Issue 01 / 2017

A SPECIAL BIRTHDAY

Cast Iron and EnamelTwo natural materials combined

Page 10

60 Years Düker EnamelEvery success story starts with a brillant idea ...

Page 4

New ProductDüker non-slam check valve type 8015

Page 14

WASSERSPIEGELNEWS FROM THE WORLD OF FITTINGS AND VALVES – MADE BY DÜKER

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Welcome to the new edition of our clients' magazine "Wasserspiegel".

The previous edition highlighted almost exclusively new products and fair trade novelties. In 2017, however, we are taking a good look back into time – with a very good reason! In 2017 we cele-brate 60 years of enamelled Düker gate valves!

Since 1957 Düker has been the pioneer of enamelling for wa-ter supply products. The surface protection enamel has accom-panied Düker since the 1920s, when the Karlstadt subsidiary started enamelling bathtubs. However, the powder enamel used for baths would not have been suitable for valves. The breakthrough came with the introduction of wet enamel.

In spite of its long history, the compound material cast iron and enamel can most certainly not be considered a "technology of the last century". On the contrary, cast iron and enamel face all modern requirements competently and without problems. The performance of enamelling is also recognised internationally, as proven by the new international standard EN ISO 11177.

The Düker backflow preventers are also celebrating a milestone anniversary – they have been part of the range for 50 years now, and are now having a brilliant new entry with the new Düker non-slam check valve type 8015. Optimal flow conditions

and therefore minimised pressure loss are the characteristics of the Düker non-slam check valve. Of course including the proven inside and outside Düker etec enamelling!

Most of our readers will be particularly interested in the prac-tice of water supply projects and pipeline construction. There-fore we are glad to present you a successful application exam-ple of another Düker product, a butterfly valve with ventilation devices.

The last double page is again reserved for the presentation of the Düker team. Your contacts are looking forward to hearing from you!

Until then we wish you a good time when reading this "historical" magazine. By the way, we would be very pleased to hear your comments or remarks!

DEAR READERS,

EDITORIAL

Martin Simons Gerald WernerManaging Director Export Management

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PRODUCT INNOVATIONS

Düker started the first chapter of the success story of enam-elled valves for water supply with a resilient-seated gate valve with inside enamelling. Until today, the resilient-seat-ed gate valve, which by now has inside and outside enamel-ling, is the company's visiting card – with worldwide appli-cation.

Düker – a company with a long tradition1469 – foundation of a smeltery – later on foundry – machine factory – 1897 some first items for water supply – 1947 enamelling shopfor highly acid-resistant contract enamelling – 1952 start of valve developments.

2004: Development of a new enamel technology for inside and outside enamelling.With the brand etec enamel Düker introduces a new standard in valve enamel technology. A highly resistant enamel against corrosion loads of the soil class III as per the definition of the DVGW worksheet GW 9. Tested by the German Federal Authorities for Material Testing (BAM) in Berlin. With this complete enamelling, all material-related advantages of enamel are applied within a closed system.

In the years of the economic boom, environmental protection and sustainability were practically unknown terms. Today, 60 years lat-er, environmental considerations are more than ever in the centre of awareness. Enamel on the basis of a technical glass scores high in this respect!

See the article on page 10 and 11 "Enamel is worth its weight in gold".

Based on 60 years of experience, it is uncontested today that the typi-cally blue Düker enamel is far superior to all other known coatings. This is also proven by the fact that, after quite a long pause for reflection, today almost all notable valve manufacturers have integrated enam-elled valves in their range of products. Today still, enamel for valves is a superlative innovation.

60 years Düker enamel. 60 years "Made in Germany". A special birthday. For 60 years we have been the enamel expert at your side! In the past, in the present and in the future.

1957 – The great success: The first resilient-seated gate valve with inside enamelling was produced. Enamel was a revolution of valve technology. Enamel was only known from the cooking pot at home and was known to easily chip off. There-fore this solution was ridiculed by many at first. But practice tests overcame reservations, and the newly developed surface technology rapidly won the confidence of the water supply sector.

