Water Power and Dam Construction - Issue September 2009

Подождите немного. Документ загружается.

12 SEPTEMBER 2009 INTERNATIONAL WATER POWER & DAM CONSTRUCTION

INSIGHT

demand for green electricity and for the

balancing power that can be sourced from

our reservoirs. And this function will con-

tinue to grow alongside the rise of wind

and photov oltai c capacity with their fluc-

tuating output.”

Steinmann sees Nant as “a symbol of

Swiss hydr o ’s revival and a pioneer of col-

laboration between traditional power utili-

ties and the public transport sector.” SBB’s

jv with Alpiq is indeed the first such direct

UPPLY SECURITY

Nant de Dranc e will be Switzerland’s first

ever variable speed pump storage plant, cov-

ering growing demand for peak supplies on

the national grid and compensating for

irregular supplies of renewable energy.

Expansion of Switzerland’s pumped storage

sector through Nant and other projects will

support the feeding of new wind, solar and

other re n e w a b l e supplies into the national

and European network. Valais already hosts

Switzerland’s biggest wind parks at

Collonges and Martigny. “Security of supply

does not only mean produci ng enough,”

says Alpiq CEO Giovanni Leonardi. “It also

involves generating power at competitive

prices and from non-polluting sources.” The

head of Nant’s lead investor argues pumped

storage “is a vital element in supply securi-

ty. It helps iron out peaks in demand, it con-

tributes to network stability and it delivers

environmental benefits.”

Walter Steinmann, Director of the

Federal Department of Energy, also under-

lines this new role for Sw itzerland’s rich

hydro resources. “For decades it seemed

that the development of our hydro sector

had reached its limit s, with priority given

to other less capital-intensive forms of pro-

duction,” he arg ues . “Now we are seei ng

a renaissance of hydro power, thanks to the

investment by a major customer in Swiss

hydro capacity. Nant wil l improve supply

security for the railway operator’s network

and several private train companies that it

supplies. SBB already faces sharp load peaks,

especially in the morning when much of its

locomotive stock comes into service at the

same time. It projects a 65% jump in railway

demand for such peak energy over the next

20 years. New lines and improved services

threaten to outstrip current supply by 2015.

“In Switzerland seven of every 10 trains run

on hydro power, a figure unmatched any-

where in the world,” says SBB boss Andreas

Mayer. Powering expansion of Switzerland’s

train services is another indirect environ-

mental gain from Nant de Drance.

The project developers stress the minimal

environmental impact of this huge project.

Built 500m underground, the plant will

retain the existing dam walls at Emosson

(45m high) and Vieux Emosson (180m

high), dating from the ‘50s and ‘70s respec-

tively. Twenty p ercent of the mo re than

1.5Mm

solid spoil produced duri ng con-

struction work over the next eight years will

be reused for the preparation of concrete; the

remainder will be reintegrated locally using

modern landscaping techniques.

Winning local support and placating pow-

erful Swiss environmental lobbies were cru-

cial for Nant’s prompt go-ahead. But

pumped storage i s not without its critics –

Swiss energy foundation SES describes them

as ‘electricity washing plants’ for Europe’s

surplus coal and nuclear fired output. It also

claims many plants use more energy in

pumping than they produce. SES op poses

further expansion of Swiss pumped storage

– it estimates projects currently planned or

under construction will already increase

capacity from 1700 MW to 4600MW.

USTRIAN SITUATION

Neighbouring Austria is also reassessing its

hydro sector in response to rising power

demand and concerns over energy security.

