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World’s largest plastic pipe will help to cut pollution in Birmingham

Wed, 03 Mar 2010 08:25:00 -0500

Severn Trent Water is using the largest plastic pipe available on the market to help reduce pollution as part of a sewer improvement project in south Birmingham.

Water company Severn Trent in consultation with Barhale Construction plc has chosen Weholite, the high density polyethylene (HDPE) pipe manufactured by Asset International Ltd, to reduce the risk of pollution to the River Rea.

When complete, the £3.3 million large-scale project will upgrade the existing sewerage system through Cannon Hill Park near Edgbaston, Birmingham. This will include improving its resilience in storm conditions by rebuilding an overflow chamber and adding a storage tank. This will reduce the amount of overspill into the river during storm conditions and improve the water quality of the River Rea.

500 metres of 3.5 metre diameter Weholite pipe will be laid in 47 metre long rows interconnected by nine manifold sections to form a storage tank during periods of bad weather. The end pipe will act as the primary entry point for the water. The inlet will then release the water into eight adjacent pipelines. The tank incorporates a sewage pumping station to return flows into the sewerage system.

Severn Trent’s original design considered using a concrete specification for the new storage chamber. However, due to cost and the length of time this would take to construct, the company looked for an alternative material. By using Weholite instead of concrete, the project saved 2,600 tonnes of CO2 when the overall process, including manufacture, transportation and the laying of the pipes, is considered – helping to contribute to Severn Trent’s carbon reduction targets.

Contractors Barhale will be laying the pipes for Severn Trent. Barhale site manager, Roger Light, said: “Weholite pipes are lightweight and therefore easy to lay. By using plastic rather than the original concrete specification we’ll be able to reduce the time spent on site by six months.

“Also a number of health and safety issues are removed for us as there is much less requirement for heavy-lifting machinery on site for installation.”

The overall project in south Birmingham will be completed in March 2010.

Project coordinator for Severn Trent Water, Wayne Ellis, said: “Our sewerage system through Cannon Hill Park has been serving the community for many years. However, it is no longer able to cope with modern demands.

“During heavy rainstorms an overflow of sewage and rainwater spills into the River Rea and causes pollution. We want to reduce these occurrences and we are committed to helping clean up the river by reducing pollution from our sewers.”

Managing director at Asset, Simon Thomas, said: “We have successfully worked with Severn Trent on many projects, all of which have used our Weholite pipes.

“This project was the largest order to date for our new 3.5 metre diameter pipe and in total there will be 34 sections of pipe used in the project, all of which will be welded on site. Weholite is very versatile and particularly effective for projects of this nature because the pipes are prefabricated and lightweight, which means they can be quickly and easily laid on site.”

Download the latest Pipeworld Issue

Wed, 27 Jan 2010 06:18:00 -0500

Pipe World is the KWH Pipe customer journal and it is distributed to our partners around the world through our units. Latest issue available to download now.

Click here to download your free copy. In this issue you can read about:

Mobile production of WehoPipe
Flexible pipes in district energy networks
New pipelines for a growing Gibraltar
Communal wastewater treatment plant for a village in Norway.
The CombiGolfe power plant in France

Click here to review back issues

Weholite prevents flooding in Preston Village

Fri, 22 Jan 2010 07:38:00 -0500

Northumbrian Water has invested £3.7 million into an innovative water management solution that will reduce the risk of flooding in Preston Village, North Shields.

The 30-week flood alleviation project has opted to use Weholite, the high density polyethylene (HDPE) pipe manufactured by leading water management solutions provider Asset International Ltd.

Around 200 homes are set to benefit from the project, of which 64 have previously been flooded during periods of very heavy rainfall. Work is due to be completed mid-December this year.

Two kilometres of Weholite pipeline will be positioned directly under the rugby pitch at North Shields Rugby Club, with one 1.8 metre diameter pipeline acting as the primary entry point for the water. The pipe will then release the storm waste-water into 15 adjacent 1.5 metre diameter pipelines that will form storage tanks. The storm waste-water will then be slowly released back into the sewerage system and treated before being returned to the environment.

Design consultants Mott Macdonald Ltd specified the use of Weholite for this scheme.

Contractors Lumsden & Carroll Construction Ltd. will be laying the pipes for Northumbrian Water. Site manager, Ralph Dunn, said: “The Weholite pipes are lightweight and therefore easy to manoeuvre, because of this we have kept disturbance to a minimum which is important in residential areas.

“As the pipe could be easily offloaded from the lorry and placed directly into the trench, we removed a number of health and safety issues and saved a considerable amount of time.”

Weholite has been proven to have a lower carbon footprint than other traditional pipe materials due to a number of factors, including its UK manufacture and its lightness which results in reduced transport costs and much less requirement for heavy-lifting machinery on site for installation.