The belief that enamel chips off has always been a prejudice. With newly developed process technology, it was possible to produce thin enamel layers, which are flexible and therefore very resistant to me-chanical stress and impacts.

Enamel is hard as glass, smooth as glass, hygienic and diffusion-safe. With these characteristics, the new surface protection fulfilled the el-evated desires of the water supply industry for durable functionality, long lifespan and economy.

Everything went very fast after that. The product range for water supply was expanded speedily with underground hydrants, medi-um-height hydrants, tapping valves, backflow preventers, double-ec-centric butterfly valves and many more items.

60 YEARS OF INNOVATIVE ENAMEL

TECHNOLOGY EVERY SUCCESS STORY

STARTS WITH A BRILLIANT IDEA …..

Back into timeIn the pipeline construction of the time, metal-seated gate valves were still in use. But the water supply companies complained about considerable malfunction rates with leaky stem seats, deposits in the valve bag and erosive corrosion on the inside. Valves with extremely high operation forces and valves which no longer closed reliably had to be exchanged again and again. The water supply industry was des-perately looking for economical alternatives.

In co-operation with the responsible staff of municipal utility and wa-ter supply companies, Düker thought about alternatives in order to get rid of the faults in the system.

As early as in 1954, the first glandless gate valve with bellows mem-brane were manufactured. A highlight was the new interior stem in O-ring bearing. A grey-coloured plastic coating served as corrosion protection – an absolute novelty at the time. Yet this surface protec-tion was not the optimum. The application of the plastic powder was difficult and time-consuming. Furthermore, the adherence to the basic material was not guaranteed durably and completely, due to the diffu-sion characteristics of the organic plastic coating.

An alternative was required. The solution was ENAMEL!

2006Type 4004 – new enamel

technology Düker etec enamel

as an all-around protection for

use in soil class III – obturator

with vulcanised sliding shoes on

the sides, bonnet constructed as

bayonet without machining

1952 1960 1970 1980 1990 2000 2010 2017

t

On the basis of the proven gate valve and enamel

technology, the Düker products are permanently

developed further. The all around Düker etec enamel

is used for butterfly valves, service connection

and tapping valves, hydrants, backflow preventers,

and in the future even for control valves. On pillar

hydrants, enamels in colours combine protection

and optical aspects perfectly.

After 60 years, the Düker enamel history

is not over yet and will not be for a long time!

Düker today

1957bellows membrane gate valve with

interior steam. Bearing in O-rings.

Corrosion protection enamel.

1954bellows membrane gate valve

with interior stem. Bearing in

O-rings. Corrosion protection

plastic powder. 1962Type 163 – one-part obturator,

rubberised on all sides, stem

with two O-rings and a gliding

ring, maintenance-free bearing

1972Type 4000 – general

conversion from grey cast iron

to ductile cast iron – further

development of enamel tech-

nology, conversion from black

enamel to blue enamel

1977Type 4000 – with TYTON®

plug-in sockets

1982Type 4001 – weight-optimised

– new obturator geometry

1986Type 4001 – with PVC socket

1987Type 3000 – with steel

welding ends

1992Type 4001 – with NOVO plug-in

socket (double chamber)

1989

1969Type 163 – in short face-to-

face length, made of ductile

cast iron

Type 4001 – with PE-HD

welding ends

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5,400 km of potable water pipe networkHamburg Wasser, the Hamburg local water supply company, operates a potable water pipeline network of a length of approx. 5,400 kilo-metres. Approx. 900 kilometres of the pipelines are of a dimension larger than DN 300. The number of shut-off valves is correspondingly high. There are regular requirements for valve exchange.

In the course of such exchange works, it is standard practice nowa-days to equip shut-off valves from DN 400 up with a closable bypass. Such a bypass allows to fill and to empty pipelines without danger of water hammer. Another aspect is the purging of air during the filling procedure.

In a market survey covering double-eccentric butterfly valves, the ex-perts of the Net Section West found the butterfly valves with long face-to-face length by Düker. When replacing an old gate valve, it is often possible to do a simple exchange.

During a visit to the manufacturing site in Laufach, the discussion turned to a butterfly valve DN 600 which was supposed to be ex-changed shortly. As the valve is positioned at one of the highest points of the pipe network, a ventilation device was to be installed during the construction measure.