Austria now imports 10% of its electricity

supplies, while hydro’s share of domestic

All photographs, except for below left, show

construction work on the Nant de Drance

pumped storage project in Switzerland

View of the dam and storage

lake at Verbund’s 900MW

Malta power project

www.stucky.ch

Over 80

ears of ex

erience in H

dro

ower & Dams

Dams

Strengthening of Les Toules arch dam,

Switzerland, construction, 2007-ongoing

Heightening of the Cambambe arch dam, Angola,

2008-ongoing

Hydro Power Scheme Rehabilitation

Cleuson-Dixence, rehabilitation of the steel lined pressure

shaft damaged in 2000, 4 km long, max. pressure 200 bars,

Switzerland, 2004-2009

Underground Works and

Structures

Deriner hydroelectric scheme,

underground power plant, 670 MW and anchoring

berms above the arch dam (H = 249 m),

Turkey, 1998-ongoing

Penstocks

Chandoline penstock, rehabilitation studies, 2002-2003, and

work supervision, 2004-2005, Switzerland

Risk Analysis and Management

Lake Sarez, Risk Mitigation Project related to Usoy

natural dam, the highest in the world,

Tajikistan, 2000-2006

Economic Analysis

Sambuco and Naret reservoirs, optimization of hydroelectric

schemes by pumped-storage facilities, Switzerland, 2004

14 SEPTEMBER 2009 INTERNATIONAL WATER POWER & DAM CONSTRUCTION

INSIGHT

IWP& DC

output has fallen from 56.7% in 1990 to

43.7% last year. Earlier this year the gov-

ernment confirmed it will implement the

‘Masterplan Wasserkraft’ (Hydro power

Strategy) published in 2008 by previous

Economics Minister Martin Bartenstein.

A report commissioned by the ministry last

year from Pöyry Energy claimed Austria

could boost hy dro output by 7TWh (or

12% of national production) to 2020 - a

move that would end import dependence.

The plan aims to increase renewable

output from 41.4BkWh to 55.7BkWh over

the next decade.

EUR2.3B (US $3.2B) will be invested to

2010, rising to EUR13.3B (US$18.5B)

over the following decade. Despite the

projec t title, only around half t he extra

suppli es will come from hydro. Almost

EUR5B (US$6.9B) will be spent directly

on new hydro power projects, with

EUR6B (US$8.3B) targeted on extension

and modernisation of the Austrian grid

and the remainder invested in other

renewable so urces.

Current Economics Minister Reinhold

Mitterlehner claims the strategy will create

95,000 new jobs in Austria. It will also bring

Vienna within reach of the EU’s ambitious

34% target for use of renewable supplies by

2020 – a near 50% increase on t he 2005

market share.

The 40 projects already i n the licensing

process are only half the total planned under

Masterplan Wasserkraft. Wolfgang

Anzengruber, newly-appointed chairman of

Austrian power supplier Verbund, argues

that hydro and other renewables could

secure a market share of over 45% if every

one of these proposals was realised by 2020.

For Anzengru ber, “it is unclear how

Austria can hope to meet its Kyoto targets

without massive hydro investments”, but he

rules out any dramatic resurgence of hydro

unless the government is ready to r eform

Austria’s plant licensing proc edures. He

urges Vienna to transfer licensing powers

from federal states to the national govern-

ment; give much greater weight to public

interest arguments in favour of major energy

and other infrastructure projects; and above

all to speed up the licensing process, which

typically takes over three years.

That call is echoed by Wolfgang Leitner,

President and CEO of Andritz. “We hope

Masterplan Wa sserkraft will involve an

acceleration of li censing procedures,” he

says. “Growing demand for power makes

the planned pump storage plants especially

vital. But that will also be a challenge to the

grid network. So we need to be forward-

thinking and not just f ocus on licensing

reforms for power plant construction.”

Bruno Wallnöfer, chairman of Tirolean

regional supplier Tiwag, also challenges gov-

ernment assu mptions about future hydro

growth. Tirol is the heartland of Austri an

hydro. Vienna claims an extr a 5300GWh

capacity can be tapped from its mountains

and lakes. “The Masterplan is unreal istic

and Tiwag won’t be pursuing it, ” says

Wallnöfer. “Anything above 1400GWh is

just fantasy.’ Again it comes down to plan-

ning proble ms. Tiwag and Verbund have

just invested over EUR2B (US$2.8B) in a

run-of-river plant on the Inn - ‘but licensing

delays mean we have absolutely no planning

or financial security for this project,” com-

plains Wallnöfer. He claims fi gures i n the

Masterplan are based purely on topography

and ignore the reality of in-built delay and

hostile lobbying.