Project manager at Northumbrian Water, Graeme Ridley, said: “Reducing the risk of flooding is one of our top priorities and it is vital that the solutions we choose are effective and efficient. Weholite has been tried and tested on some of our previous flood alleviation projects and has proved to be extremely effective. Due to the lightness of the product it is easy for us to install and construct which save us a great amount of time.”

Managing director at Asset International, Simon Thomas, said: “We have worked closely with Northumbrian Water to successfully complete three flood alleviation projects over the last two years.

“The Preston Village project is a great demonstration of the versatility of our Weholite product and how it can be adapted to provide bespoke solutions for flood alleviation.”

Gwent ‘Dragon’ Sparks Entrepreneurial Spirit in Teenage Learners

Fri, 22 Jan 2010 07:35:00 -0500

A real life business ‘dragon’ helped Gwent learners to fire up their desire to run the enterprises of the future this Global Entrepreneurship Week (November 16 to 22).

Simon Thomas, managing director of Newport-based water management solutions provider, Asset International, visited the ‘Learn About’ education and training centre in Risca on Wednesday November 18 to judge a Dragon’s Den-style competition.

The contest, based on the hugely-popular BBC series, saw trainees bravely pitching their creative ideas to Mr Thomas in a bid to secure a cash prize.

Ideas included a community art bus, which would involve an artist travelling around to teach skills like pottery and watercolour, a ‘butter stick’, which looks like a Pritt Stick and is designed for the ”lazy man” to spread his butter easily, and a silent dog toy, whose squeak is so high that it can only be heard by dogs and not by their owners.

Mr Thomas also delivered an inspirational talk to youngsters about how his innovative ideas and self-motivation helped him rise from apprentice engineer to managing director in the successful manufacturing firm which makes high density polyethylene pipe systems for use in civil engineering projects

Mr Thomas’ visit to Learn About during the awareness week was arranged as part of the centre’s Welsh Baccalaureate Qualification course. The qualification, which has been delivered at the Risca centre since September, requires learners to take part in a team enterprise activity which helps them to understand how businesses work and develops their entrepreneurial skills.

The qualification, which is currently being delivered to more 35,000 learners in 168 schools, colleges and training centres throughout Wales, adds a valuable new dimension to the subjects and courses already available for 14 to 19-year-olds.

The qualification, introduced by the Welsh Assembly Government, aims to transform learning for young people in Wales. It combines personal development skills with existing qualifications like A levels, NVQs and GCSEs.

Dewi D’arch, skills trainer at Learn About, which is part of Wales’ largest work-based learning company ACT, said: “Global Entrepreneurship Week provided us with the perfect opportunity to really drive the team enterprise element of the Welsh Baccalaureate Qualification and we are extremely grateful to Mr Thomas for coming to the centre and helping us to do that.

“Hearing someone like Mr Thomas speak has been a real eye-opener for our learners and I firmly believe that his flair for business and enterprising spirit has had an immensely positive impact on them.

“Pitching their ideas to Simon evidently took some of the learners right out of their comfort zones, but this experience will be of tremendous value to them when they venture into the world of work.”

Mr Thomas said: “I have been really impressed with what I have seen today. The ideas have been really creative and it’s obvious a lot of effort has gone into developing them. The Welsh Baccalaureate is an extremely valuable qualification, in the way that it allows young people develop so many skills, such as business and communication skills.”

London’s water system upgrades with Weholite

Fri, 22 Jan 2010 07:27:00 -0500

The UK’s largest water and wastewater services company is upgrading its process system to improve the drinking water supply to more than 1.1 million residents across London and the Thames Valley.

Thames Water has invested £11.3million in overhauling and upgrading the drinking water processing system on its site at Walton-on-Thames in Surrey. The project, which will allow an extra 55 mega litres of water through the system each day, will use leading water management solutions provider, Asset International Ltd to provide their Weholite high density polyethylene (HDPE) pipes for use in the bulk recycle pipeline.

Engineering, consulting and construction company, Black & Veatch, opted for the Weholite pipes manufactured by Asset. Black & Veatch’s site manager, Max Turnbull, said: “Asset’s Weholite pipes are lightweight and therefore are easy to handle, which saves us time and money that would have been spent on heavy lifting equipment when laying the pipes.”

The current pipe system at the site distributes 80 mega litres of water a day to London and the Thames Valley, the new larger 1.2 metre diameter pipes will allow the water treatment works to provide 135 mega litres of water on an average day and 165 mega litres at peak times.

Weholite has been proven to have a lower carbon footprint than many other traditional pipe materials thanks to a number of factors including its UK manufacture and its lightness, which results in reduced transport costs and much less requirement for heavy-lifting machinery on site for installation.