Individual special solution Finally the following special solution was found: Butterfly valve DN 600, PN 16, long face-to-face length R15 with upper bloc flanges DN 80 for the installation of a ventilation before and after the sealing seat, in underground installation, combined with two underground hydrants.

Author:Gerrit Kessler, Foreman Subcontractors, Net Section WestHamburg Wasser

PROJECTS

Installed butterfly valvewith two underground hydrants

PRACTICAL APPLICATION:

BUTTERFLY VALVE LONG FACE-TO-FACE

LENGTH WITH VENTILATION

HAMBURG WASSER WATER SUPPLY COMPANYDRINKING WATER FOR TWO MILLION PEOPLE

THIS COMPACT SYSTEM ENSURES

the filling and emptying of the pipeline without danger of water hammer through the hydrants

a manual aeration and ventilation through hydrant standpipes

aeration and ventilation with automatic hydrant ventilation devices.

OTHER ADVANTAGES:

compared to the usual design with separate fittings, the trench was significantly smaller.

the material cost was lower.

the clients and the area around the construction site suffered relatively little disturbance.

the cost of the measure was reduced by more than 30%.

Foreground: butterfly valve with two bloc flanges on top

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Water is a unique and mysterious elementWater has sculpted the earth and started evolution. Unlike any other element, water has influenced our culture and civilisation.

Not a drop is lostWater is not used up and lost. The water quantity on earth neither increases nor decreases. Water moves in nature in an eternal cycle. Water evaporates, rises into the atmosphere, comes back down to earth as precipitation. A part of it is taken in by earth and plants. Another part returns to the sea through streams and rivers. The water cycle starts again.

Water supply companies join this cycle. They extract potable water from ground, surface or source water, treat it and pass it on to the users. After its use the water flows into the purification plant and back into the rivers. The cycle starts again.

The water cycle is a part of the global system. It influences the earth climate, ensures water supply, helps in our steady provision with oxy-gen and permanently builds up a protecting ozone layer.

An important and responsible taskKeeping up this system for following generations is an important task. Düker has been facing it for decades. With innovative system solutions we ensure that the valuable resource water and our envi-ronment are protected. With the materials cast iron and enamel we join the cycle.

Enamelling is a high-quality economic, ecologic and valuable surface protection.

NOT A DROP IS LOST

DÜKER OFFERS INNOVATIVE SYSTEM SOLUTIONS FOR THE PRESERVATION AND PROTECTION

OF THE VALUABLE RESOURCE WATER AND THE ENVIRONMENT.

SUSTAINABILITY

Precipitation

Purification

Water Supply

Ground Water

Use

Transport

EnamelledValves andFittings

Recycler

Düker

Evaporation

WATER – IS LIFEThe beginning of being and decay. An eternal cycle.

WATER – A GIFT OF NATUREIt determines our existence like no other element. Without water no organic life is possible.

WATER – A GIFTIt has been given to us so we use and preserve it, and pass it on undamaged to generations coming after us.

WATER – OUR MOST VALUABLE GOODIt is our most important food. It cannot be replaced by ANYTHING ELSE.

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Enamel, on the basis of a technical glass, and cast iron melt togeth-er to be linked together inseparably

Quality products "Made by Düker" Düker valves and fittings made of ductile cast iron, all around with the unmistakable blue etec enamel, are manufactured in Germany at the Düker works in Laufach and Karlstadt. The Düker brand stands for innovation, quality, technology and sustainability. The responsi-ble use of modern technologies, energy-saving production processes, customer service, consideration and respect of people and environ-ment are essential components of our company's strategy.

Responsible use of resourcesThe liquid iron is made almost exclusively from recycled used metal. Any waste material such as return scrap from the casting plants or swarf and chips from machining are added to the internal material cycle and are molten down again. This saves energy and protects valuable resources. But also the slag resulting from the iron produc-tion or any sand from the casting that cannot be reused internally are processed in cement mortar works and in road construction – an ecologically reasonable use.

Safety and CleanlinessMetal scrap that comes into the factory goes through the Düker Gei-ger counter gate. We consider this additional control for possible radioactive components as a necessary measure. It serves for the

protection of our employees and our products. Furthermore it also protects the potable water, which will later flow through the pipe-lines and valves, and therefore the people who will get in touch with it later on.

At the end of the production process, each valve undergoes a pres-sure and operation test. This test is done exclusively with potable water, which guarantees the highest degree of hygiene while consid-ering economical aspects.

Enamel, a special glass on an inorganic basisThe raw materials for enamel are quartz, feldspar, borax, soda, pot-ash, and metal oxides. All these materials are available in nature in sufficient quantities, and for a long time to come. The extraction is for the most part in Germany. This avoids long transports. Another plus for environment and climate.

Pureness and hygieneIn the complete production chain of enamel, no organic materials are used. Water is the only dispersant and cleaning agent. Enamelled surfaces with their purely inorganic structure cannot serve as a nutri-ent ground to microorganisms. The smooth surface makes an infes-tation difficult. The so-called "invisible dirt" does not have a chance to settle on enamelling. Absolute hygiene is therefore guaranteed durably and on a long term.

Enamel is a material and a resourceFrom the ecological point of view, enamelled cast iron products are better by nature. They can be recycled without effort. This reduces waste quantities and protects resources. The cycle from the material to a new product can be closed successfully.

Cast iron and enamel - two natural materials allied for pure enjoy-ment of water and for high-quality Düker products

SUSTAINABILITY

"ENAMEL IS WORTH ITS

WEIGHT IN GOLD"THE ART OF CREATING SUSTAINABLE PRODUCTS

ENERGY-EFFICIENT, ENVIRONMENTALLY FRIENDLY AND SUSTAINABLE

ENAMEL – THE PERFECT "PACKING"

Optimal protectionEnamelling combines the material characteristics of cast iron and glass in the ideal way. During the burning process at approx. 780 °C, a new, tightly entwined com-pound material comes to life. Corrosion creep is impos-sible! Enamel is a substance-to-substance bond which guarantees permanent corrosion protection. An added value for durability, economy, safety and sustainability.

Protection smooth as glassRegarding sediments from the medium, the enamel sur-face behaves in a similar way as the lotus leaf in nature. Incrustation has no chance to accumulate. An added val-ue for durable functionality.

Inert – chemically inactiveAn extremely low diffusion coefficient is a typical charac-teristic of glass. Enamel does not emit any components into the medium and does not absorb any aromas or other substances from the medium or the environment. A safe separation – inside and outside! As enamel con-sists of inorganic materials, it is furthermore odourless and tasteless.

In short: enamelled valves and fittings are the "best pack-ing" for our drinking water. Just like a bank safe, they protect the valuable contents permanently and guaran-tee a pure and untainted taste.

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DÜKER STORIES

Bad Homburg is one of the most important business locations in the area around Frankfurt/Main. Numerous national and international companies and some federal agencies have their seat there. The water supply of the 52,000 inhabitants is in the hands of the public utility com-pany Stadtwerke. Every year they supply approximately 3.3 million of cubic meters. Ten plants extract water in order to provide for the town's daily water requirements.

One of these plants is the Elisabethenstollen duct in the municipal woods of Bad Homburg. This duct alone supplies 30% of the daily po-table water quantity. Between 1955 and 1962, a horizontal duct of a length of almost two kilometres was dug through the bedrock in order to reach the most productive places. At the end of the duct, there are

four reservoir chambers, separated from each other by massive steel doors. Pipes and fittings are installed in order to regulate the water abstraction from the various reservoir areas.

After decades of use under extreme duct conditions, the pipe system was slowly decaying. In order to ensure the water supply for the future, the exchange of the pipe system was initiated in 2011/2012.

In the course of this modernization in the Elisabethenstollen duct, "it" was discovered. For more than 50 years a Düker gate valve had been doing its job faithfully. Now it is out of service. And just like in real life, the young generation of gate valves will take over its work in the Bad Homburg Elisabethenstollen duct.

With a modern design and adapted to today's production standard, these innovative construction characteristics can be found almost unchanged in today's gate valve generation type 4004 by Düker. They guarantee quality, functionality, economy and a long lifespan.

A tour through the Düker manufacturing plants – just like the Bad Hom-burg water supply plants - helps anyone realise that tradition and mo-dernity do not exclude each other. From construction and design to the finished product, for decades – Made by Düker.

DISCOVERIES Transport of gate valves

in the 1950s

Düker gate valve –after 50 years of use!

The gate valve that was found is a Düker gate valve from long ago. Manufacture approxi-mately 1958/1959. Construction: resilient-seat-ed with bellows membrane, stem bearing with O-rings, and enamel inside as a protection against corrosion and incrustation. A com-pletely new construction and technology in its time – ground-breaking in valve technology, it would become a national and international standard later on.

14 15

PRODUCT INNOVATIONS

"Almost anyone can think up an idea. The thing that counts is developing it into a practical product.“(Henry Ford)

Backflow preventers type RV 80 have been on the market since 1967 and are now being replaced after 50 years of service. Non-slam check valves are part of the backflow preventer family. They are used wher-ever a flow direction is defined and the backflow of the medium is to be prevented. Typical application areas are e.g. behind pumps, com-pressors or blowers.

The ideal backflow preventer should · cause only minimal pressure loss in the flow direction· reach the completely open position at minimal flow velocities· seal tightly and immediately at the minimal back pressure,

in case of energy failure or flow reversal· have as short a closing time as possible in order to keep

the danger of pressure surges as low as possible in caseof flow reversal

· follow the operating conditions without inertia – opening/closing –· be suitable for all installation positions and· be maintenance-free.

Last but not least, the protection of our environment requires more and more sophisticated process technologies in water supply plants and pump stations. This has raised the requirements on the backflow preventers considerably.

The newly constructed Düker non-slam check valve type 8015 fulfills these requirements to the full extent.

· Compact design.· Face-to-face length as per EN 558, basic series 14.· Nominal pressure up to PN 40.· Suitable for all installation positions through adjustable springs.· Flow-optimised profile with a completely rubberised sealing disc.· The sealing seat on the valve disc guarantees tight sealing at low

back pressure rates.

When completely opened, from 1.5 m/s, the valve disc reposes against a centred, unmovable streamlined body. This stabilises the valve disc so it can be used without problems for the highest or low-est flow velocities. Thanks to the very favourable flow pattern there

are only minimal pressure losses. An economy of pressure energy, pump output and electricity.

The Düker non-slam check valve type 8015 reaches its short closing time through the use of a spring which supports the closing move-ment of the valve disc. This reduces the risk of pressure surges – e.g. when switching off pumps.

The valve design is maintenance-free. If required a repair is possible without problems.

The all-around Düker etec enamelling of the body parts inside and outside rounds off the special sustainability of the non-slam check valve type 8015. This corrosion protection offers a particularly high lifespan and therefore also enhances the durability of the closing and opening function. Even after its useful lifespan, the enamelling al-lows for a simple and environmentally friendly disposal and reuse.

The newly designed Düker non-slam check valve type 8015 guaran-tees a high measure of operating safety for a reliable, undisturbed operating of water treatment plants and pump stations. Functional safety, long lifespan and technological efficiency go hand in hand.The Düker name stands for sustainable values: performance – efficiency – innovation – environmental protection.

THE HYDRAULICALLY

OPTIMISED BACKFLOW PREVENTER

TYPE 8015 IS LAUNCHED!

THE NEW LINE:DÜKER NON-SLAM CHECK VALVE TYPE 8015

Pump station Honscheid, water supplier WTV Siegburg

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PRODUCT INNOVATIONS

Areas of application:· Pump stations· Industrial applications· Water collection· Water extraction · Water distribution

Medium:· Potable and untreated water up to 60 °C

Design:· Flange connection measures as per EN 1092-2· Face-to-face length as per EN 558-1, basic series 14· Length compensation to alternative face-to-face lengths

is possible

Design versions:· Horizontal and vertical from below or· Vertical from above

Corrosion protection:· Body and body insert all-around enamelling with

Düker etec enamel as per EN ISO 11177, shade cobalt blue· All parts in contact with the medium in accordance with

the elastomer guideline and DVGW worksheet W 270

Technical characteristics:· Tightness from a back pressure of approx. 500 mbar· Leakage rate A as per EN 12266· Complete opening depending on the nominal diameter between

1.5 m/s and 2 m/s· Closing time under atmospheric conditions: <0,1 s

Technical enamel, the old, rediscovered and state-of-the-art surface protection for valves and fittings in water supply systems, has been ennobled.

In October 2016, the former German standard DIN 51178 becameEN ISO 11177:2016-10:

The EN ISO 11177:2016-10 standard was developed by the Technical Committee CEN/TC 202 "metallic and other inorganic coatings", in co-operation with the Technical Committee ISO/TC 107 for the same subject. The corresponding German standard committee is the task force NA 062-01-63 AA "Testing of Enamels and Enamelling" in the DIN standard committee material testing.

This document states the requirements on the product quality of enamelled valves and pressure pipe fittings in the untreated and po-table water supply. It is not valid for enamels for chemical industry and appliances. The requirements on the product quality consider

realistic demands and conditions that an enamelled valve or fitting may have to face within its lifespan. The standard was developed on the basis of the guideline of the German Environmental Authorities (UBA) regarding the hygienic evaluation of organic materials in con-tact with potable water (KTW guideline).

EN ISO 11177:2016-10

Vitreous and porcelain enamels. Inside and out-side enamelled valves and pressure pipe fittings for untreated and potable water supply. Quality requirements and testing.

DIN: EN: ISO:national German European worldwide

Compared to DIN 51178:2009-10, only the following modifications were made:a) transformation into EN ISO; 1:1b) updating of normative references

NEWS FOR INSIDERS

WHAT IS A STANDARD?

Standards are not laws. They are recommenda-tions. They are considered ordering instruments for the business world. They serve companies and organisations to adapt their products to each other. They help reduce international trade barriers.

Example: The USB connection on the computer is the same all over the world – the interface is standardized.

GOOD TO KNOW!

1

1

2 34

5

Materials

Body and body insert – ductile cast iron EN-GJS-500-14

Disc valve – ductile cast iron EN-GJS-500-14, completely rubberised

Guide rod and threaded bush stainless steel 1.4057

Spring stainless steel 1.4310

Guidance bush polymer

2

1

3

5

4

Hydraulic pressure loss coefficient

pres

sure

loss

coe

ffici

ent (

-)

flow velocity (m/s)0

0,1

1

10

100

1 2 3 4 5

Regionalverkaufsleitung

18 19

HELLO DÜKER!

EXPORT MANAGEMENT

Gerald WernerTel. +49 6093 87-250E-Mail gerald.werner@dueker.de

AREA SALES MANAGEMENTNORTH-EASTERN EUROPE SOUTH-EASTERN EUROPE

Thomas EckelTel. +49 6093 87-211E-Mail thomas.eckel@dueker.de

CONTACT

Zlatko PijetlovicTel. +49 160 1767394E-Mail zlatko.pijetlovic@dueker.de

Nicole PautkinTel. +49 6093 87-181E-Mail nicole.pautkin@dueker.de

CUSTOMER SERVICEAPPLICATION TECHNOLOGY

Dorothee FleckensteinTel. +49 6093 87-262E-Mail dorothee.fleckenstein@dueker.de

Ivonne KellerTel. +49 6093 87-282E-Mail ivonne.keller@dueker.de

Waldemar GaninTel. +49 6093 87-279E-Mail waldemar.ganin@dueker.de

PUBLISHER:Düker GmbH

D-63846 Laufach, Germany

RESPONSIBLE EDITOR: Ursula Vogler

Reprint and photomechanical reproductionof any kind, even partially, only withwritten permission of the publisher.

EDITORIAL ADDRESS: Düker GmbH

Dept. „Wasserspiegel“Hauptstr. 39–41 · D-63846 Laufach, GermanyTel. +49 6093 87-560 · Fax +49 6093 87-8560

E-Mail sales.fittings-valves@dueker.dewww.dueker.de

LAYOUT AND TYPESETTING:GleisNeun GmbH

www.gleisneun.de