UNDING ISSUES

Sceptics point out that initial spending pro-

jections under the plan have already been cut

in response to the current financial crisis and

concerns over budgetary debt. The source of

funding is also unclear. Mitterlehner insists

his ministry will not suppor t the hydro

sector’s expansion directly, but Verbund and

other regional Austrian suppliers are them-

selves partly in public ownership at nation-

al and federal state level. A new renewables

subsidy law, awaiting licensing clearance

from Brussels s ince las t September, is one

revenue source for small hydro projects.

“Funding is in place,” insists Anzengruber.

Verbund alone is investing EUR2.5B

(

US$3.5B) to add 1.3TWh hydro capacity.

“At present 26 hydro projects are in the

pipeline, at various stages from f easibility

studies t o renewal of machinery and the

building or modernisation of entire plants,”

he says. “But the delays are intolerable and

add on unnecessary extra costs.” Verbund is

xpanding pumped storage capacity with the

450MW Kops II plant in Vorarlberg and the

430MW Reisseck II in Carinthia, while the

480MW Limberg II pumped storage project

will more than double capacity at the exist-

ing Kaprun plant from 2011/12.

Plans for follow-on expansion at Kaprun

are threatened by Salzburg regional govern-

ment’s opposition to a new 380kV grid link-

ing the plant to its main market. “Limberg

III won’t be built without the 380kV

Salzburg line,” warns Anzengruber, while for

Wallnöfer Salzburg’s stance “is proof Austria

lacks any coherent national energy strategy.”

Appearing before a parliamen tary com-

mittee in his role as President of Austrian

power association VEO, Anzengruber urged

politicians “to hav e the co urage to imple-

ment these changes”. The industry is ready

to invest EUR1 5B (US$20.8B) to expand

production capacity – “that is an offer on

our part larger than all the anti-deflation

packages brought forward in Vienna,” he

says. “We just want to be allowed to get on

with it.”

Excavation work on the Nant de Drance project

One of Verbund’s storage lakes

S T R A T E G Y

M A N A G E M E N T

C O N S U L T I N G

E N G I N E E R I N G

C O N S T R U C T I O N

mwhglobal.com

312.831.3515

MWH, the wet infrastructure leader, builds, improves and retro ts

hydropower projects to provide clean, renewable energy. By

maximizing available sources of clean energy, we help clients

optimize the use of natural resources with sustainable techniques.

Our focus: conservation and control of the world’s irreplaceable

resource — water. Our goal: Building A Better World.

THE HYDROPOWER

LEADER

A R O U N D T H E W O R L D

16 SEPTEMBER 2009 INTERNATIONAL WATER POWER & DAM CONSTRUCTION

REHABILITATION

The company decided that, in order to meet the strict deadlines

set down by the power suppliers, it was necessary to divide and orga-

nize the anti-corrosion works into a number of different sections, as

shown in Table 1.

ECTION BY SECTION

After the upper water basin was emptied, phase 1 of the work could

begin on the 1385m long, 5.53m diameter penstock shaft, which lies

at a gradient of 54%. Once the climatization unit, scaffolding and

the movable work station had been installed, work began to remove

the old coating and apply the new Humidur coating on the vertical

armouring of the intake tower.

In order to meet tight deadlines, phase 2 of the work was carried

out parallel to phase 1. This involved renovation works on the inte-

rior surface of the upper water distribution pipeline, followed by the

renovation works in the pressure shaft.

The third phase of work involved treating the lower water distri-

bution pipeline and the riser shaft for the surge tank, amounting to

a total surface area of approximately 9600m

Phase 4 involved tr eatment of the cylindrical sluice gat e in the

intake tower. This involved lifting the gate and placing it on a plat-

form to allow access, once the necessary dewatering measures were

carried out. An opening of 1.2m x 1.2m was cut into the tower, with

CHLUCHSEEWERK AG operates and maintains five hydro

power stations in the Schwarzwald (Black Forest), Germany.

One of these projects is the 980MW Wehr pumped storage

scheme, which is located in southern Schwarzwald, above the

village of Wehr. The project has been in operation since 1976 and

features four Francis turbines installed in a hydro cavern.