Project manager at Thames Water, Mark Bulpett, said: “Thames Water has successfully worked with Asset on a number of previous projects. On projects such as this we always look for the pipework to be a high quality product that is cost effective and right for the job.

“Plastic pipes are lightweight so they remove a number of health and safety issues when it comes to handling them and for us that is a definite bonus.”

Weholite pipes are extremely versatile which allows them to be easily managed on site as slots are inserted simply into the plastic for quick placement.

Managing director at Asset International, Simon Thomas, said: “We are delighted that Thames Water and Black & Veatch chose our Weholite pipes to complete their project at Walton-on-Thames.

“We have successfully completed around 10 drinking water projects across the UK over the last three years. Working with the major water companies, including Thames Water, Wessex Water, Anglian Water, Welsh Water and Scottish Water, has given us experience of the industry, an insight into site conditions and into what both the water companies and contractors are looking for.

“The Weholite system is becoming the product of choice for new projects and upgrades within the water industry thanks to its high quality, sustainability and design in value engineering aspects.”

Why there’s more to plastic pricing than costs at the petrol pump

Thu, 14 Jan 2010 04:48:00 -0500

The myth that the price of plastic should correlate directly with the price of oil is a wide misconception and one that needs to be debunked, (says Asset International’s Dr Vasilios Samaras). It’s a common belief in the water and construction industries that the price of oil dictates the price of plastic commodities and products and therefore impacts on project costs.

But the idea that the price of plastic should correlate directly with the price of oil is a wide misconception and one that needs to be debunked. Debunking Myths In many cases, it is the price of the feedstock, ethylene (in the case of polyethylene) that has the bigger impact on the price of plastic. Plastic is derived from recuperated (or ‘cracked’) naptha, a simple refining residue, which once was just flared off. Ethylene (the building block of all types of Polyethylene, the most common type of plastic) is a by-product of oil, so it’s essentially putting a waste product to good use, rather than polluting the atmosphere.

Feedstocks have their own supply and demand and therefore their own market price. It is this market price that more directly affects the price of plastic as the feedstock price is the largest cost in producing the plastic raw materials. So whilst the oil price has halved since its peak at $140 per barrel in September 2008, feedstock costs have remained relatively high sustaining polymer prices at high levels. The situation is made worse by the fact that it is difficult to precisely control crackers to match demand. This can often lead to situations of over or under supply which can lead to rapid changes in feedstock prices and therefore polymer prices. This is the case at the moment when despite poor demand for plastics due to the global recession, feedstocks are tight due to cracker shutdowns or outages. The price of feedstock has therefore been rising keeping plastic prices high. Yes, the price at the pump does have an effect on transportation costs, but that is way down the process production line, and has marginal impact on project costs. While it is easy to see why the oil-plastic-pricing assumption exists when 99% of all plastics are derived from crude oil (yet only 4% of all crude oil produced is used to make plastics), in fact many other elements impact ethylene prices.

Today, the mechanical properties of plastic, such as its robustness and abrasion resistance, make it an essential product for everyday use such as packaging and carrier bags, and also for use in pipes that are tough enough to use in marine outfall projects and flood alleviation schemes. Supply and Demand With its use in a multitude of applications, it’s easy to see why there is, for the long-term, growing demand for plastic, and particularly polyethylene, in the UK and world-wide. In 2008, all types of polyethylene experienced decline in consumption, with the second half showing an unprecedented demand crash, which can largely be put down to the current global economic climate. As the demand for plastic has increased in recent years, particularly in China and the developing world, a situation of undersupply has arisen whereby the demand for plastics outstrips available supply.

The long-term nature of petrochemical projects means that there is a lag before new plants come on stream to create additional supply to meet this growing demand. This shortage has led to historically high prices. Acts of God Of course factors outside of human control can have a huge impact on the supply of oil and this in turn will directly effect the supply of polyethylene. Factoring in the lengthy production cessation periods that environmental disasters can have on oil production, demand can rapidly overtake supply. A good example is Hurricane Katrina which struck US shores in August 2005. In preparation for her arrival to the US, 17.1 million barrels of oil were shut in and therefore the production of polyethylene was postponed. The production of oil in the Gulf of Mexico fell by 1.4 million barrels a day. This accounted for 95% of the daily production of oil.

Two weeks after Hurricane Katrina struck the Gulf of Mexico over 120 oil and gas platforms were still closed. Nearly 60% of the gulf’s daily production of oil and gas remained blocked from the market due to the evacuations of personnel in preparation for Hurricane Katrina. By September 2005, 21 oil refineries, a combined total of 47% of US distillates, were still not functioning. Six more of those refineries were relit within the following 30 days, but the remaining four refineries all suffered serious damage. None of them returned to full capacity by the end of the 2005. The relighting and rebuilding processes would cause the US a deficit of 25% of the total supply. It’s easy to see how quickly the shift from the over-supply to over-demand for polyethylene can happen by looking at the effect of Katrina. Throughout this period, demand for polyethylene dramatically exceeded supply, and as a result prices rocketed.

This pattern can be seen across the globe following large-scale natural disasters. Similarly, this pattern appears during periods of political unrest and international conflict. Unfavourable Exchange Rates An added factor to the price of polyethylene is the weak performance of sterling against major currencies such as the US dollar and the euro. UK manufacturers are effectively paying more for the same amount for polyethylene now than they did even a year ago.

So What Does This All Mean For UK Plastics Manufacturers and Their Water Industry Clients? The ever and sometimes rapid fluctuation of polyethylene prices makes life difficult for UK manufacturers as managing director of Asset International Limited, manufacturers of Weholite pipe, Simon Thomas, explains; “In the past year, we have seen polyethylene prices increase by as much 40% within a time-frame of two months, and despite the greater cost to us as a manufacturer, we have had to absorb those costs and honour previously agreed quotes rather than passing them on to our clients. “This is not an ideal situation in the long-term, which is why we are constantly evolving and innovating our Weholite pipe designs to maximise the value to our clients and minimise the impact of plastic prices.” The Future’s Looking Brighter The good news is that supply and prices for ethylene will get better.

There are currently plans for a substantial amount of new oil production plants in the Middle East in the next five years, which means that the supply – demand ratio will swing dramatically in favour of the consumer. With a competitive market, comes more competitive prices, then. Industry experts expect economic growth to recover in the next few years, and as the world’s industries demand more plastic, more polyethylene will be produced to meet consistent demand.

As Katherine White of polymer distribution company Plastribution says; “We should see the start of a wave of linear low-density polyethylene (LLDPE) and high density polyethylene (HDPE) capacity additions over the period 2009 to 2012. Polypropylene will also see unprecedented new capacity of over 5m to come on stream during 2009-2011. This is good news for manufacturers like Asset International and their clients in the water industry in the long-term." FACT BOX COPY Green Plastic Facts Did you know: • Plastics have reduced the average weight of cars by 200kg, thereby economizing 500 litres of petrol every 100,000km. • 35 plastic bottles can be recycled to produce one polar fleece jacket • Plastics have helped to reduce the weight of cars by 200kg, thereby economising 500 litres of petrol every 100, 000km. • Plastic gas and water pipes have a guaranteed life of at least 50 years ENDS Photos Attached – 1) The Petro Rabigh oil plant, which is located on the Red Sea, on a 3,000 acre site 2) Plastic pipes in action – 2.1m Weholite pipes used in Northumbrian Water’s Flood Alleviation scheme in Shiremore, North Tyneside. 3) Plastic is tough enough to use in marine outfall projects, such as this sewage outfall in Raahe, Sweden.

PRESS RELEASE: AMP 4 Projects Flood in for Asset

Thu, 17 Dec 2009 05:45:00 -0500

AMP 4 Projects Flood in for Asset Newport based water management solutions provider Asset International Limited is investing in new technology and expanding its manufacturing facilities to meet with ever increasing demand for its high density polyethylene pipe systems known as Weholite. Following last year’s record performance, Asset is now looking to build on its growing reputation in the marketplace and has already secured forward orders to the value of £1.5 million for use in phase four of the water industry’s capital works programme known as AMP 4.

Simon Thomas, Director of Asset commented on the flow of new contracts: “The aim of phase 4 of the Asset Management Programme which runs to 2010 is to improve the water infrastructure throughout England and Wales. Water companies have learnt many lessons from the previous phases of this programme and are now looking for long term durable solutions that offer best value and sustainability. We offer a complete service from concept right through to installation and our Weholite storm water and sewerage attenuation tanks are bespoke designed solutions that offer many benefits to the demands of the water companies.

As well as continuing to work with existing clients, the uptake of our systems by new customers has been amazing – a just reward for a hardworking team.” In order to respond to the increase in demand, Asset is installing a £1 million state of the art production line that will not only double its capacity but allow it to manufacture the World’s first 3.5 metre diameter Weholite pipe. Mr Thomas added: “We will continue to invest in product and process development to ensure we stay right at the cutting edge of HDPE water management technology as we strive to achieve our main goal of becoming a world class manufacturer and solutions provider.”

The Strength of Flexibility

Thu, 17 Dec 2009 05:38:00 -0500

As the debate regarding the use of concrete over plastic continues to remain high on the agenda across the water management industry, the very specific strengths, benefits and weaknesses of both materials are tested vigourously on a regular basis.

