condenser erection

Station: NTPC- Rihand

BHEL Ref No: PW/TSX/RIT/TUR-PR/001/REV00

Plant area: CONDENSER

Document- Type ERECTION MANUAL

Revalidated document prepared based on doc, BHEL/PSNR/TSX/VSTPP/TA-08 –for internal use.

POWER SECTOR-WESTERN REGION TECHNICAL SERVICES NAGPUR-440 001

1

Issued to Date of Issue TN VARDARAJAN/ CM/RIHAND

Prepared By Reviewed by Approved by

Issued by

O. D.SHARMA D K SHRIVASTAVA ML SAH B.P.RAO Sr.Mgr./ TS/PSWR SDGM/TSX/PSWR GM/TSX & SAS/PSWR Head/TSX

ERECTION MANUAL FOR CONDENSER

RIHAND # 3&4 - 500 MW







2

PREFACE

The erection manual of condenser for Rihand 3&4- 500 MW project

provides guidelines for erection of Condenser. The procedure may require

some minor alterations at site to meet the local site conditions.

BHEL reserves the right to adopt alternate procedure, if necessasity

arises.

Feed back and suggestions from the users/task performers are solicited

for further improvements.







3

CODIFICATION FOR

INSTRUCTION NUMBER







4

The following codification system is used for numbering of instructions and the codification of Log sheets is as per FAQ document. XX X XX XX XX X Alpha Numeric Numeric Numeric Numeric Alpha Type of Instruction System Instuction No.

System Designation Rating of Main Equipment Type of Manual

Product Code 1.1 Product Code B - Boiler BA - Boiler Aux. T - Turbine TA - Turbine Aux. G - Generator GA - Generator Aux. P - Power Plant Piping CI - C&I







5

1.2 Type of Manual 1. - Erection 2. - Commissioning 3. - Services 1.3 Rating of Main Equipment

01. - 200/210 MW

02. - 120 MW

03. - 110 MW

04. - 60 MW

05. - 30 MW

06. - 100 MW

07. - 235 MW

08. - 500 MW -KWU Design




12. - 70MW -KWU Design

13. - Industrial Units

14. - 210 MW -Tower Type Concrete Pylem

15. - 210MW -Tower Type Steel Structure

16. - 500MW -Tower Type Once Through

17. - 250MW

18. - CCP







6

1.4 System Designation 01 - General Instuction

02 - Technical Data

03 - Erection Strategy - Condenser

04 - Erection Procedure- Condenser

1.5 System Instuction No. 01 - General Description

02 - Technical Data


04 - Erection Procedure - Condenser

1.6 System Instruction No. 01 - General Instruction

02 - Technical Data


04 - Erection Procedure - Condenser

1.7 Type of Instruction G - General T - Technical L - Log Sheet

C - Check List







7







8

INDEX S. NO. DESCRIPTIONINSTN NO. 1. GENERAL DESCRIPTION TA1-08-0101G 2. TECHNICAL DATA TA1-08-0202G 3. ERECTION STRATEGY TA1-08-0303G 4. ERECTION PROCEDURE TA1-08-0404G 5. LIST OF DRAWINGS







9

GENERAL DESCRIPTION







10

1.0 INTRODUCTION

The condenser is a box type construction with divided water box

design double flow; two pass which facilitates the operation of one half of

the condenser while other half is under maintenance. The steam space is

of rectangular cross-section with integral air-cooling section from where

air and non–condensable gases are drawn out with the help of air

evacuation equipment.

2.0 CONSTRUCTION

2.1 The surface condenser is mounted on spring supports. The

condenser is welded with the exhaust hood of the low-pressure turbine.

The tube plates are welded with the water chambers. Condensers are

provided with domed shape water box. The condenser tubes are

supported within the condenser shell by tube support plates, which are so

spaced that the vibrations of the tubes are prevented under normal

operating conditions. The condenser is installed in such a way that all

condenser tubes are drained automatically into the condenser water

boxes.

2.2 NECK

Condition has been provided with an extension suitably to connect it to

the turbine exhaust opening. Adequate internal clearance is provided. The

rigid construction results in a sound-condenser combination for trouble

free operation.