The project’s water supply comes from the Hornberg Basin, on

top of Langec k Mountain near Hornberg, part of the town of

Herrischried. The water that passes through the turbines is collect-

ed in the Wehra basin in the Wehra Valley, near the town of Wehr,

below the hydro station.

After more than 30 years of operation, Schluchseewerk decided

that the anti-corr osion protection on the inside of the penstocks

needed to be renewed.

From the Hornberg ba sin, an armoured pressure sh aft run s in

front of the cavern into the upper water distribution pipeline, in

which it is divided over the different machine groups. The overall

length of the pressure shaft amounts to about 1385 m. The inner

diameter is 5.53m, reducing to 1.9m in the distri bution pipeli ne.

The pipelines of the pressure shaft lie underground and are only

accessible from entrances in the upper basin, over the cavern and

from the distribution pipeline.

The lower w ater distrib ution pipeline can be reached over the

cavern – the lower water basin could only be used in a limited way

as it remained filled.

ROJECT CONCEPT

In 2006, a project group was created consisting of representatives from

Schluchseewerk and Tiroler Wasserkraft AG (Tiwag). This group was

responsible for the project concept, creation of the tender documents,

evaluation of the offers and the decision to award contracts.

The decisive factor in this project was the selection of the coating

product to be used. A number of factors had to be considered includ-

ing: influence on the site installation, climatization, exploration, qual-

ity of the blast cleaning, application, controls, schedules, etc. After

evaluating several possible solutions, the project group decided that

Humidur would be the most appropriate product for this project.

The advantages of this product are essentially its thick layer appli-

cation, easy repair method, the possibility of applying the product

even at low substrate temperatures, experience in comparable pro-

jects, and lack of solvents and hazardous substances. Another impor-

tant aspect was the on-site assistance provided by the coating supplier.

EEPING TO SCHEDULE

Once the tender for the anti-corrosion work was issued, several inter-

national bidders submitted offers, with the cont ract ev entually

awarded to German company Arge Bauschutz-Bekor.

The solvent-free two-component epoxy resin system Humidur was recently put to use on a

renovation project at the Wehr pumped storage plant in Germany. A Zwanzinger, E. Rainer

and T. Huber detail the work involved in renovating the project’s anti corrosion protection

Renewing anti-corrosion

protection at Wehr

Table 1: Schedule of work

mpty the upper basin, pressure shaft

and upper water distribution pipeline 2 April 2008 - 10 April 2008

Empty the lower water tunnel and

lower water distribution pipeline 14 April 2008 to 18 April 2008

Anti-corrosion works in the

pressure shaft Mid July 2008 to 3 March 2009

Anti-corrosion works in the upper

water distribution pipeline May 2008 to July 2008

Anti-corrosion works in the lower

water distribution pipeline May 2008 to January 2009

Anti-corrosion works on the cylindrical

sluice-gate including constructional

mechanical repairs September 2008 to November 2008

Anti-corrosion works

Lindau – bypassing October 2008 to December 2008

Filling the lower water tunnel and

distribution pipeline January 2009

Filling the pressure shaft 17 March 2009 to 26 March 2009

Back into operation 16 March 2009 to 6 April 2009

REHABILITATION

WWW.WATERPOWERMAGAZINE.COM SEPTEMBER 2009 17

mechanical repairs carried out by the principal engineer, in consul-

tation with the contractor.

The fina l phase of th e work cons isted of renewing the interior

coating of the Lindau-bypass (about 1500m²).

For the treatment of several smaller parts in the hydro power sta-

tion, a blasting box (blasting shed) was erected and these works were

performed at the same time as the larger parts.

ITE REQUIREMENTS

In general, for all the works on the surfaces of Phase 1-5, the equip-

ment had to be asbestos and PAH safe and the works had to be exe-

cuted in accordance with the prevailing standards. Based on the data

provided by the suppliers of the old anti-corrosion product, together

with analysis of the newly produced coating material, the hazardous

substances in the applied old coating were determined. This is turn led

to the development of the anti-corrosion works plan, in accordance

with TRGS 519 and 551. As a result of earlier experiences and in con-

sultation with the authorities, it was decided to remove the old coat-

ing by means of conventional dry blast cleaning.