Dr Vasilios Samaras of Asset International Ltd, former graduate of the Polymer and Process Technology School, part of the Engineering department at Swansea University (one of only three Universities to have gained the 5* RAE rating), looks here at the specific benefits that can be offered through the use of plastic, in this case Weholite, in water storage systems and pipe infrastructure. Weholite is a large diameter, gravity or low pressure structured wall pipe made from high density polyethylene (HDPE) resin. The low-pressure, high-technology pipes are extremely tough, flexible, chemically resistant, and offer an alternative solution to other forms of traditional pipe systems, including concrete and GRP. With Weholite, raw material properties have been combined with advanced product technology to create a lightweight engineered pipe with superior loading capacity.

It is commonly used to convey liquids or air, underground, above ground or under water in low pressure applications up to 1.5 bar internal pressure. The material can be used across a range of applications, including surface drainage, foul sewers, inter-process pipework, culverts, attenuation tanks, ducting and outfalls. A flexible pipe is by definition, a pipe which will deflect when subjected to external loads. It is a commonly held assumption that any deformation of a plastic pipe is inherently detrimental and indicative of failure of the pipe to perform properly. This is a fundamental misconception. On the contrary, it is actually an advantage, and demonstrates the strength behind the flexibility of Weholite and HDPE materials. Flexibility in buried pipes is a desired attribute. Understanding how the flexible pipe relates to its neighbouring soil – thereby establishing a functional pipe/soil composite structure, is key to successful design. Under load, even the most flexible pipes, may only experience small amounts of deflection, provided they are installed correctly. In general, during the installation of a buried pipe, backfill is placed around the pipe in the trench. Irrespective of how well the backfill is compacted adjacent to the pipe (side-fill) during installation, further compaction develops with time.

Additional settlement then occurs in the side-fill resulting in an increase in deflection for a flexible pipe. A rigid pipe which does not noticeably deflect, will be continuously subject to an increased load. The interaction of pipes with soil A buried pipe and its adjacent soil will attract earth loads and live loads in accordance with a fundamental principle of structural analysis: stiffer elements will attract greater proportions of shared load than those that are more flexible. In other words, the more flexible pipe will attract less crown load than the rigid pipe of the same outer geometry.

This is because the rigid pipe does not transmit the loads into the surrounding material but the loads are transferred through the pipe wall into the bedding and therefore are subjected to much greater loads than the flexible one. In general, flexible pipes rely upon their deformation from imposed loads to mobilise the support of embedment material on both sides of the pipe. Their primary structural function is distributing the imposed vertical loads to the surrounding soil.

Only a small portion of the imposed loads are actually carried by the flexible pipe itself. Instead, load is transferred to the surrounding bedding material. On the other hand, in a case of a rigid pipe all the loads have to be resisted by the pipe. This simply means that in case of overloading, the flexible pipe simply deforms further whilst the rigid pipe fractures. Both flexible and rigid pipes require proper backfill, although the pipe/backfill interaction differs. In general terms, a flexible pipe offers significant structural benefits to the project designer. In many situations, a properly installed flexible pipe can be buried much deeper than a similarly installed rigid pipe because of the flexible pipe/backfill interaction. A rigid pipe is often stronger than the backfill material surrounding it, thus it must support earth loads well in excess of the prism load above the pipe.

Conversely, a flexible pipe is not as strong as the surrounding backfill: this mobilises the backfill envelope to carry the earth load. The flexible pipe/backfill interaction is so effective at maximising the structural characteristics of the pipe that it allows the pipe to be installed in very deep installations, many times exceeding allowable cover for rigid pipes when identically installed. The Weholite Pipe The Weholite pipe and the enveloping soil mass, working in tandem as a composite unit, is one of the most remarkably synergistic systems in engineering. When the soil is properly compacted around the pipe, the load-carrying capacity of the pipe-soil system far exceeds the individual capacity of either component by itself. In general, in the designing of polyethylene pipes, it is commonplace to assume that the overburden load applied to the pipe crown is equal to the weight of the soil column projecting above the pipe. Often, this is referred to as prism load. This prism load is a handy convection for calculating the earth pressure on the pipe when estimating vertical deflection, but the actual load transmitted to a pipe from the soil mass depends on the relative soil stiffness and pipe stiffness.

The dead load applied to a flexible pipe is considerably less than the prism load because soil-shear resistance transfers part of the soil loads that is directly above the pipe into trench sidewalls and embedment. This transfer is called arching and this term is usually used to imply reduction in vertical loads. The soil tries to follow the pipe downwards, but soil movement is restrained by shear resistance, along shear planes in the backfill soil, to be transferred in the adjacent soil. Therefore the amount of force exerted on the pipe by the backfill is less than the weight of the backfill soil mass, that is, less than the prism load.

