydroclone shall be fed to the filter feed tank. A part of
the overflow of the hydroclone shall be drawn to the existing
sludge storage basin in the waste water treatment facility via the
existing FGD waste water transfer system.
(iii) The filter feed pump shall transfer the slurry from the
filter feed tank to either of the existing two (2) vacuum filter
trains. The slurry is dewatered by the vacuum filter. The dewatered
byproduct gypsum is discharged to the existing gypsum conveyor and
transferred to the storage area in the gypsum dewatering and
storage house.
(iv) The filtrate from the vacuum filter is withdrawn to the
filtrate rceiver by th vacuum pressure induced by the vacuum pump.
The filtrate is withdrawn from the filtrate receiver to the reclaim
water tank by the filtrate pump.
(v) The reclaim water shall be fed to Absorbent
MillingIPreparation System by the reclaim pump and discharged to
FGD waste water receiving tank from by Chloride purge pump. Unit
No. 1 is with provided three (3) header pipes to separate the
reclaim water of each vacuum filter train for Unit Nos. 1 and 2,:
Pump suction header pipe for a1l pumps which connects with the
reclaim tanks Pump delivery header pipe for reclaim water pumps
Pump delivery header pipe for Chloride purge pumps Unit No. 2
piping shall connect with the above header pipes. The relaim water
shall be fed or discharged as one for U nit Nos. I or 2
respectively from the rclaim water tanks through the header pipes
by the valve operation.
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
(vi) In the event of failure of the vacuum filter train in
service due to some trouble or in case of maintenance, the spent
slurry produced by the absorber module is transferred to the
blowdown tank and stored tentatively.
(b) Vacuum filter train
(i) The existing two (2) vacuum filter trains are used for Unit
Nos. 1 and 2.
(ii) The accessory of the gypsum cake washing is provided for
the vacuum filter.
(iii) The water in the slurry is removed by the vacuum system.
The filter cloth restrains the cake while aliowing passage of the
water and air. The filtrate drains into the filter media and then
into the filtrate receiver where the air is separated from the
filtrate. The vacuum pump with a liquid seal ring is provided to
create the necessary vacuum.
(c) The sump common to Unit Nos. 1 and 2 has been installed. The
drainage from the system shall be collected in the sump and retumed
to the system adequately by the eXlstmg sump pumps.
(d) All necessary provisions shall be made by the Contractor in
order to employ the eXlstmg eqUlpment.
(e) Specification of the common equipment The specifications of
the existing equipment, for the Bidder s reference, are as
follows:
Equipment Name: Quantity: Filter area: Product humidity:
. Equipment Name: Quantity: Type: Capacity: Head: Motor
rating:
. Equipment Name:
No. 2 Vacuum Filter
14.9 m2
10wt%
No. 2 Vacuum Pump
NASH 4,320 m3N /h 68 kPa 90 kW
No. 2 Filtrate Receiver
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VIETNAM ELECTRICITY / TEPSCO o MON TlIERMAL POWER PLANT
Quantity: Capacity: 0.82 m3
Dimension 1 067 x 2,134 H
Equipment Name: No. 2 Filtrate Pump Quantity: Capacity: 25 m3fh
Head: 11 mAq Motor rating: 7.5 kW
Equipment Name: Separator / Cake Wash tank 2A / 2B Quantity: 2
Capacity: 0.18 m3
Dimension 406 x 1,435 H
Equipment Name: No. 2 Cake Wash Pump Quantity: Capacity: 3 m3fh
Head: 15 mAq Motor rating: 2.2kW
Equipment Name: No. 2 Reclaim WaterTa Quantity: Capacity: 105
m3
Dimension 5 500 x 5,950 H Accessorj: Agitator
Equipment Name: No. 2 RecIaim Water Pump Quantity: Capacity: 27
m3fh Head: 32mAq Motor rating: 11 kW
Equipment Name: No. 2 Chloride Purge Pump Quantity: Capacity:
4.5 m3/h Head: 13.7 m Motor rating: 4kW
Equipment Nam: Sludge Storage Basin
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
Quantity: Capacity: Dimension: Accessory:
Equipment Name: Quantity: Capacity: Dimension: Accessory:
Equipment Name: Quantity: Capacity: Head: Motor rating:
90 m3
6,000 x 6,000 x 3,000 H Agitator
Gypsum Dewatering Area Sump
25 m3
3,050 x 3,050 x 3,650 H Agitator
No.1 / No.2 Gypsum Dewatering Area Sump Pump 2 60 m3fh 18 .3 mAq
15 kW
As for the terminal points of the above, refer to Volume 11 of
14.
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL P"ER PLANT x
(a) The dewatered gypsum is discharged from the vacuum filter in
the dewatering area and transferred to the storage ara in the
gypsum dewatering and storage house.
(b) The gypsum storage house has a capacity of 5,000 tons
(equivalent to the capacity of gypsum transported ship) of gypsum
storage.
(c) The stored gypsum of 5,000 tons is transferred from the
gypsum storage house to the gypsum shiploader at the jetty by the
gypsum reclaimer and conveyor~ for eight (8) hours.
(d) The amount ofthe gypsum shall be measured with the gypsum
weighing measure.
(e) The conveyors, weighing measure and gypsum shiploader are
designed, manufactured and constructed to prevent ingress of rain
and emission of fine gypsum particles and to permit
interchangeability of parts and ease of access during inspection,
maintenance and repair.
(f) In case of supplying the by-product gypsum to domestic
consumers, 20 tons capacity trucks shall be used. Such a truck
shall be prepared by the consumers nominated by EVN.
(g) One (1) 2 ton capacity wheel loader is provided to scoop up
the by-product gypsum on the truck.
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VIETNAM ELECTRICITY / TEPSCO o 10N THERMAL POWER PLANT
6.2.2.7 FGD Make-up Water Supplv Svstem
(a) The clarified water is used for FGD make up water system.
The clarified water is supplied from the existing clarified water
receiving tank to the existing FGD make-up water tank by the
existing FGD mce-up water transfer pumps.
(b) The FGD make-up water is supplied from the existing FGD
make-up water tank by the existing two (2) FGD make-up pumps. The
necssary piping shall be provided to supply the water to Unit No. 2
FGD equipment.
(c) The mist eliminator wash water is supplied from the existing
FGD make-up water tank by the existing two (2) mist eliminator wash
pumps. The necessary piping shall be provided to supply the water
for the mist eliminator wash.
(d) Specification of the existing equipment The specifications
of the existing equipment, for the Bidder s reference are as
follows:
Equipment Name: Quantity: Effective Capacity: Dimension:
. Equipment name: Quantity: Capacity: Head: Motor rating:
. Equipment name: Quantity: Capacity: Head: Motor rating:
FGD Make-up Water Tank
1,323 m3
15 510x 9,190H
FGD Make-up Water Pump 1A/ 1B 2 140 m3fh 48.8 m 55kW
Mist Eliminator Wash Pump 1 A / 1 B 2 95 m3/h 67m 37kW
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VIETNAM ELECTRJCJTY / TEPSCO o MON THERMAL POWER PLANT
shall not effect on the existing equipment and structures or
minimize the effect on them and shaIl not disturb the operation of
the existing equipment.
(a) FGD electrical and control building The control system and
related equipment shall be installed on 1st floor in the existing
electrical and control building. The electric system shall be
located below the control system floor. As for the details, refer
to Volume 3 of 14.
(b) Void
(c) Limestone ball mill house The roofhas been provided over the
ball mill to enable the milling system to function even under
inclement wcather conditions. The crane has been provided for the
maintenance of each ball mill as follows: Capacity: 3 tons Span:
7,600 mm Length ofRunway: 15,300 mm Hook path: 8,110 mm
As for the details, refer to Volume 3 of 14.
(d) Oxidation air blower house The roof has been provided over
the oxidation air blower to enable the air supply system to
function in inclement weather conditions. The crane has been
provided for the maintenance of the oxidation air blowers as
follows: Capacity: Span: Lenh ofRunway: Hook path:
4 tons 10,400 mm 23 ,700 mm
5,257 mm
As for the dtails refer to Volume 3 of 14.
(e) Gypsum dewatering and storage house The roof has been
provided over the vacuum filter to nable the dewatering system
to
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL PO'ER PLANT
function in inclement weather. The gypsum storage house and the
gypsum transportation facility are located below the vacuum filter.
As for the details, refer to Volume 3 of 14.
6.2.2.9 Void
6.2.2.10 Materials
(a) Materials of construction shall be cOITosion and erosion
resistant.
(b) Main piping with slurry shall be of carbon steel with the
rubber lining or FRP (Fiber Reinforced Plastic) or equivalent and
the tank shell shall be made of carbon steel with the flake resin
lining or equivalent.
(c) Materials of the flue and its intemal support shall be steel
with the flake resin lining or equivalent from the untreated gas
outlet of GGH to the treated gas inlet of GGH.
(d) Materials of the flue, its intemal support and damper
located in the range from the treated gas outlet of GGH to the
stack inlet shall be cOITosion-resistant steel.
6.2.2.11 Process Outline
(a) FGD system shall be designed in accordance with layout and
process flow diagram as shown in Drawing Nos. OM2FD-l 00 1 and
OM2FD-l 002 in Volume 11.
6.2.2.12 The Manzins for the Des $m Caoacitv and Pressure
ofEouioment
(a) The margins in design capacity and pressure shall be allowed
for, but not be limited to, the following;
(i) Booster fan The design capacity of the booster fan sha l1 be
not less than 1.1 5 times BMCR
gas treatment. The design static pressure shalI be not less than
1.25 times the pressure required
at BMCR.
(ii) Pump, GGH and Agitator The design perforrnance of this
equipment shaIl be decided taking into consideration the
performance deterioration due to erosion and cOITosion for each
mamtenance term.
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
6.2.2.13 Soecification ofMain Eauioment '^~
(i) Absorbing Section Quantity Materials
Absorbing Section
(a) Absorber module
One (1) per unit
Carbon steel + flake resin lining or equivalent
Spray Headers in Absorbing Section Stainless steel or
equivalent
(ii) Mist Eliminator Quantity One (1) per unit Type Horizontal,
vertical or equivalent Material Polypropylene or equivalent
(b) Absorber Recycle Pumps (if necessary) Quantity Four (4) per
unit (One (1) is a stand-by) Type of Pump Centrifugal Casing
Material Impeller Material
Carbon steel + rubber lining or equivalent Carbon steel + rubber
lining, duplex alloy or equivalent
(c) Oxidation Air Blower Quantity
Type ofBlower Casing Material Impeller Material
One (1) to be supplied newly (One (1) of the three (3) existing
ones also is for Unit No. 2.) Roots or equivalents Carbon steel or
equivalent, if necessary Carbon steel or equivalent, if
necessary
(d) Booster Fan Quantity Type
One (1) per unit Centrifugal
(e) Reagent Feed Tank Quantity Capacity Material
One (1) per unit Hold for fve (5) hours operation Carbon steel +
flake resin lining or equivalnt
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VIETNAM ELECTRlCITY I TEPSCO 0 MON THERMAL POWER PLANT
(f) Limestone Silo
(g) void
Quantity One (1) per unit Capacity Seven (7) days operating
demand (not less than
1,000 tons) for one (1) absorber module
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
6.2.3 Electrical Requirements
(a) Forrtlhe eeelectrlCca1 requllremmentstsofFGD SyfVolume 2
Clause 2.2.3 titled Electrical Works. Technical Schedules e FGD
Electrical equipment shall follow the format ofVolume 13 Schedule
13
6.2.4 C & 1 Requirements
(a) The control and instrumentation system shall be designed to
operate and control FGD system, fully and smoothly automatically
following the boiler operating conditions.
(b) The control and monitoring system for the FGD System shall
be provided in accordance with Volume 7 Clause 7.4.10, Clause
7.4.15 and Volume 2 Clause 2.2.3. Technical Schedules for the FGD
C&I equipment shall follow the format of Volume 13 Schedule
13.6.
(c) All necessary measuring and detecting devices required for
control and monitoring of the FGD plant shall be supplied and
installed.
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
6.3 TEST AND INSPECTION
6.3.1 General
(a) All costs required to caY out all tests to ensure the
satisfactory design, manufacture, installation, commissioning and
performance of his supply in accordance with the Specifications and
Standards shall be included in the Bid.
(b) The Contractor shaIl be responsible for the timely delivery
of the relevant and appropriate sections of Specification to
sub-contractors, if applicable, and the proper execution of all
tests on works and materials shall be supplied by sub-contractors,
wherever such tests are carried out, to the same extent as if the
tests on works and materials were carried out by the Contractor
himself.
(c) The cost of all tests and inspections, including any
repeated test or inspection carried out at subcontractors works
shall be included in the B id.
(d) The Contractor shall submit to EVN inspection and test
procedures covering aIl materials and equipment. Agreement shall be
established on the scope of inspection and tests to be witnessed by
EVN or his nominees before start of the work.
(e) If without giving necessary advance notice the Contractor
carries out any test requiring the witness by EVN, such tests shall
be deemed unsatisfactory and the concemed part of supply shall not
be accepted.
(f) Tests not requiring the witness by EVN shall b in any case,
notifid in advance. The Contractor shaIl then proceed with the
tests and shaIl submit reports to EVN.
6.3.2 Records and Certificate
(a) Thirty (30) days after completion of any test, triplicate
sets of all principal test records, test certificates and
correction and performance curves shaIl be supplied to EVN.
(b) These test records, certificates and performance curves
shall be supplied, whether or not those tests were witnessed by EVN
or his nominated Representative. Th information given on such test
certificates and curves shall be sufficient to identify the
material or equipment to which the crtificate refers and also bear
the contract reference title.
(c) Whn equipment has been tested, all test certificates shall
be compild by the
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
Contractor into volumes and bound in an approved form complete
wit1}iex and the copies ofeach volume shall be supplied to EVN.
.~
(d) The following records and certificates shall be submitted.
(i) Chemical analysis and mechanical propeies of materials (ii)
Heat tratment process certificates of forging (iii) Reports of all
required tests (iv) Type test certificates (v) Affidavit of
compliance stating that all materials and works supplied will
comply
or have complied with the applicable requirements of these
specifications.
(e) The Contractor shall make the following available to EVN
upon request: (i) Films of all radiographic examinations (ii) All
welding procedures and performance qualification certificates (iii)
All non-destructive test procedures
6.3.3 Worksbop Tests
6.3.3 .1 General
(a) Where applicable, tests must comply with the Vietnamese
regulations as included in Clause 2.2.1.1.
(b) Where no specific test is specified, then the various items
of plant, equipment and materials shall be tested in accordance
with the applicable standard, acceptable to EVN. Where no
appropriate standard is available, tests shall be caic out in
accordance with the manufacturers standard practice, subject to the
prior approval of EVN.
(c) All tests to be performed during manufacture, fabrication
and inspection shall be agreed by EVN prior to commencement of the
work. The Contractor shall prepare the details ofthe schedule and
submit these to EVN for approval. It must be ensured that adequate
relevant information on the design code/standard employed, the
manufacture/fabrication/assembly procedure and the attendant
quality control steps proposed are made available to EVN. EVN will
mark in the appropriate spaces his intention to attend or waive the
tests or inspections.
(d) EVN shall be notified of impending tests by the Contractor
sixty (60) days in advance, and the Contractor shalI prepare all
testing equipment and personnel for such tests.
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
(e) The subject items should remain available for inspection and
test up to minimum ten (1 0) days after the date ofwitnessing the
test unless otherwise agreed by EVN. Every facility in respect of
access, drawings, instruments and manpower will be provided by the
Contractor and his Sub-Contractor to enable EVN or his designated
representative to caY out the necessary inspection and testing of
the equipment.
(t) No equipment shall be packed, prepared for shipment, or
dismantled for the purpose of packing for shipment, unless it has
been satisfactorily inspected, or approved for shipment, or
altematively inspection has been waived.
(g) The extent ofworkshop tests and method ofrecording the
results shall be submitted to, and agreed by EVN in sufficient time
to enable the tests to be satisfactorily witnessed or, ifnecessary,
any changes ofthe proposed programme oftests to be agreed.
(h) AIl instruments and apparatus used in the tests shall be
subject to the approval ofEVN, and, if required by EVN, shall be
calibrated to an agreed standard.
(i) The cost of carrying out such calibrations shal1 be bome by
the Contractor in all cases.
(j) EVN reserves the right to visit the Contractors Works at any
reasonable time during fabrication of equipment in order to survey
the progress made.
6.3 .3 .2 Mechanical Works
(a) The Contractor shall carry out the following test in
accordance with the Standards and Specifications as included in
Clause 2.2. 1.1.
6.3 .3 .2.1 Tests on Materials
(a) Representative samples and mill certificates of all plates,
bars, pipes, etc., which form components of the plant shall be
tested and submitted as required by the relevant approved standard
or code or at the request ofEVN.
(b) AlI test pieces shall be prepared and supplid by the
Contractor at his own cost. If any test piece fails to comply with
the requirements ofthe specifications for the matrial in question,
EVN may rct the whole ofthe material reprsented by that test
piece.
(c) AII important forgings shall be xamined at the manufacturers
works by jointly EVN or his nominee together with the
representatives of the manufacturers during forging and heat
treatment.
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VIETNAM ELECTRICITY I TEPSCO o MON THERMAL POJJRPLANT
(d) The test shalI be conducted on the fo lIowing, but no be
limited to: (i) Fan Shafts
\ (e) The mill certificats shall be submitted for approval of
EVN on work
equipment ofthe fo lIowing, but not be limited to: (i) Absorber
(i i) Flue and Damper (iii) Structure and Reinforcing Bar (iv)
Valve (v) Piping (vi) Tank and Silo (vii) Rotating Equipment
6.3.3.2 .2 Ultrasonic Examination
(a) AlI tubes and pipes for pressure piping shall be
ultrasonically examined for detection of injurious defects before
fabrication is started.
(b) Tube and steel plate surfaces shall be free from mill
scales, etc., to allow a c1ear interpretation of ultrasonic signal.
If necessary, a suitable treatment of surfaces shall be
performed.
(c) Ultrasonic inspection shall be in accordance with Vietnamese
Regulation and/or ASME Section 11 Sa-655, ASTM E164-94a or
equivalent.
(d) Imperfections found by ultrasonic examination shall be
judged against the acceptance - rejection standards outlined in
ASME Code Section VIII Div.l , Appendix 12, paragraph 12.3 or
equivalent.
6.3 .3 .2.3 Radiographic Examination
(a) Radiographic examination shall be the main quality control
of welding; where not possible, other approved method shall be
applied.
(b) For all shop welded pas the following percentage of seam
shall be examined: (i) Pressure vessels : 25 %
(c) AlI pressure pas shall be tested in accordance with the
requirements of Vietnamese Regulation and/or ASlE U nfired Prssure
Vessel code or equivalent.
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VIETNAM ELECTRICITY / TEPSCO o MON THERlrlAL POWER PLANT
6.3 .3 .2.4 Hydrostatic Test
(a) Hydrostatic test at 150 % of the design pressure shall be
carried out for a period of 30 minutes or longer at the
manufacturer s factory on pressure vessels in accordance with
Vietnamese Regulation and/or the ASME Code or equivalent.
(b) AlI hydrostatic tests shall be carried out prior to surface
coating or painting and cast iron enclosures may be subjected to
hammering as required by EVN.
(c) Hydrostatic tests of equipment manufactured of austenitic
steel should be carried out using water having chloride content
ofless than 30 ppm.
(d) Anti-rust additives shall be used to prevent oxidation of
surfaces. As an altemative, the surface may be dried up upon
completion oftests.
6.3.3.2.5 Pipework
(a) The fabricated pipework shall be tested in accordance with
the standards as specified by ANSI. B31.1 /ASME B3 1.1 or
equivalent.
(b) Temperature records ofhot forming and heat treatment
operations shall be made, filed and submitted to EVN.
(c) The walI thickness of hot formed bends shall be checked by
ultrasonic method. Records ofthese shall be kept and made available
to EVN.
(d) Where random radiography is specified, this shall refer to
the final weld only at EVNs selection and discretion.
(e) For the purposes ofradiographic inspection, a root pass is
defined as the first complete weld run.
(t) AII piping not covered by 100 % radiography shall be tested
as follows. (i) Lined piping shall be tested for leak ofwater with
the f10wing water in the piping. (ii) Piping f10w without lining
shall be hydrostatically tested at 1.5 times ofthe design
pressure. (iii) Piping for air and gas f10w shall be tested with
pneumatic pressure.
(g) In addition to the NDT requirements stated in ANSI B3 l.l/
ASME 83 1. 1 paragraph
6-3-5
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VJETNAM ELECTRJCJTY ITEPSCO O MONTHERM'l._POWER PLANT \
136.4 or equivalent, the Contractor shall radiograph all butt
welds 0/ing over 50 mm in accordance with the requirements outlined
in the table belo 7
EEg
Auxiliary steam Soot blower steam
Root Pass Final Pass (After PWHT* where applicable)
None 10 % None 10 %
* PWHT : Post Weld Heat Treatment
(h) Examination shall be made on the entire weld. Percentages
refer to the total number of weld and shall be representative of
the range of sizes. The above requirements are applicable to both
site and shop welds.
(i) All nozzles, branch connections, butt welds and attachment
welds in alloy steel pipe shall be subject to magnetic particle or
dye penetrative inspection.
U) Magnetic particle inspection shaIl be carried out in
accordance with ASTM E709-95 or equivalent.
(k) When dye penetrative method is applied, it shall be
conducted in accordance with ASTM E165-95 or equivalent and
application directed by the penetrate manufacturer.
6.3.3.2.6 Pumps
(a) All pumps shall be tested in accordance wth the approved
standards. Prior to any tests, the Contractor shall submit a test
procedure showing the layout of the testing equipment with the
positions of pressure measurement points and f10w measuring
devices, for approval of EVN. In addition, the details of
calibration of the f10w measuring device, motor power vs.
efficiency curve, a specimen of the test record sheet and details
of the performance calculations shall be provided.
(b) The performance test shall be conducted over the fu Il
operating range of the pump. Curves indicating f10w rate vs. head,
f10w rate vs. power consumed, and f10w rate vs pump efficiency
shall be provided. In addition, the curve of f10w rate vs. NPSH
required shall be providd.
(c) On completion ofthe tests the Contractor shall submit a
report showing the test results obtained together with the curves
corrected to the site operating conditions.