Since there was a possibility that percolation water or mountain

water could come down from the artificial lake, dewatering had to

be installed, in consultation with Schluchseewerk AG.

To make th e int erior su rface of the pressure shaft (Phase 1)

accessible for treatment, a movab le working platform was nece s-

sary. The h o i s t needed to move such a platform could be attached

to securing points already provided for in the upper water basin.

Climatization

Treatment of all the surfaces had to be done in an air-conditioned

atmosphere – the surfaces to be treated needed to be permanently

dry, even when the weather conditions outside were unfavourable.

Moreover, in accordance with the principal engineer’s specifications,

the surface tem perature of the s teel armouring in the parts to be

treated had to be maintained to at least 5°C above their dew point.

The relative humidity of 40% was not to be excee ded until after

completion of the first coating layer application.

For technical reasons, it was necessary for the conditioned air to

be warmed by means of a heating system equipped with a switch-

box and adequate generator sets.

The climatization and ventilation had to be installed in such a way

to avoid pulverization. Consequently, it was necessary to clean all the

exhaust air through dust filters. In addition, during removal of the old

coating layer, asbestos and PAH filter installations also had to be used.

The contract o r was responsible for contro l of the as b e st o s and

PAH content of the exhausted air, and at all times had to prove that

the values remained within the legal limits. If the contractor failed

to take these measures against pulverization, the works would have

been stopped immediately.

Rust removal by blast cleaning

Blast cleanin g to remove rust could only start once the air condi-

tioning had been installed and dewatering was functioning.

Schluchseewerk prescribed a cleaning up to Sa 3 in accordance with

DIN EN ISO 12 944 part 4 and required a purity degree of at least

m2/g2 to conform with technical report DIN Nr. 28 (also refer to

Left, from top to bottom – Application of the first layer of Humidur on the

vertical armouring of the intake tower

The finished coating on the lo wer water p ressure pipeline , with the extra

layer on the bottom p late and th e sickle-shaped pa rt (upper end of the

distribution pipeline)

The finished coating of the upper water distribution pipeline with an extra

layer on the bottom plate and the sickle-shaped part (most vulnerable parts)

Finished coating on the cylindrical sluice-gate

Application of the second layer of Humidur in the Lindau-bypass

18 SEPTEMBER 2009 INTERNATIONAL WATER POWER & DAM CONSTRUCTION

DIN EN ISO 8502, Part 3). In order to assure a maximum adhesion

of the coating system on the steel surface, an ave rage roughn ess

degree Rz of at least 60 µm had to be obtained. Only new un-used

blast cleaning material could be used during the final blast cleaning

phase.

The used blast cleaning material had to be transported, dust free,

through an exhaust installation and over a conveyor belt, and

deposited in suit able bags in accordance with in structions of the

principal engineer and the authorities. The bags then had to be made

ready for transport and stored in the dedicated places.

The surface was firstly blast cleaned, against the direction of the

air flow, to remove the old coating (black surface). After cleaning

and independent measurements by an acknowledged institute, the

urface to be treated was released (white surface) and blast cleaned

for a second time, with new blast cleaning material, up to a purity

degree of Sa3 (Rz > 60 µm) and de-dusted.

The new coating

Following the blast cleaning and sample testing of the welding joints,

the surface was ready for the new coating.

In accordance with the specifications of the tender, the solvent-

free 2-component epoxy coating Humidur ME was to be applied in

two layers (one light grey, the other light blue) with a dry film thick-

ness of at least 600 µm (total dry film thickness of the two layers).

In order to ensure a longer lifetime of the anti-corrosion system –

taking into account the present erosion in the areas of the bottom

plate and the sickle-shaped part – an extra layer of Humidur in sand

yellow was applied on the bottom plate and on the sickle-shaped

part where erosion was discovered. The total dry film thickn ess

(DFT) in the areas where this extra layer was applied had to be at

least 1000 µm. The coating was app lied usi ng crosswise airless

spraying.