Conclusion In summary, compared with rigid pipes, flexible pipes are versatile and have important structural performance advantages. Unlike rigid pipes, flexible pipes have excellent resistance to differential settlement. Plastic pipes, when overloaded will simply deform further to generate greater passive earth pressures, until the system regains equilibrium. In contrast, overloaded rigid pipes are subject to fracture that can result in catastrophic failure.

The comparison of the behavior between rigid and flexible pipes, demonstrates clearly that the flexibility can be characterised as a factor which increases the safety of a buried pipe and is not a disadvantage. The strength of flexibility in combination with the unique properties of Polyethylene makes Weholite an ideal product for water solutions. Box Out Section Asset International Ltd. has been instrumental in leading the debate on the use of HDPE over traditional materials and rather than just manufacturing and supplying the systems, takes responsibility for continually developing and testing the materials used. The process of assessing the long-term product benefits as well as improved performance and usability of the products, is a commitment the Company continues to make.

Asset is an active member of the British Plastics Federation’s Plastic Pipes Group. WEHOLITE is a WRc approved product and is manufactured in accordance with Pr EN 13 476 Standard Structured Wall Piping Systems of Polyethylene (PE) published by the European Committee for Standardisation. WEHOLITE pipe satisfies the requirements of a number of international standards and is also approved for the use in public water supplies across the UK.

High Density Staying Power

Thu, 17 Dec 2009 05:37:00 -0500

When new materials haven't been in existence long enough to demonstrate their longevity in the field, producers need to use other means to reassure specifiers about the design-life of the materials they choose for infrastructure solutions. Here plastics specialist Dr Vasilios Samaras explains how he can demonstrate the 100-year plus design life of high-density polyethylene.

Over the centuries mankind has worked hard to develop synthetic materials that offered benefits not found in natural products around him. The first ever synthetic plastic was cellulose nitrate, discovered in the middle of the 19th century. Plastics started to develop in earnest throughout the 1920s and were used extensively by the military during the Second World War.

Nowadays, plastics are found everywhere in society and are often used to replace traditional materials such as wood, stone or metal. Of all plastic materials, high-density polyethylene (HDPE) manifests the strongest growth in usage, especially in the pipe industry. In Europe alone, approximately 1.3 million tonnes of HDPE was processed into pipes last year. In general terms, HDPE pipes provide designers, developers and contractors with a reliable, durable and cost-effective solution for a wide range of applications including gas, municipal, industrial, storm water attenuation, mining, landfill and electrical and communications duct applications.

HDPE pipes are also effective for above-ground, trenchless, floating and marine installations. In addition to the operational advantages offered, there are many cost benefits, including low maintenance and ease of installation, compared to traditional materials. This combination of assets has made plastic pipe a very competitive product. A question often raised, especially by traditional pipe manufacturers, is: How can you prove the life-span of 100 years for HDPE pipes when they have only been in existence since the 1950s? One wonders why this should be raised at all, given that, in this age of green awareness, environmental experts quite confidently predict that plastic carrier bags won’t degrade for up to 300 years.

Whilst this may be held as an environmental negative in that case, within the arena of pipes, it becomes a positive. However, the longevity of HDPE pipes can be proven with scientific research, as the following will show. Only two years after Prof. Karl Ziegler, succeeded in polymerising ethylene in the presence of organo-metallic catalyst blends under mild pressure and temperature conditions, the first regular HDPE production plant, with a capacity of 200 tonnes per month, was already in service. For this discovery Karl Ziegler, together with the Italian chemist Giulio Natta, was awarded the Nobel Prize for Chemistry in 1963. It was the beginning of a very successful story - by 1962 the worldwide production of HDPE had already reached 200,000 tonnes. Today the quantity of HDPE produced worldwide every year is estimated at 35 million tonnes (2007; all polymerising processes). By 2010, this figure is predicted to rise further to 40 million tonnes of which approximately 4 million tonnes will be processed into pipes.

The first HDPE pipes had to compete against traditional materials that had been in existence for many years and, therefore had a track record with the water supply companies who needed pipe systems with a minimum service life of 50 years. As Ulrich Schulte states in his inspirational work: A vision becomes true – 50 years of pipe made of HDPE: Creep tests on HDPE pipes were begun as early as the middle of 1954. Dr. Kurt Richard, the then Head of the Materials Department at Hoechst, adapted to plastic the existing method of predicting the service life of high-temperature steels. He applied the Larson-Miller correlation to the stress characteristics of HDPE. In 1959, after only 4 ½ years of testing at 80 °C, extrapolation of the time-to-failure values already permitted a prediction of the service life of the tested pipes to be 50 years at 20 °C. Two pipe specimens installed in October 1956 are still undergoing creep tests at a temperature of 20 °C and under hoop stresses of 5 and 7.5 N/mm² respectively. On 18th October 2006, the extrapolations of the pioneers of pipe life prediction were finally and most impressively confirmed! The findings obtained in this concrete case of application are of fundamental importance, as the very same extrapolation method is used for predicting the service life of todays generation of HDPE pipe materials.