11

2.3 TUBE LAYOUT

The tube layout is of modular type reinforced having properly sized tube

bundles. Steam lanes are designed from thermo-hydraulic considerations

resulting into better heat transfer, effective deaeration and minimum

pressure drop. Air-cooling zone is suitability located for effective venting.

2.4 WATER BOX

The water boxes of the condenser have been designed for smooth entry

and uniform distribution of cooling water to all the tubes. The water boxes

are removable type and have been provided with necessary hinged

manholes for easy access to the interior for inspection. Each water box

has been provided with a vent and drain connection. The circulating water

connections of adequate size have been provided with water boxes.

Safety guards have been provided to protect the operating personnel

from failing during inspection or maintenance.

2.5 HOT WELL

Hot well (of adequate capacity) is divided longitudinally for detecting

contamination of the condenser half. Suitable manholes are provided in

each of the hot well sections for easy access and inspection. The

condensate produced in the condenser & drains entering through flash

vessels collect in the hot well from where the pass to the condensate

pumps.







12

TECHNICAL DATA







13

STEAM SURFACE CONDENSER 1. Manufacturer - BHEL / HARDWAR 2. No. of passes -Two 3. Tube length between tube plates (mm) -14630 4. Total no. of tubes -24398 5. Tube outside diameter

and thickness (mm x mm) -OD 31.75 X 0.7112 mm thick. Top 2 rows – 0.889 mm thick.

6. Tube material -Welded stainless steel

ASTMA249, TP304 7. Water box design pr. Kg/cm (g) -5.0 8. Water test pr. Kg/cm2 (g) -7.5 9. Duration of test (min) -30

10.Shell design pr. Kg/cm2 (abs) -Full vacuum and 1.08 kg/cm2g

11. Shell test pr. Kg/cm2 (abs) -Water fill up to LPT

blade tip 12. Duration of test hrs. -24 (min) 13. No. of support plates -2 x 18 14. No. of spring elements - 36 15. Method of supporting the condenser. -Spring mounted 16. Type of condenser neck to LP turbine casing -Welded joint 17. WEIGHTS (approx)







14

a). EMPTY WEIGHT i. Condenser (without spring) with LP heater no.1 - 710,000kgs. b). OPERATING WEIGHT Condenser + LP heater no.1 - 1260,000 kgs. c). FLOODED WEIGHT Water filled up to LPT blade tip of last stage - 2100,000 kgs. with CW side and LP heater no.1 d). Weight of cooling water - 448,000 kgs. e). Weight of spring elements - 32,000 kgs. Ref: Drg No: - 0-160-10-700 43c 80 Rev 02 Condenser assembly. f). Weight of single heaviest part (front water box) - 30,000kgs.







15

ERECTION STRATEGY







16

ERECTION STRATEGY The condenser to be assembled and erected at Rihand 2 x 500MW is

supplied in various components from the works.

* Loose parts mainly comprise of the following: i) Bottem plate. ii) Turbine & Generator side wall plates. Iii Dome walls. iv) Front water chambers and Rear water chambers with tube plates. v) Tube support plates 2 x 18 nos. vi) Hot well. vii) Spring elements - 36 nos. viii) Steam throw devices - 2 nos. ix) Condenser tubes. (I) PREPARATION FOR ERECTION

1. Approach to TG hall should be suitable for movement of heavy

equipment to transport the components.

2. The EOT Crane should be available covering the complete

condenser area.

3. Sufficient area should be available for pre-assembling preferably on

the turbine floor.