After application of the first layer (directly on the steel – no primer),

the coating was tested for open pores by means of a spark test and

the coating thickness was measured. Weak spots or open pores were

REHABILITATION

Table 2: Surface area of the works

Work phases Surface in m²

Phase 1 Pressure shaft 24.000

hase 2: Upper water distribution pipeline together with

the level surface of the pressure shaft 5.400

hase 3: lower water distribution pipeline with surge tank 9.600

Phase 4: Cylindrical sluice-gate 400

hase 5: Lindau-bypassing 1.500

otal surface 40.900

The finished coating in the lower water distribution pipeline, with the

extra layer on the bottom plate and the sickle-shaped part

Part of the housing and the lock system for the black area as well as the

measuring equipment to monitor the underpressure

Control of the sandblast cleaning in the pressure shaft, final control of the

cleaning (adhesive tape test) before release for coating application

The picture shows a part of the climatization installation in the upper

basin, for the climatization of the pressure shaft

Inspection of the cleaned steel surface in the lower water distribution

pipeline. The amount of dust was tested with adhesive tape, to see whether

the purity degree m2/g2 (DIN EN ISO 8502, part 3) has been reached

Application of the second layer (blue) in the pressure shaft. After

application of the first coating layer (grey), the welding joints were

coated by brush with yellow coating

WWW.WATERPOWERMAGAZINE.COM SEPTEMBER 2009 19

REHABILITATION

brushed once more and the welding joints were treated with a brush.

After quality assurance personnel approved the treated surface, a

second layer of Humidur was applied, with the third yellow layer

sprayed on the bottom plate and on the sickle-shaped part.

Since no maximum intermediate curing times are needed for this

coating, and the fact that the waiting time before the application of

the next layer only depends on the mechanical load-bearing capac-

ity (whether the work station can be moved over the coating), a more

flexible way of working is possible when compared with tradition-

al coating systems.

The finished average layer thickness amounted to 1200 µm, with

1400 µm applied on the bottom plate and the sickle-shaped part.

ONCLUSION

To ensure the Wehr hydro plant was only out of service for a short

time, the schedule for this proje ct was very tight. The use of the

Humidur coating system helped ensure the execution time for this

project remained short.

Thanks to the experienced quality assurance team and extensive

assistance provided by the coating supplier, the project was com-

pl eted successfully and to a high quality. New dim ensions were

reache d on this project wi th regards to the built-in coating

quality.

Mag. Alois Zwanzinger, Corro Tec Korrosionsschutz

Vertriebsges.m.b.H., Grinzinger Strasse 72/E35, 1190,

Vienna, Austria. Email: alois.zwanzinger@aon.at,

www.corrotec.at

Ing. Edwin Rainer, TIWAG-Tiroler Wasserkraft AG

Eduard-Wallnöfer-Platz 2, 6010 Innsbruck, Austria.

Email: edwin.rainer@tiwag.at, www.tiwag.at

DI Thomas Huber, Schluchseewerk AG

Säckinger Strasse 67, 79725 Laufenburg (Baden), Germany

Email: huber.thomas@schluchseewerk.de

www.schluchseewerk.de

Ion permeability of Humidur ME

Measuring ion per meability on a coating, according to engineer Peter Heinze,

ives an objective opinion about the dif fusion tig htness of that coating

Why is diffusion tightness such a critical item?

n order to prevent corrosion damage on structural steel, a protective coating

an be applied. This coating is expected to maintain a barrier function

between steel and water and must be as watertight as possible.

alts and corrosion residues on the steel surface attract the water, even

hrough a coating. Therefore, the coating applied needs to be diffusion tight.

The diffusion process itself can be influenced by different factors, eg. salt

residues, dust or dirt on the substrate, solvents in the coating, water quality,

tc. In order to determine whether one coating performs better than the other,

specific method of measuring and comparing these coatings is addressed.

Applied measuring methods for diffusion tightness

One accepted method is determining the water vapour transmission rate by

he dish method or the cup method (NORM ISO 2528). A small amount of

water is kept air-tight in a metal cup, closed by the coating film to be studied.

The weight of the total case will be determined at the beginning of the test as

ell as at the end, while keeping the film thickness in mind, and both results

are compared to determine the vapor loss or water loss through the coating

film. The cup will suffer different conditions due to changes in temperature

and humidity. These results are put in g/m² per day.