This work states that the minimum service life of HDPE is 50 years. The success of the global use of HDPE pipes led to a significant improvement of the calibration and extrusion equipment but most importantly to the improvement of HDPE pipe materials. The first HDPE pipes installed in Germany were made from the so called first generation material. Nowadays we are using fourth generation materials which, has resulted in considerable improvement in the design life. The following graph demonstrates clearly that the design life of pipes manufactured from high performance materials is well above 100 years. It is also important to emphasise the considerable development to the additives, like new types of carbon black, as well as the new generation of antioxidants which provide further improvement to the final quality of the pipe. Of course we should not neglect the fact that first generation HDPE pipes installed over 40 years ago are still in use without any signs of fatigue. Ulrich Schulte refers to an example of some first generation pipes which were installed in 1955 at Hoechst AG, a chemical company in Frankfurt am Main, in 1955.

The pipe system had been used for the supply of fresh water to an entire floor of the building. It could be assumed that the pipes had provided a continuous flow of oxygen-saturated water for over 40 years. Some of the pipes were removed from the building and subjected to tests in order to establish the residual life expectancy. The results were impressive concluding to a value of at least 28 years. This clearly shows that the pipes would have exceeded by far the expected service life of 50 years.

There is a wide range of articles referring to tests that evaluate the design life of HDPE pipes. Dr. Lars-Eric Janson has published a large number of these articles referring to tests made in HDPE pipes. In his tests, one pipe was compressed to 5% vertical deflection between parallel plates and held, in some cases for nine years. The stiffness regression recorded, directly relates to the relaxation of the modulus of elasticity. In another series of tests, pipe was deflected to 4.3% and 13.6% and held for eight years, with the same regression being recorded on a log scale. The regression curves can be projected to 100 years, which is slightly over one order of magnitude from the period tested. Furthermore, Dr. Janson found that tests conducted for as little as 100 hours were sufficient to make safe extrapolations up to 50 years or more for PE pipe.

As years pass we will encounter examples showing how HDPE pipe stands up to the tests of time. Meanwhile designers and specifiers can enjoy peace of mind in knowing that rigourous scientific testing demonstrates clearly that this material has the staying power of several generations. However, in retrospect, if the Romans had been given access to this durable, flexible solution over 2000 years ago, would they have in fact, favoured its more traditional counterpart, concrete?

Go with the Flow

Thu, 17 Dec 2009 05:37:00 -0500

During this summer’s exceptional rainfall the capabilities of the UK’s ageing water infrastructure to handle higher flow rates became an important factor determining the severity of the flooding which followed. Hydraulics - a subject often disregarded in the industry - plays a key role in ensuring effective water management. Research now demonstrates how plastic is hydraulically more efficient than concrete or clay piping.

These traditional materials are also more susceptible to blockages in extreme weather conditions, leading to requirements for high jetting pressures which subsequently incurs high operating and maintenance costs. Here leading plastic pipe expert Dr Vasillios Samaras outlines the importance of the hydraulics factor in ongoing plastic versus concrete and clay debate. Even by conservative estimates, flow capacity is 30% greater in a high density polyethylene (HDPE) pipe than in a comparably sized concrete pipe.

The reason is that HDPE pipes have a roughness coefficient (ks) of 0.03 in comparison with concrete which is 0.15. A simple comparison (see figure 1)_illustrates the significance of this difference. The above example demonstrates that the HDPE pipe has a 33 % greater capacity than the same diameter concrete pipe. An alternative way to look at this is that, in order to achieve the same flow rates as that of a concrete pipe, a smaller diameter HDPE pipe could be installed, at a shallower gradient. This in turn reduces installation time since smaller excavations are needed, providing subsequent environmental benefits, such as a reduction in the carbon footprint and less disruption to the local community.