17

4. Power source of 200 Amps should be available.

(II) TOOLS & PLANTS -All normal small tools should be available. -Apart from this the following shall be required during erection: -

1. Welding Generators 4 nos. 2. Chain pulley blocks 5T 4 nos.

3. Slings (40mm) 4 nos.

4. Angle grinders 1 set

5. Tube expander with tools 2 nos.

6. Tube cutting bits 2 sets

7. Trailer with pulling unit Sufficient Qty.

8. Trailer with pulling unit for tubes 1 no.

9. Rolled steel section for pre –assy. 1 no.

10. Wooden planks for condenser covering. 1 MT App.

11. GI / Black sheet for condenser covering Sufficient Qty.

12. UV Lamp 1 set

(III) PREASSEMBLIES a) BOTTOM PLATES Depending on site conditions, the preassembly of the plate will be

done.If the foundation and approach is ready then it would be directly







18

assembled on the foundation. However, if the foundations are not

ready it would be assembled separately outside. The bottom plate is in

four parts and two of them will be pre-assembled outside. On each

half the hot well and the spring supports will be welded/tacked. As the

opening on the foundation is big enough the preassembled bottom

plate can be lowered flat without any risk.

b) SIDE WALLES Both sidewalls are carrying in four parts. Two joints would be welded

outside the foundation.

c) WATER CHAMBER / BOXES

The assemblies of these would be checked and lowered in an assembled condition. d) STIFFNERS These would be assembled and welded in twos. e) DOME WALLS

Each dome wall, both upper and lower is in two parts. These would be

assembled together before erection.

f) DOME SHIFTING STRUCTURE The central portion of the structure shall be assembled outside. g) CLEANING OF COMPONENTS The cleaning of components shall be done either by sand blasting using

low-pressure air (2.5 kg) or by alkali and hot water.







19

(VI) ERECTION This would be carried out as per the normal erection procedure given in

next chapter taking due care of all the normal / quality checks.

(V) TUBING The tubing of the condenser shall be carried out from the end of the

condenser. The opening in “A” row in front of the condenser is not to

be closed till tubing is complete. Tubes shall be transported on a long bed

trailer so that the overhang is not more than 1.5mm either side. In case a

small crane and space is available the tube boxes shall be unloaded near

“A” row columns. However, in normal cases the boxes shall be unloaded

inside the TG hall by EOT crane and shifted to position manually.

(VII) WATER BOX HANDLING DEVICE

This would be erected when the welding of internals is in the progress. In

case this is not available it would be better to have suitable openings on

TG Floor and oil canal from where the slings can be inserted to handle

the water boxes when they are opened for tube inspection.

(VIII) HYDRAULIC TEST - Steam space This would be tested by filling the water in the steam spaces to the

required level and the fluorescent powder shall be mixed with it. It would

be inspected by UV Light.

-Water space







20

This would be tested along with the RE joints and the butterfly valves.

This would ensure tightness of the RE joints flanges along with the

condenser. Moreover the time for fixing blanks can be saved.







21

ERECTION PROCEDURE







22

A. BOTTOM PLATE

I. PREPARATORY WORK

1. Check the foundation for dimensional accuracy in accordance with

the plate foundation drawings.

2. Set the support plates in mortar and align with the positions in

which the spring elements will be mounted.

II. ASSEMBLY SEQUENCE

1. Tack the base plates to the spring elements.

2. Lower hot well below and place it on the ground.

3. Lower the sections making up the bottom plate onto the support

plates of the condenser foundation.

4. Assemble and align the sections which have been lowered onto

the foundation.

5. Weld bottom plate as per sequence.

6. Lift hot well and weld with bottom plate. Align the bottom plate

to the turbine axis in zero elevation.







23

7. Raise bottom plate in axial direction and into zero elevation,

taking care that when condenser is finally tilted, its centerline

would match with turbine axis.

8. When the bottom plate is at zero elevation, shim plates under all

spring elements.

9. In order to avoid displacement of the bottom plate during

assembly of the water boxes and condenser shell internals, the

support bolts of all the spring elements must be in their

uppermost positions before the work is commenced.

10. Detach the tack welded base plates from the spring elements

and eliminate the weld spots.

PREASSEMBLY

1. Preassemble tube plates (L & R) and check for any distoration

of main tube plate.

2. Any deviation in alignment of holes should be similar in both

front and rear assemblies. In case of variation the matter

should be referred to the BHEL /HWR.

3. Assemble the water box covers with the water chambers

without gasket and check whether:

a) All bolts are fitting and

b) Any clearance in the parting plane, rectify if necessary.







24

4. In case suitable slings for lifting the complete assembly are

available then welding of the two halves should be done. In

case of any doubt, the assemblies can be lowered in parts.

B. CONDENSER SHELL

General preparatory work

1. Place the sidewall sections side by side, align and weld together

to from one complete sidewall. After welding together check

the sidewall for warpage and rectify, if necessary.

2. Welding of two or more pieces together outside the foundation

may be carried out.

3. Prepare the water boxes for installation by passing shackles and

wire cable through the lifting lugs.

Assembly Sequence

1. Hook up the prepared water box units to the crane and lower

through the foundation cavity, using hydraulic jacks as required

to secure the units against tilting.

2. As soon as the lowered water box unit is standing upright on the

bottom plate, match the center to the transverse axis.







25

3. Align the water box unit in the horizontal plane using water

level. Select two symmetric holes in the lowest outermost row of holes

on the right and left side. Insert guide pins in the selected holes, to be

used as oriented points for alignment.

4. Drop a plumb – bob to the bottom plate at each other edge

and move the water box unit into the vertical position. When the water

box unit has been aligned in the horizontal and vertical planes, tack weld

to the bottom plate.

5. Before the crane hook carrying the water box is lowered and

the load removed, the water box unit must be secured by means of

cables and stiffeners.

6. Repeat the assembly procedure described above for the second

water box unit of the condenser.

7. After tack welding, tack flat guides to the water box units and

bottom plate.

8. Do not weld the water box units to the bottom plate until the

sidewalls have been assembled, as otherwise weld warpage

may occur.

9. Hook up the sidewalls by means of shackles and cables passed

through the lifting lugs, move over the foundation cavity and

lowered onto the prepared location.







26

10. Align the side walls in lowered position and tack weld them at

several points to the water box units and to the bottom plate.

11. Remove the bracing cables, hosting gear, bracing lugs, etc.

from the sidewalls & dome walls & from the bottom plate.

12. Weld the complete shell.

CONDENSER SHELL INTERNALS

1. Preparation of the shell

Remove any accessories inside the shell & sweep the whole interior

clean. When preparatory work has been concluded, commence

installation of landing bars.

2. Installation of the landing bars

Mark the installation locations for the landing bars on the bottom plate

according to the drawings.

Locations are measured from the tubes, which will be and are marked on

the outer edges and the centerline of the bottom plate sides. Then move

the landing bars in to position, align and tack weld. Weld using the back

step method from both sides simultaneously.

Erect the vertical landing bars parallel to the landing bars on the bottom

plats. For this purpose, drop perpendiculars to the landing bars already

mounted on the bottom plate, mark the installation locations for the

vertical bars on sidewalls and tack weld the landing bars in position. Do







27

not permanently weld the vertical landings bars until the condenser has

been completely welded together namely after preassembly of the steam

dome. Remove weld residue from the weld zones using a chisel and wire

brush.

Preparing for installation of the tube support sections

1. Mount the flat iron supports for the air cooler shields and weld onto the

tube support plate sections with the aid of a template at the time of

attaching the landing bars onto the bottom plate. It is important to place







28

wooden beams under the tube support plate sections to prevent

deformation.

2. Installation of the tube support plate sections may then be taken up. Use

the lifting device to transport the tube support plate sections.

Installation of the tube support plate sections and internals.

1. Hook up each tube support plate sections upto crane. Lower into the

condenser shell and insert into the landing bars on the bottom plate and

sidewall, beginning at the front and the rear water boxes. During this

procedure, it is important that connection holes for the circulating water

pipe, countersunk by the manufacturer, face the tubing side.

2. Fix each tube support plate sections at least 4 / 6 points using

adjustable spacers.

3. Move sufficient tube support plate sections into the condenser shell and

fix them in position relative to each other by means of spacers to enable

the internals to be set down in the spaces provided in the tube support

plate sections. They consist of the following; steam baffle plates, part of

the air extraction line, as well as various bracing assemblies such as flat

irons and tubes necessary for later assembly of all the internals.