Another test for measuring diffusion tightness is the !-T Test. This test

etermines the diffusion rate of water through the coating, based on several

parameters eg. the layer thickness of the coating, application of the coating,

temperature and quality of the coating. The result of this test is put in days

until bubbles appear on the coating surface.

A new measuring method is put into practice…

For the first time during a project in the hydro power sector, quality assurance

measures onsite included a new test method for the diffusion tightness. For

renovation of the corrosion protection in the Wehr project’s pipelines,

substrate-free coating films of Humidur ME were produced. In parallel to the

application of the Humidur coatings, one-layer and two-layer coating films

were applied to a non-adhering foil.

After curing, the films were sent to the laboratory of Mr. DI Heinze

(Germany), in order to investigate the ion per meability.

The ion permeability test is a new method to measure quickly, with

evidential results, the diffusion tightness and consequently the effectiveness

of a coating as a corrosion protection (for further information, see

www.ionperm.de). The smaller the ion permeability (IP) and the lower the

value of the constant CI, the better the corrosion protective effect of the

coating. The constant CI is a reference value that does not depend on the

layer thickness.

The diagram below shows the test results of:

• The blue one-layer coating Humidur ME on the pipeline in Wehr.

•

The two-layer coating Humidur ME, one blue and one yellow, compare d to

several conventional coating systems. T he one-layer as well as the two-

layer Humidur film reveal an essenti ally lower permeability for ions and

therefore a higher diffusion tightness. Consequentl y, the corrosion

protection by Humidur compared to the other coating systems is expected

to be considerably better.

Description of the tested coating materials:

•

Sample 1 - Epoxy - coaltar combination, solvent free, two layers

• Sample 2 - Epoxy coating material, solvent free, two layers

• Sample 3 - Epoxy - coaltar combination, solvent free, water emulsifying,

four layers

• Sample 4 - Epoxy coating material, containing solvent, four layers

• Sample 5 - Epoxy - coaltar combination, low solvent content, four layers

• UWW 1 lb - Humidur ME, one layer

• UWW 2lby - Humidur ME, two layers

These results also confirm the excellent anti-corrosion proper ties of Humidur.

For the Wehr project in par ticular, the anti-corrosion protection is expected to

have a very long life.

Further information about this project and references in the hydro power

sector can be found on www.acotec.be or www.corrotec.at.

With consent of engineer Peter Heinze, PH Ionenpermeabilität, Germany and

Schluchseewerk AG, owner of the Wehr hydro power station, Germany.

IWP& DC

References

Schluchseewerk : several documents and sketches, Laufenburg, Deutschland

Ing. Edwin Rainer : Quality assurance for anti-corrosion protection works,

especially in pressure pipelines, illustrated by practical examples. Congress

documents : 11th international seminar on hydropower installations : The

importance of hydropower in changed market conditions, TU Vienna, 15 to

17 November 2000, published by DI Peter Angerer, o.Univ.Prof. DI Dr. techn.

Dr. hc. Heinz-Bernd Matthias, page 141 and following.

Sample 1

0,07100

Sample 2

0,05000

Sample 3

0,14000

Sample 4

0,14000

Sample 5

0,16000

Sample 6

0,00095

Sample 7

0,00066

0,18000

0,16000

0,14000

0,12000

,10000

0,08000

0,06000

0,04000

0,02000

KI pMol/h x cm

Ion permeability of different corrosion materials

CI pMol/h x cm

Turbines & Generators

VLH (Very Low Head) Turbines

Balance of Plant

Electromechanical Equipments

Switchgears

High Voltage Substation

Control Protection Monitoring & SCADA Systems

Operation and Maintenance

S.T.E. ENERGY S.p.A. | ISO 9001 CERTIFIED

Via Sorio, 120 - 35141 - PADOVA (Italy)

Tel. +39.049.2963900 - Fax +39.049.2963901

(PDLO VWH#VWHHQHUJ\FRP  :HE ZZZVWHHQHUJ\FRP

“Water to Wire” General Contractor

Turnkey Projects

Rehabilitations

Worldwide reference in: