Annual Journal 54 – 2020

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Themes, Authors, Abstracts, Keywords (Details)

Annual report 2019 and the perspective in 2020
by Manfred Künze, Christoph Aigner and Christoph Bennerscheidt

Climate change has become the dominant issue in the people’s minds. It is to be hoped that the activities of the German government to reduce CO₂ emissions will soon come to fruition. The climate protection programme will have dramatic consequences for the current structure of our economy. On the one hand, the strengthening of the circular economy accommodates the principle of recycling in foundries, while on the other hand, serious investments have to be shouldered in the conversion to melting units that can be operated with renewable energy instead of coal, combined with the urgent demand for increased energy efficiency and the omnipresent task of saving energy. Further tasks of the association are the supervision of national and international regulations, the development of joint projects

– Digitisation
– Resource efficiency
– Sponge City

and the creation of a quality specification for the RAL quality label “Ductile cast iron pipe systems – pipes, fittings and valves “ in Department 8 of GET – Gütegemeinschaft Entwässerungstechnik e. V.

The foundry industry = recycling industry
by Mario Mackowiak

The climate package adopted by the German government in December 2019 stipulates a 95 % reduction in CO₂ emissions in all sectors by the year 2050. Closely bound up with this is the law on circular economy, which has already been in existence for some time and requires closed material cycles in all areas, including the construction industry sector. The foundry industry has long been adhering to this principle of sustainability: these days foundry products are extensively smelted from scrap metal, though still to a large extent in cupola furnaces which emit considerable volumes of CO₂ because the energy they require for smelting is obtained from the combustion of coke. But the trend is going towards electric induction furnaces which use electricity EADIPS FGR DUCTILE IRON PIPE SYSTEMS 54 7 from renewable sources. Additional tasks lie in the optimisation of all processes in the foundry: for example, considerable potential for energy saving can be envisaged when it comes to blasting the castings. And broadly closed circuits can also be achieved by recycling used moulding and core sand. The manufacturers of ductile cast iron pipe systems have long since set the standards for resource efficiency with their long working life.

55 km drinking water pipeline over 550 meters altitude
by Patricia Pfister

Mongolia, a land of extremes in terms of climate, distances, population, topography – nothing resembles the conditions in Europe. Population density alone is 120 times lower than in Germany and distances are gigantic. This is an area which needs some ingenious logistics when it comes to laying a 55 km long drinking water transport pipeline for a provincial capital with 30,000 inhabitants. Responsibility for planning and transport, the construction of a water purification plant, pumping stations and the pipeline were placed in the reliable hands of Tiroler Rohre GmbH, the Austrian manufacturer of ductile cast iron pipe systems. Thus, interface problems were avoided which, because of the climate-related narrow time window of six months, could have had catastrophic effects. The article clearly shows how extreme requirements can be elegantly handled with ductile iron pipes.

Large-dimension interim pipeline for the inner city
by Lutz Rau and Jens Große

For a long time now Berliner Wasserbetriebe has been a pioneer in the development and establishment of new construction technologies. One only has to think of the replacement of existing drinking water pipelines, half of which is already done using the trenchless technology according to established technical rules. A similar development is happening with the replacement of existing wastewater pressure pipelines where sewage transport has to be maintained with the help of temporary bypass pipelines. A broad range of experience has been gathered in recent years for the planning, construction, operation and dismantling of these interim pipelines, which are essentially above-ground, and this experience has been translated into draft technical regulations or standards. The most economical solution which has emerged for straight sections is the use of thrust-resistant ductile iron pipes which are quick and simple to assemble and then dismantle and which can also be used again in other phases of construction. Road crossings are achieved by means of culverts using the welded steel pipe technique. Based on a project implemented in Berlin-Pankow, the article allows a glimpse into the “writing workshop” for Berliner Wasserbetriebe’s standards.

The right pipe in the right bedding
by Jürgen Rammelsberg

This article provides a summary of the most important technical solutions for the external protection of ductile cast iron pipe systems and describes the development of regulations in this sector over the last 50 years. And of course there is a look at future new areas of application for ductile cast iron pipe systems: they are highly topical because they demonstrate one way of alleviating the climate emergency in our cities, which is already covered by the applicable regulations (see the article entitled “Implementing the sponge city principle” on page 46 ff.).

A challenge: leak detection on long-distance pipelines
by Manuel Görzel

With the “Ortomat MTC” correlator from vonRoll hydro (service) gmbh the scope of application of correlation technology for detecting leaks in pressurised water pipelines has been considerably extended. The typical measurement technology previously used was limited to urban drinking water networks as these always have easily accessible application points for the microphones. In addition, with urban networks of this kind, the measurement distances are relatively short so leak noises are readily detectable. But this is not the case with transport pipelines: their access points are often 1,000 m and more apart and may be without any direct radio communication between them; also noise from pumping or transfer stations may have an interfering influence. The new type of measurement technology overcomes these disruptions and has been tried and tested by major water associations.

Quality leap for TRM cast iron pipes
by Roland Gruber

The immense significance of external protection for ductile iron pipes which is highly effective both mechanically and chemically has already been described elsewhere in this issue (“The right pipe in the right bedding”, page 28 ff.). It is therefore no wonder that another cast iron pipe manufacturer is grappling with the production technology for cement mortar coating and, after two years of intensive research and development, now offers a pipe with optimum protection. The advantage of the so-called “ZMU-Austria” coating will be seen not only in urban drinking water networks, where mechanical resistance accounts for a considerably longer useful life as compared with plastic pipes. Also in alpine areas with pipelines for hydroelectric power stations and snow-making equipment, the ductile iron pipe with “ZMU-Austria” coating is unbeatable: when it comes to sustainable efficiency, there is no need for special logistics for the bedding material as the stony trench excavation material can simply be reused without complication. And the increasing importance of the trenchless technology for laying pipes plays right into the hands of the new product.