29

4. Insert stiffening rods inside the tube support plates.

5. Suitable tie rods should be used to hold the support plates against any

tilting.

6.Secure all tube support plate sections against tilting, since it is not

possible to commence alignment of the tube support plate sections

and assembly of the internals until after the steam dome including the

dome bracing has been preassembled and the condenser shell has

been welded together.







30

Alignment and welding of the condenser shell internals

1.Insert thin steel wires at four identical points in each tube plate of a

water box and feed the wires through the holes at the corresponding

points in the tube support plate sections. Hold the ends of the wires in

the centers of the tube plate holes using a special device and attach

the weights to keep the wire taut. Then align each tube support plate

sections in such a way that the tensioned steel wire passes through

the center points of the holes for the circulating water tube







31

2. Tack weld the tube support plate sections aligned with the center

point to the slot profiles on the bottom plate and sidewalls. After

tack welding, verify that the holes in the support plates lie in the

vertical and the horizontal planes. Enter the actual measurements on

the measurement data record provided.

The thin steel wire and alignment devices can now be removed, as

they are no longer for further assembly of the condenser shell

internals.

Move the internals temporarily housed in the spaces in the tube

support plate sections into their correct positions, align and tack

weld. Assembly the center joining plate and the bracing assemblies

such as flat irons and tubes.

3. Note: The stem baffles and bracing units must not be tacked

to the tube of the water boxes. This operation is not

performed until all the internals have been welded to one

another.

4. Align the various sections of the air extraction line, weld them

together to form one unit and tack weld to the tube support plates.

5. During alignment, ensure that air extraction openings are directed

towards the bottom plate and that therefore the connection holes for

the connecting piping systems are necessarily in the correct

positions. Pass out and fit the pipe work to the connecting piping







32

system through the connection holes. Set down the shields on the flat

iron supports, align and tack weld.

6. After assembly of all the steam space internals which, to allow for

welding warpage, may only be tack welded, commence welding of all

the condenser shell internals, the welding sequence being of up most

importance.

7 First weld the steam baffle plates, central joining plate, feed water

heating plate form, condensate drain sheets for the cooler tube nests,

bracing assemblies such as flat irons and tubes. Then weld the tube

support plates to the landing bar strips on the bottom plate.

8. Then weld the vertical landing bar strips to the sidewalls and tube

support plates. During this procedure, welders should as far as

possible work simultaneously. When the condenser shell internals

have been completely welded together, tack and weld steam baffle

plates, the bracing assemblies and the air extraction line and the

connecting piping system at the front and rear tube plates. When all

the welding work has been concluded, remove all weld residue from

the weld seams and weld zones in the entire condenser shell.

9. Note:

a) To prevent welding warpage, all welds must be performed

simultaneously from both sides using the back step method.

Vertical joints must be welded from top to bottom, i.e. from

the upper edge of the tube support plate to the bottom plate.

b) Welding with main tube plate should be done after all

internal welding has been completed.







33

Assembly of LPH in condenser

General:

Prior to the erection of LP heater and platform, the pipes for the

extraction system and throw device have to be erected/ placed in the

steam space.

Erection of the LP heater platform

Erection of the feed water heater platform start with mounting on the U-

profile steel support in the area of the central butt- strapping of the

tube-supporting sheet.

This involves firstly mating and bracing the support for LP heater

platform with the cut-to-size sheets and the ends of the associated U-

profiles. The I-profile girders for the feed water heater platform are

mounted on top these. The support brackets for the LP heater platform

support are then mounted on the dome walls on the water box side.

The elevations for the feed water heater platform support must

be assured.

Then the feed water heater platform and the dome bracing are installed,

aligned and welded as a unit.







34

Installation of the Feed water Heater through the Turbine

Foundation/Condenser Steam Dome Cavity

The LP heater held in the lifting tackle is inserted the turbine

foundation/condenser steam dome cavity and tilled to the required

angle. Insert the feed water heater through the turbine foundation into

the condenser by lowering crane hook and by gradually straightening out

the lifting bracket towards the horizontal plane.

Then move the feed water heater into the prescribed horizontal position

parallel to the feed water heater platform.

As soon as the horizontal assembly position is achieved, adjust the feed

water heater to the prescribed vertical elevation.

Mount support jacks on the I-profile girders supporting the feed water

heater platform and at the feet of the feed water heater to support the

feed water heater when it is set down from the lifting bracket.

Adjust all the support to the prescribed pressure and tack the load off

the lifting bracket.

Then take the actual dimension for the LP heater support, fabricate the

parts required and insert under the heater. Tack the load off the support

jacks as the permanent supports are inserted.







35

After completion of alignment of the feed water heater along the

longitudinal and transverse axis, the upper halves of the dome walls can

be installed, aligned and welded to the feed water heater as per the

drawing.

Note: The two upper halves of the dome wall on the water box

side are not to be installed and assembled until the installation of

the feed water heater through the turbine foundation/ condenser

cavity has been completed.

STEAM DOME AND BRACING

General

The assembly of steam dome is commenced when the condenser shell

has been adequately tack welded. Prepare the support points at the

upper edges of the condenser shell for assembly of the steam dome. Tilt

the condenser shell as per drawings. Ensure that centerlines are not

disturbed.

Preassembly of the steam dome walls

1. Preassemble the dome walls, divided into section for shipment,

according to the plant drawings. During this procedure the sections

making up a dome wall are assembled on the turbine floor with their







36

ribs facing upwards, aligned, adequately tack welded and then

welded to form one integral unit.

2. After completion of welding, clean the welding zone and examine the

dome wall unit for warpage. If necessary, realign the dome wall unit

to match the mounting dimension to the other component.

3. Prior to installing the dome wall unit, coat inaccessible weld locations

with anti-corrosive paint.

4. After this has been affected, measures out the dome wall units and

Mark the center points by punching.

Installation and Assembly of the dome walls

1. There is no specific sequence for the assembly of the dome walls.

Depending on on-site condition assembly may commence either with

the dome walls on the turbine and generator sides or those on the

water box sides. The dome wall units are hooked up using suitable

cable passed through their transport lungs, moved over the

foundation cavity and lowered into position on the upper edges of the

condenser shell.

2. The sloping edged metal fixtures mentioned above facilitate insertion

when assembling the dome wall on the turbine or generator side.







37

3. The dome wall remains suspended from the crane unit it has been

secured against tilting and slipping by suitable clamping.

4. Then the opposite dome wall is installed. When the two opposite dome

walls have been installed and secured, they are to be aligned with the

longitudinal or transverse axis. For this purpose, drop perpendiculars

from the steel wires on the longitudinal and transverse axes onto the

upper edge of the dome walls.

5. When the two opposite dome walls have been aligned, secure them by

tack welding to the steam shell.

5. Insert and install the adjacent dome walls as per drawing, as dome

walls are identical and must be moved into the correct position.

Assembly of Dome Bracing

1. Commence assembly of the dome bracing parallel to welding work

and after completion of the shell internals.

2. Lower the dome bracing, supplied in required lengths, into the steam

dome by crane, align in position and track weld.

3. When all the sections of bracing have been preassembled and track

welded, welding of the dome bracing to form one integral unit to be

carried out. However the connection with the LP cylinder should be

done only neck welding.







38

Assembly of Steam throw nozzles

After the dome walls have been tacked in position, the steam throw off

nozzles are lowered and rough aligned.

The final alignment is dome along with the LP Bypass down stream

piping.

WELD CONNECTION BETWEEN CONDENSER AND LOW PRESSURE

TURBINE

Welding the condenser to the low pressure turbine

1. After the condenser has been brought to operating weight by filling

water in the hot well or by the springs as indicated in condenser

erection drag and the spring supports have been adjusted to

compensate for welding contraction, prepare for welding the

condenser to the low pressure turbine.

2. Then fit the intermediate, corner and web plates as per gaps available

and prepare the weld edges.

3. Tack these parts to the condenser dome with welds with a tack length

of three times the plate thickness at intervals of 25 times the plate

thickness.

4. When all the aforementioned parts have been welded to the

condenser dome, tack weld to the low-pressure turbine.







39

5. Weld the joint using the back step method form tack to tack (see

diagram). When the base layer has been completed, make the

following filler weld layers, each in a single pass, and reversing

direction for each layer (see diagram).

6. After welding, clean the weld zone using suitable tools. When the

condenser has been completely welded to the low-pressure turbine.

Relieve the spring supports of the load applied to facilitate welding

and measure in relieved condition.







40

7. The spring supports must return to within +/- 1 mm of their settings.

If the deviations exceed this tolerance range, spacers must be used

to return the pretension of the spring supports to their original

settings.







41

8. Then immobilize the spring supports again.

INSTALLATION OF THE CONDENSER TUBING

General

The circulating water tubes, cut to length and provided with guide heads

delivered in crates to the site.

Erection of an assembly platform

Before erecting the assembly platform, remove the water box covers and

set down on wooden beams in a suitable location.

The assembly platform must be erected in such a way that it is safe to walk

on and presents no danger of falling off. In addition, it must be stable

enough to withstand the weight of the crates containing the circulating

water tubes.

Preparation of the holes for the circulating water tubes

The holes in the tube plates must be clean to the base metal. Clean all

holes using round steel brushes or reamers. Use of chemicals/ solvents is







42

not desirable. If the hinge assembly has been installed then one condenser

box can be opened at a time.

Installation of tubing

The tubings are inserted manually, Insert the tube from the bottom end

and pull through towards the top end until the same length of tubing

protrudes from the front and rear tube plates. Remove the guide heads

from the circulating water tubes. In case the insertion is difficult then the

tube should be taken out and the support plates rectified by reaming.

Tube expander

Use electronically controlled tube end expanders to roll the cw tubes into

tube plates. When the desired pressure is reached, the expander switches

to reverse speed.

The following points must be observed when expanding tube ends:

• The tube plate holes and the tube ends must be clean to the

bare metal and free from axial draglines.







43

• Before expanding in the tube ends, moisten the roller with at

least two drops of glycerin or vegetable oil. Moistening is

necessary to ensure that expander rollers rotate smoothly and

with minimum wear.

• The complete tube end expander unit consisting of the monitor

and the tube expander be kept together as one unit. If one part

is replaced the setting must be re-adjusted to give the correct

expansion as required for tight connection.

• The locking device on the roller head must be set to block the

rollers to a depth of 80% of main tube plate thickness before

reaching the steam compartment side of the tube plate. If the

tubes are expanded beyond the steam compartment side of the

tube plate, they will be damaged.

Finishing work on the tube plates and cw tubes

1. Remove any burrs at the tube inlet edges.

2. After expanding into the opposite tube plate, mill off the protruding

tube ends to the stipulated dimension and deburr the inner edges.







44

Preparing the water box covers and tube plates

Clean the joints of the water box covers and tube plates.

Note: When cementing the gasket, the joints must be free of

grease, clean and dry.

Assemble the rubber cord and spacer gaskets.

Assembly of the water box covers







45

The water box covers are attached to the lifting equipment using

appropriate cables, swiveled into the assembly position and moved in front

of the respective water box.

The hexagonal bolts and nuts necessary for the assembly of the water

boxes must be coated with a lubricant / graphite and subsequently

tightened.

The initial phase of this procedure is to tighten four bolts marked “ x “ in

figure. Afterwards all the bolts in the fig. are consecutively tightened

starting from the middle with x1, x2, x3, x4,x5, x6.







46

Caution: It is imperative that the bolts be tightened in two stages

HYDRAULIC TEST OF WATER BOXES

The condensers are subjected to a hydraulic pressure test on the cw side.

For this purpose, the cw inlet and outlet pipes must be blanked using

suitable hydro-test flanges and the manholes using the original covers. The







47

water box covers must be mounted ready for operation and a protective

coating must have been applied to the water boxes.

The hydro-test can also be done by closing the butterfly valves in the inlet

and outlet of condensers. This apart from also ensuring the tightness of

B.F. valves and expansion joints, reduce the time cycle as the temporary

test flanges need not be erected.

After the hydro test, drain the cw.

Hydro fill test on steam side

After the tubing has been completed, including the trimming of the tubes

the hydro fill test is to be conducted on the steam space.

1. Lock the spring supports in position.

2. Gradually fill the steam space with water. A water tube arrangement

is to be installed so that the level of water can be monitored.

3. During filling, constantly check the tubes for any leakage. In case

any leakage is observed, that particular tube should be further

expanded.







48

4. In case any tube is not getting sealed, it may be plugged.

Caution: This should be done as a last resort.

5. Fill the water upto last stage blade tip of LP Turbine and leave for 24

hours. Check thoroughly for any leakage.

6. Add a fluorescent dye (Sodium floursceine) 2-3 ppm (approx. 2 Kg)

to the filled water in the condenser. Stir the complete water and dye

with compressed air.

7. Leave the water for another 24/36 hours.

8. Finally inspect the tubes by ultra – violet light with the help of U-V

lamp.

9. When no fluorescence is observed it can be inferred that there is no

leakage.

10. During this test, other connected areas (falling under vacuum during

operation) can be inspected for any leakages.

11. Release the condenser springs, after all water has been drained from

both the steam space / cw side. The springs are finally set as per

drawings.

NOTE: Water should never be filled on both steam and CW side at

the same time.

SPECIAL PRECAUTIONS TO BE TAKEN DURING ERECTION:







49

1. The joining plates between the water chambers should be welded

and checked before lowering of condenser intervals.

2. The corners of the neck joint with LP turbine should be checked to

ensure completeness.

3. The welding of the stiffeners with the main tube plate should be

done only after welding of all support plates with the shell and

stiffness has been completed.

4. Welding sequence should be reversed for every layers of welding.

5. During preassembly of bottom plates / sidewalls & dome walls it is

advisable to put a packer below the joint so that during welding the

plates straighten out.

6. Not more than four welders should be deployed during the welding of

the internals. Adequate supervision should be exercised to ensure

proper welding sequence.

7. It is desirable that after 50% of the welding of internals has been

completed the alignment of the tube plates is rechecked. Subsequent

welding sequence should be decided based on the observation made.

8. During tubing in case the tube is not going freely the holes of the

tubes support plates may be reamed suitably.







50

LIST OF DRAWINGS







51

S Description Drawing No.

1. CONDENSER ASSLY (GA) 0 – 160 – 10 – 70043 C 80

2. CONDENSER GENERAL ASSLY.

(3 – SHEETS)

0 – 160 – 10 – 70043 ER

3. INSTALLATION OF LEVEL

INSTRUMENTS ON CONDENSER

2 – 160 – 00 – 70001 C 80

4. HANDLING ARRANGEMENT FOR

FRONT WATER BOX

0 – 160 – 00 – 70023 C 80

5. HANDLING ARRANGEMENT FOR

REAR WATER BOX

1 – 160 – 00 – 70060 C 80

6. BOTTOM PLATE 0 – 160 – 11 – 70010 ER

7. LOWER DOME WALL (TUR END) 0 – 160 – 12 – 70025 ER

8. LOWER DOME WALL (GEN. END) 0 – 160 – 13 – 70030 ER

9. SIDE WALL (TUR. END) 1 – 160 – 14 – 70005 ER

10. LOWER DOME WALL (FWB SIDE) 0 – 160 – 15 – 70032 ER

11. LOWER DOME WALL (RWB SIDE) 0 – 160 – 16 – 70036 ER

12. SIDE WALL (GEN. END) 1 – 160 – 17 – 70005 ER

13. DOME INTERNAL STIFFENING 0 – 160 – 27 – 70027 ER

14. SHELL INTERNAL DETAILS 0 – 160 – 28 – 70031 ER

15. AIR EXTRACTION PIPING 1 – 160 – 71 – 70027 ER

16. LP HEATER SUPPORT ARRGT. 0 – 160 – 38- 70001 ER

17. HOT WELL 0 – 160 – 28 – 70028 ER

18. CONDENSER SUPPORTS 1 – 160 – 71 – 70027 ER

condenser erection

Documents