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
6.3.3.2.7 Fans
(a) Booster fan shall be subjected to full performance test
including static and dynamic balancing which shall be witnessed by
EVN.
(b) The test shall be in accordance with the latest applicable
ASME test codes or equivalent.
6.3 .3 .2.8 Steel Structure
(a) Radiographic examination shall form the main quality control
ofwelding; where not possible, other approved method shall be
applied. The examination shall be applied to 25 % of all shop
welded parts for main structure.
(b) Dimension check for main structure shall be carried out.
6.3 .3 .2.9 Lifting Equipment and Cranes
(a) The Contractor shall caY out the tests as required by the
approved standards, to prove the capacities of cranes and lifting
equipment. Test certificates shall be submitted and shall include
the material Iist of equipment, welding record and non-destructive
test record for electricaI equipment, wire ropes, hooks, chain
blocks, shackles, runway beam, eye bolts and any other related
items which are provided.
(b) Upon completion of the tests, the equipment shall be clearIy
marked with the safe working load (SWL) and any other markings that
EVN may require.
6.3 .3.2.10 Insulation Material
(a) The Contractor shall provide the thermal conductivity test
repo for the last five (5) years applications ofthe product or
shall conduct the test ofthermal conductivity in accordance with
ASTM codes or equivalent.
6.3.3.2.11 Lining
(a) Alllined components ofthe plant shall be tested for proper
lining in accordance with the lining manufactures instaIlation
procedure and applied to the specified thickness oflining. At least
the spark test for the whole lined surface and random test
ofhardness shall be conducted.
6-3-7
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VIETNAM ELECTRICITY / TEPSCO
6-3-8
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
6.3.4 Test and Inspection at Site
6.3 .4.1 General
(a) All equipment and plant shaIl pass tests on site as required
by EVN to pro'v compliance with the specification independently of
any tests which may have already been carried out at the
manufacturer's works.
(b) The tests at site shall include, but not necessarily be
limited to, those specified in this sectln.
(c) In paicular all functional and pressure tests on fully
assembled and complete items of plant which have not been carried
out at the manufacturers works, shall be caied out on slte.
(d) The commissioning shall be carried out in accordance with
the requirements ofClause 2. 1. 11.
(e) The Contractor shall be responsible for all site inspection
and tests as required by EVN and for the providing of the reports.
Detailed proposal for all tests shalI be submitted to EVN for
approval.
(f) During the course of erection ofthe plant, EVN is to have
access to the plant and/or its components for inspecting the
progress of the work and checking its accuracy to any extent that
may be required.
(g) The Contractor shalI provide alI temporary scaffolding,
ladders, platforms with adquate and safe flooring, and handrails
essential for proper access of EVN or his nommees to caY out
inspections.
(h) The Contractor shall also provide all personnel, materials,
and instruments and other resources necessary for such tests.
6.3 .4.1.1 Inspection and Test Equipment
(a) The Contractor shaIl supply the instruments for tests and
inspection of totaI plant to E'N at site (refir to Clause 5.3
.4)
(b) Before the PAC, the above instruments shall be handed over
to EVN in proper working ordr.
6-3-9
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\ VIETNAM ELECTRICITY / TEPSCO O MON:~'I1AL POWER PLANT
;:~h ,Y:':// (c) Where necessary, specialized training for
operators for any in~nents above shall be
provided and the cost associated with such training shall be
included in the Bid.
(d) It is the Contractors responsibility to provide certified
calibration curves for instruments, comprehensive operating and
maintenance instruction manuals, electrical circuit diagrams,
maintenance tools and spare parts catalogue. AIl documents shall be
in clear, simple and correct English.
6.3 .4.1.2 General Inspection Procedure
(a) Equipment Arrival at Site Contractor shaIl notify EVN of
arrival of equipment for any physical inspection.
(b) ErectionlInstaIlation of Equipment (i) General
Inspection
During erection stage, EVN wiII inspect erection/instalIation of
equipment generaIly from the foIIowing aspects.
- Any non-conformance - Workmanship - Materials used are of
approved type/quality.
(ii) Official Inspection by EVN Inspection on major equipment
which is listed by EVN and the Contractor wilI be made by EVNs
inspection staff officially in accordance with site quality control
(QC) procedure submitted by the Contractor and approved by EVN and
the steps given below shalI be foIlowed.
Step 1 Request for Inspection/ Attendance (Refer Note * 1)
Note * 1
The prescribed form "Request for Inspection/ Attendance" shaIl
be submitted by the Contractor to EVN twenty four (24) hours prior
to the inspection and include the following information.
i) Location ofWork to be inspected ii)Purpose of inspection iii)
Relevant drawings, sketches, calculation, etc iv)Reference No. of
applicable document
Weekends, public holidays and times when EVN office is
officially c10sed shall be not considered as notice .
AIl requests shall be registered by EVN with time/date ofreceipt
stamped on each request.
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
Step 2 Inspection Check Sheet Upon approval of the Step 1, EVN
and the Contractor wiIl inspect e item~ in accordance with the
inspection check sheet prepared by the Contractor which wiIl be
handed over to EVNs inspector at site. After inspection, both
parties will endorse on the above sheet as an evidence of
inspection. Should there be any discrepancy, another similar
inspection will be called for.
Step 3 Verification Certificate Upon completion ofthe inspection
of each item, the inspection results shall be summarized in the
verification certificate and reviewed by EVN.
Step 4 Conformity Certificate Upon completion ofthe inspections
of all, all the inspection results will be summarized in the
conformity certificate and reviewed by EVN.
6.3 .4.1.3 Painting Inspection Procedure
The painting work shall be carried out as specified in Clause
2.2. 1. 13 and inspected in accordance with the following
procedures.
(a) Submission of check documents to EVN The Contractor shall
submit the following documents to EVN for approval.
(i) Colors items not specified in the EVN Standards (ii) A list
of paint suppliers (iii) A list of applicators (iv) A quality
assurance program (v) Painting methods for corrosion resistant
paints for places exposed to corrosive
conditions
(b) To check all paints and cleaning materials which are to be
of approved quality
(c) To check coats which are to be produced by same manufacturer
or to be of the same quality
(d) To check the cleaning works to be executed in accordance
with the approved quality assurance program
(e) To check the painting works to be executed in accordance
with the approved quality assurance program
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VIETNAM ELECTRICITY / TEPSCO
(f) Random check ofpaining coat thickness
(g) To check finish to satis:ty EVN Standards (i) Color codes to
be in accordance with EVN s color code standard or that
approved
byEVN (ii) Smoothness of finished surface (i ii) Rests ofthe
high voltage sparking test on the surfaces to be exposed to
corrosive
conditions
6.3 .4.2 Mechanical Works
6.3.4.2 .1 Welding and Welding Documents
(a) Welding works carried out by the Contractor shaIl be
inspected by EVN in accordance with the requirements of Clause 2.
1. 10 and the further requirements given below.
(b) In cases where the Contractor employs subcontractors who are
to caY out certain site works, e.g. non-destructive testing (ND it
is stiIl the Contractor's responsibility to prepare such quali
control documents related to the site works. Furthermore, it is
specificaIIy requir'd that such documents shall be, after the
Contractor obtains the necessy approval by EVN, forwarded to the
subcontractors for their compliance. It is the Contractors
responsibility to retrain, if necessary, his subcontractors'
personnel anor procure additional equipment in order to meet the
requirements ofthe approved quality control documents.
(c) Before commencement of the site welding, the Contractor
shall prepare the following documents and submit them to EVN at
site for approval.
(i) Welding Procedure Specifications (WPS) and Procedure
Qualification Records (PQR)
A Il welding on pressure parts or non-pressure pas shall be
carried out in accordance with the approved qualified WPS. Th
Contractor shall compile all the WPS and their respective PQR to be
used for site welding in one volume and submit them to EVN for
approval at site before commencement ofwork. EVN shall accept any
or all the WPS without prejudice to his rights to call for
re-qualifications of any or all of the WPS at site, should it be
deemed necessary. If such a pre-qualification is required, the WPS
test shall be conductd at no extra cost to EVN, based on agreed
national or international standards.
6-3-12
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
(ii) Welders Qualification Test Procedures The Contractor shall
prepare a Welders Qualification Tests Procedures summarizing the
different types of site welders tests. Such test procdures shall be
based on the agreed standard. The number and type of tests required
shaIl be determined by the essential parameters such as:
- Welding process - Material - Filler material - Pipe or plate -
Size - diameter anor thickness - Position - Type of joints - butt
and/or fillet joints
Each test procedure shall be specified in detail to include, but
not be limited to information on specimen size, methods oftests:
non-destructive and/or destructive, assessment of test results, and
rejection and acceptance criteria.
The Contractor shall prepare weld maps of all the joints to be
welded at site. These weld maps shall be prepared for piping. The
weld map shall show diagrammatically the location of each joint,
the identification numbers of the joints (each joint shall have its
own unique number), the dimensions and edge preparation of each
joint and the WPS applicable. The weld maps shall be submitted to
EVN at site for approval.
(iii) Weld Application Table It is mandatory that the Contractor
prepares a Weld Application Table before commencement of work. A
Weld Application Table is a summary of the requirements of each
individual joint to be welded. An example of the format of a Weld
Application Table is as below.
(Example)
System : MAIN STEAM PIPE
Joint No. Base Metals
Pipe Size, dia. x t (mm) WPSNo. PQRNo.
MSF-l SA 335 P22 SA217 WC9 406.4 x 67 55TA-SRl P-55TA-l
6-3-13
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VIETNAM ELECTRJCITY / TEPSCO
Filler Metal : Spec. No.
Root Run
Subsequent Runs
Preheat Temp. (oC) PWHT Procedure No. Soaking Temp. e C) Soaking
Time (Minutes) Heating Rate (OC/min) Cooling Rate eC/min) NDT
Required VIIPT RT MT UT Remarks
100 % 100 % 100 % 100 %
(iv) Non-Destructive Testing (NDT) Procedure All NDT to be
carried out at site shall follow the approved procedures. Such
procedures shall not be just a reference to or a copy ofthe agreed
Standard, but shall be tailor-made, taking account of the actual
works to be carried 0t at site such as the availability and type of
equipment at site and the skill of NDT operators employed. The NDT
equipment shall be ofwell-known make and comply with the
requirements of the approved Standards.
The NDT operators shall be certified in accordance with a
Certification Scheme. The Certification Scheme shall be approved by
EVN. Even if an operator has been certified, EVN has the right to
conduct practical tests. Such tests shall be carried out by the
Contractor at no extra cost to EVN.
(v) Heat Treatment Procedures For the purpose of this Clause,
heat treatment incJudes post fabrication heat treatment, pre-heat
treatment and post-heat treatment of welding. The Contractor shall
prepare Heat Treatment Procedures based on the agreed Code and
Standard and/or Manufacture s provn practice. The procedures shall
not b just a reference to or a copy of the agreed Standard, but
shall be tailor-made to suit the site conditions: type of joints,
accessibility, type and availability of equipment at site, and
skill ofheat treatment operator employed.
6-3-14
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VIETNAM ELECTRJCITY / TEPSCO
The procedures shaIl cover the fo lIowing items: method (s)
ofheating
o MON TlIERMAL POWER PLANT
type of equipment, temperature recorders, thermocouple, wires,
heating elements
calibration of temperature recorders and thermocouple wires;
frequency of calibration
calibration cente methods of calibration number of joints to be
heated at the same time number ofthermocouples per joint methods of
attachment of thermocouples to joints locations of thermocouples on
the joints number ofheating elements per joint size ofheating
elements methods of securing heating elements to joints methods of
prevention of direct heating(shorting) ofthe thermocouples
undemeath the heating elements : the use ofhigh temperature
putty type of insulation blankets size of insulation blankets :
width x length x thickness coverage of insulation blankets over
heating elements methods of securing blankets over joints emrgency
procedures : what to do if there is a temporary power cut or a
permanent power cut or shorting of the thermocouple wires,
additional precautions to take during rainy weather: water chilling
of joints while heating/soaking/cooling
restrssing of a joint : aHwable friquency of stress exertion the
use of portable hardness-tester to check efficacy ofheat treatment
confirmation of the efficacy of the heat treatment procedures by
in-situ metallography
stamping/recording ofthe heat treatment recorders' charts:
information needed and format
(vi) Repair Procedures The Contractor shaIl prepare a Repair
Procedure based on the fabricationlwelding requirements of this
Specification and approved Standards. The procedure shall be
prepared in detai! enough with regard to equipment to be used,
methods of repair, acceptance/rejection criteria, inspctions
required, etc., taking account of the site constrants.
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL PO:vER PLANT
(vii) Other Documents The Contractor shall submit to EVN one (1)
copy of other reletdocu such as mancturer's practice, technical
pape where such documents .;~ng referred to in his site welding
documents. '. "\:\
6.3.4.2.2 Site Welding Control
(a) In order to monitor and maintain welding quality at site,
the Contractor shall establish in his site organization an
independent Quality Control Section, whose function would be solely
to enforce the Contractors field quality assurance programme and
the site quality plans.
(b) Site Quality Control Section The Contractors Quality Control
(QC) Section shall be headed by an experienced Quality Control
Engineer. He shall be assisted by at least one Welding Supervisor.
The Section shall be an independent one in the Contractor s Site
Office and shall be under control of Contractors Company Quality
System Management.
The Contractors QC Section shall keep close communication with
EVN personnel in charge of Quality Assurance/Quality Control.
(c) Control ofWelders The Contractor shall employ only
experienced welders. However, all welders, with or without previous
qualifications, shall be tested to meet Test Procedures. Holders of
current welding certificates from the relevant Vietnamese authority
shall not be exempted from the test. Howver EVN site ce may, at his
discrtion aIlo these welders to work if they can demonstrate their
skill on five (5) production joints, of which the sizes and
locations shall be selected by EVN, without any defects as revealed
by visual inspection and radiography. The same rule shall apply
bona fide to welders from the Contractors manufacturing works.
All welders qualification test shall be conducted, at the
Contractors expense, and witnessed by EVN who makes final decision
of the suitability of the welders.
In case that Vietnamese legal requiremnt asks the welders to be
registered in the relevant Vietnamese authority and welders
qualification test be conducted in their
mspctor s presence, it is the responsibility of the Contractor
to aange for the Inspectors attendance.
The Contractor shall monitor the performance of his welders
throughout the project.
6-3-16
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
EVN may require a welder to be re-qualified ifEVN deems the
skill ofthe welder has deteriorated, and the Contractor shall
promptly remove the said welder from the job.
At the discretion of EVN, the re-qualification test may be
conducted in the same manner as the original one or in a similar
form. If a welder produces bad welds~ for example, in the spray
pipe region, the re-qualification test may not be just welding a
single test piece but may be welding five pipes (of which size is
equal to spray pipe size) and in the similar position. All costs of
re-qualification tests shall be bome by the Contractor.
(d) Control of Welding Activities The Contractor shall at all
times control its welding activities in a manner whereby the
quality requirement of its Field Quality Assurance Programme (FQAP)
is never compromised, but at the same time no delay to the Welding
progress is experienced. The Contractor shall draw up a working
procedure to accommodate EVN participation at Site in accordance
with the following:
Activities EVN Scope (i)Material Receiving checks 100 % Checking
(ii) Cleaning of Components Spot Checking (iii)Alignment of
component 100 % Checking (iv) Fit-up Checks 100 % Checking. The
Contractor shall not proceed until
EVN approval is obtained. (v) Issue ofElectrodes Spot
Checking
lFiller material (vi) Inspection during Spot Checking; but EVN
shall witness the sta of
actual welding welding at new areas or systems. vii) Visual
Inspection after 100 % Checking. The contactor shall not proceed to
NDT
welding or other work until EVN gives approva l. (viii) NDT
before PWHT AIl NDT shall be witnessed by EVN. For radiography,
EVN may not be present at all times. However, joints shall be
selected by EVN, and the radiographs together with their
Interpretation Reports shall be submitted to EVN. EVN decision on
the acceptabili or otherwise, as per the agreed Standard, of the
radiographs and/or the joints shall be final and binding on the
Contractor.
(ix) PWHT Spot Checking during PWHT. The Contractor shall submit
to EVN each joint PWHT Chart. The chart shall be stamped with the
relevant data.
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VIETNAM ELECTRICITY / TEPSCO O10N THERMAL POWER PLANT
(x) NDT after PWHT All NDT ancr PWHT shalla bbeo w; scd by EVN
in a manner similar to Item (viii)
(xii) Hydrostatic Test 100 % Checking Requirements that the
hydrostatc test shalI be witnessed by the Inspector from the
relevant Vietnamese authority, the Contractor shall aange for the
said Inspectors attendance. All costs required only for conducting
such tests shall be bome by the Contractor.
In all cases, the Contractor s scope shall be 100 %. In case
where EVN participation is also 100 %, such inspection may be caied
out jointly at the same time when the Contractor carries out his
inspection. However, EVN may insist that the Contractor carries out
his inspection first and correct whatever defects found before
caIling for EVN participation.
The Contractor shaIl submit a daily report on welding works
indicating the distribution of welders, the number and
identification of joints welded, and the number and identifications
of joints to be subjected to NDT and PWHT.
The Contractor shall prepare all check sheets for the
inspections, and the check sheet format shaIl be approved by EVN at
site. Such check sheets must be signed by the relevant pties
immediately after the inspection. The Contractor shaIl submit to
EVN these check sheets bound in volumes, appropriately titled when
the project is completed.
The radiographic films, after review by EVN at site, shall be
retumed to the Contractor. The Contractor shall then classify the
films, put them in appropriately labeled boxes and store them in
cIean, dry, pest-free air-conditioned room. The Contractor shall
keep the films in such good conditions for the determined years
after the completion ofthe project. EVN shaIl have access to these
films at any time during the storage period.
(e) Control ofWelding Consumables The Contractor shall follow
the manufacturers' recommendations in storage and handling of all
welding consumables.
It is Contractors responsibility to confirm the purity ofwelding
gases. The Contractor shall have accurate instruments for
measurement of gas tlow and oxygen concentration.
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VIETNAM ELECTRJCITY / TEPSCO o MON THERMAL POWER PLANT
The Contractor shall only bring to site welding electrodes and
other filler materials complying with the approved WPS.
Each consignment ofthese welding consumables to site shaIl be
accompanied with the manufacturers mill certificates. The
Contractor shall not change the brands of the welding consumables
without prior approval ofEVN.
The Contractor shall provide electric ovens with suitable timers
and temperature indicators for the purpose of preheating the
welding electrodes before issuing to the welders. The quantity of
electrodes issued shall only be for four (4) hour use. The
contractors shall provide his welders with electrically heated
quivers to cay the electrodes to working areas. Furthermore, in
order to ensure compliance with the requirement that the quantity
of electrodes for only four (4) hour use is issued at one time, the
Contractor is required to provide two (2) colour-coded quivers to
each welder, such that, for example, only red quivers are used in
the morning and blue ones in the aftemoon (after lunch). It is the
strict requirement of this Specification that the Contractor
ensures that his welders return unused welding electrodes to store
after every four (4) hour shift and fresh electrodes for use in the
next four (4) hours is issued in diffrent quivers.
The Contractor shall establish and follow diligently an
Electrode Record Procedure whereby the amount and type of
electrodes issued to each welder at every issue are recorded in
either a Record Book or Card. Such record shall be made available
to EVN at site for scrutiny whenever requested.
F or fiHer matrials to be usd in TIGwlding process, the
Contractor shall ensure that the filler materials are clean, dry
and rust-free. They shalI also be positively identified either by
using tags, colour codings, or both. Alternatively, their
specification numbers shall be stamped on the rods at regular
intervals in such a manner that when cut in shorter len!hs such
stamps will still be visible. The f1ags or colours to identity rods
shall also present in full lenh. The filler materials shall be
carried to work-areas in suitable containers.
(f) Control ofNDT The Contractor shall be responsible for
controlling all NDT activities under his contract, even when he
sub-contracts the job to a NDT specialist company.
The Contractor shall ensure that his NDT equipment are reliable,
modern, calibrated and comply with all relevant requirements ofthe
agreed Standards.
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL PV,wER PLANT
The Contractor shalI employ only mature and experienced NDT
ope'r#rs. The Contractor shalI ensure that the NDT operators hold
current and relevant
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VIETNAM ELECTRJCITY / TEPSCO o MON THERMAL POWER PLANT
be also inspected by the local authority.
(b) Lined piping Lined piping shall be tested with the f10wing
water in the piping.
(c) B uried Pipework Notwithstanding any test perfonned at
works, the pipework coatings shall be tested in accordance with the
mentioned below.
The protective coating shaIl be inspected visually while being
applied.
After priming, coating and mapping operations have been
completed, the surfaces shaIl be tested with an approved electrical
thickness detector. Any missed spots in the coating shaIl be
repaired with overwrapping.
6.3 .4.2.5 Tank and Silo
(a) Limestone Silo The limestone silo shaIl be subjected to
vacuum test in accordance with applicable standard. Equipment used
for the testing shall be subject to the approval by EVN.
(b) Slurry and Water Tanks AIl ta(s operating at atmospheric
pressure shalI be tested for at the minimum 30 minutes by fiIIing
to maximum level and being subjected to an additional hydrostatic
pressure of 15 mm Aq.
6.3.4.2.6 Rotating Equipment
(a) Rotating equipment such as fans, milIs, conveyors and pumps
shaIl be subject to a running test prior to commissioning for
checking correct rotation, vibration and noise.
(b) Sound pressure and vibration levels emitted from equipment
shaIl be measured in accordance with approved codes and standards
to demonstrate compliance with the reqUJrements.
6.3.4.2.7 Lifting Equipment
(a) After the works have been completed, all lifting equipment
shall be tested to confinn correct operat lOn.
6-3-21
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VIETNAM ELECTRICITY / TEPSCO o MON THERMAL POWER PLANT
(b) Subsequent to the satisfactory completion ofthe above tests,
the tests shall be repeated in the presence of Authority in
Vietnam.
t/ (c) The Contractor shall be responsible for preparing test
blocks for the 6.3.4.2.8 Functional Tests
(a) All installed equipment shall be tested for correct
operation and functioning.
6.3 .4.2.9 Safety Valve Setting
(a) It shall be confirmed that the settings of all safety valves
are properly made as required by ASME Code or equivalent.
(b) All safety valves shall be gagged except the one to be
set.
(c) For the auxiliary steamlsootblower safety valves, the
setting will be made manipul