A new transit pipeline for the Birs Valley
by Marco Nussbaumer

In supposedly secure supply networks, weather events caused by climate change can cause weak spots which need to be dealt with. This is also the case in the landscape of the Canton of Basel where, in Summer 2007, torrential rainfall in the catchment area of the River Birs flooded numerous locations and polluted the groundwater by releasing fuel oil and other harmful substances, to such an extent that the pumping stations and treatment plants had to be taken out of operation. It was necessary for many communities to be supplied with drinking water from tankers. As a consequence of this incident, a decision was made by the relevant authorities to create a redundant system, which dramatically increased security of supply in the Canton of Basel: a 2.5 km long “Birs transit pipeline” consisting of DN 500 ductile iron pipes with cement mortar coating and a new pumping station now mean that the drinking water supply is secure for the residents of the Birs Valley in the Jura Mountains.

Spectacular pipe mounting in the vertical
by Marco Nussbaumer

Now as ever, the alpine environment contains an enormous potential for the production of renewable energy by means of small hydropower plants. Their penstocks have evolved into the typical area of application of ductile iron pipe systems as, under the prevailing conditions locally, this combines the ideal pipe material with the optimum connection technology. Sections with extreme inclines often lie within almost inaccessible rocky areas and the energy generated increases as the height differences become greater; installation in steep rockfaces with the help of helicopters is common practice. External protection of the pipes with cement mortar allows the chunky bedding material to be reused; transporting bedding sand to the site would otherwise be technically and economically impossible. So the ductile iron pipe has become a symbol of sustainable energy production – and now also in Finhaut.

Implementing the sponge city principle
by Christoph Bennerscheidt

Climate change has unavoidably arrived: the last two Summers of 2018 and 2019 were characterised by new records as regards temperature, dryness and hours of sunshine. And this was not merely in Germany but also in many countries of West Europe. It is not only the trees in the forests which have suffered; trees in our towns and cities, with their important function of influencing the urban microclimate, have suffered above all.

Under these circumstances it is vital that urban trees are given the root space necessary for successful growth right from the point of planting and are not imprisoned in reduced tree pits with the lifelong decline which this involves. The underground space beneath our roads is crowded with pipelines, sewers, shafts and other structures. There often remains much too little space there for the roots of a tree to be able to develop into a splendid specimen. Also, water can only penetrate to an insufficient extent because the surfaces above are tightly sealed. In fact, it often happens that water is routed away from the tree via rainwater drainage gutters. There is a simple principle which applies here: pipelines with root-resistant connections and robust external protection are embedded in the coarse substrate. In this way the street trees benefit from a well aerated planting location in which the rainwater is routed from the sealed surface and stored. The trees have enough space for their root growth, they can take up the water temporarily stored there and evaporate it through their crowns, thereby cooling the heated cities. Pipelines in robust ductile cast iron pipes with root-resistant connections produce the ideal condition for realising the so-called sponge city principle.

Ductile cast iron pipe as a problem solver
by Gennady Walder

A hydraulic power station equipped with two Francis turbines in Albania will contribute to covering the increasing electricity demand. A third turbine is housed in the barrage of the River Devoll and operates via a 354 m long penstock DN 800, the lower waters of which are treated for the supply of drinking water. The installation in the narrow supply tunnel at the foot of the barrage, the operating pressure PFA of 25 bar and the restrained connections using the tried and tested BLS^® system are simple tasks to solve with ductile iron pipes.

Energy networks with ductile iron pipes
by Roger Saner

With the energy stored in the waters of the huge Swiss lakes there is considerable energy potential available for the neighbouring communities. This can be rendered usable with the help of heat pumps. The pipelines installed for transporting the lake water consist of ductile iron pipe systems, which are best suited for this purpose: they are protected inside and out against corrosion and their large hydraulic cross-section combined with a low pipe wall roughness results in low operating costs. In addition, improvements in the efficiency of heat pumps and heat exchangers has a positive effect. Ductile iron pipes are easy and secure to install, in short: the ductile iron pipe system offers the best conditions for the transport of low-temperature district heating.

New generation of soft-seated gate valves
by Matthias Müller

The market penetration of PE pipes has also resulted in a change in the construction of fittings: flange connections, which were formerly standard, are losing their significance; a fitting which has already been equipped in-works with a short PE-pipe which can be welded into the pipeline is considerably easier to handle during installation. The problematic transition between metal and plastic therefore shifts from the construction site to the quality-controlled production by the manufacturer of the fitting.

Together in the future
Interview with Stefan Neuhorn

In recent years the Swiss company vonRoll hydro ag has concentrated and restructured its skills in Germany. As from 1st January 2020 the German sectors are now moving even closer together. The three distribution companies VONROLL, DUKTUS and KEULAHÜTTE are being brought together as vonRoll hydro (deutschland) gmbh & co. kg. In an interview, Dipl.-Ing. Stefan Neuhorn, Managing Director of vonRoll hydro (deutschland) gmbh & co. kg explains what is going to be different and better in the future because of this measure.