This theory of HDPE pipes’ superior behaviour over those made of conventional materials has been supported by extensive independent testing in Poland and is clarified further by Dr William B Rauen of the world renowned Hydro-environmental Research Centre at Cardiff University. “The roughness coefficient (ks) characterises the vertical size, orientation, geometric arrangement and spacing of the roughness elements. Drainage pipes with rougher surfaces (i.e. with higher ks values) will typically have a lower flow capacity due to increased drag caused by the wall. This occurs as a consequence of the pattern of dynamic pressure distribution formed over the roughness elements, with energy-consuming local accelerations and decelerations of the flow. The flow capacity of drainage pipes can thus be maximised by using pipes with the smoothest possible surface finish.” In the so-called Darmstadt abrasion test (DIN v. 19534, part 2), samples of commonly used pipe materials were filled with a mixture of sand and water, and then subjected to a specified number of rocking cycles. The amount of abraded material was measured at regular intervals. The results as illustrated in the graph (Figure 2), clearly indicate that high density polyethylene has the highest abrasion resistance properties of all the common pipe materials.

A further look to the properties of HDPE reveals its high abrasion resistance Moreover, it is important to emphasise that few materials offer better overall chemical resistance to corrosive acids, bases and salts. In addition polyethylene is unaffected by bacteria, fungi or even aggressive naturally occurring soils. Even hydrogen sulphide, the scourge of concrete pipes has no affect on HDPE. Kamila Gornas, an environmental engineer from the University of Technology in Wroclaw, Poland stresses that another distinct advantage of PE is that it provides the lowest bio film formation potential of all the common water pipe materials in use today. Bio film is the natural habitat for bacteria in water systems and forms on any surface in contact with water.

You cannot necessarily see it, but surfaces feel slimy to the touch. The bacteria migrate from the bulk water to a surface in a low flow or stagnant areas of the system and attach by producing a slime layer. Dangerous pathogens like legionella, salmonella, camphyllobacter and even viruses, present as bacteriophage, can inhibit biofilms. One of the main disadvantages of bio film is that bacteria produce acids that will cause extensive corrosion to tanks and pipes. Biofilm growth can cause flow restrictions in pipes, increasing pumping costs and reducing system efficiency. Moreover the effluent produced can cause taint, taste and odour problems. Once installed, polyethylene pipe will not be affected by micro-organisms, such as those found in normal sewer and water systems since polyethylene is not a nutrient medium for bacteria. Furthermore, siltation does not occur in the way it does in other materials such as concrete and long-term flow characteristics therefore remain constant.

This in turn results in greater hydraulic efficiency, far less risk of blockages and ultimately far lower maintenance costs. In summary, designers specifying pipe materials, should balance any relatively small initial cost saving in using traditional materials such as concrete and clay against the superior performance of the plastic option and the rapid pay-back on operating and maintenance expenditure. Added to that is the greater peace of mind during the asset life, not only to the water company but also to the general public. Dr Vasilios Samaras PhD is Technical Engineer at water management specialist company, Asset International Limited, based in Newport, south east Wales.

Plastic Solutions Provider is First Choice for £150 Million Wastewater Treatment Project

Thu, 17 Dec 2009 05:35:00 -0500

One of the UK’s largest water and wastewater treatment works has chosen a pioneering alternative for its water pipe systems,that will help improve the water infrastructure to over 1.8 million homes in the West Midlands. Severn Trent Water’s £150 million Minworth wastewater treatment works, near Birmingham, which is the second largest in the UK, has selected leading water management solutions provider, Asset International Ltd (Asset), to provide more than two miles of pipe for the multi-phase project.

The site is due for completion in May 2010. Contractors Bi Water, in partnership with BNMAlliance, have opted to use Weholite, the high density polyethylene (HDPE) pipe manufactured by Asset, instead of more traditional materials such as concrete or ductile iron. The large-scale project will use 1.65 metre diameter pipes to carry water in steep vertical drops of up to five metres and 6x9 mm diameter pipes for carrying waste from the massive distribution chambers.

At times the pipes will carry up to five million litres of water per second from the distribution chambers. Aside from traditional piping formats, Weholite has also been used in additional parts of the project. Bi Water required a lightweight and easy to install material for manholes and as Weholite pipes are made to order and prefabricated, they were quickly and simply placed, reaching depths of up to five metres underground. The expansive project often has as many as 400 workers on site at any one time so an astute health and safety policy is crucial.

As the Weholite pipe can reach heights of up to 2.8 metres, Asset, working with Bi Water, ensured the pipes were delivered in strict stacking heights providing easy and safe access for offloading the pipe from delivery lorries. Pat Heffernan, Bi Water site manager, said: “Because Weholite is both lightweight and flexible it’s helped remove a number of health and safety issues. The pipes are easier to handle and because they are prefabricated, they arrive ready to use, giving us quick and easy access to the chambers”. Mark Lee, project manager at Minworth for BNMAlliance agreed: “The manual handling of the pipes is much easier as plastic is lightweight and therefore much quicker to handle. This means there is a reduced risk of accident, which really helps our health and safety measures”.

The pipes have also proved highly ductile, easily managed on site as slots are simply inserted into the plastic for quick placement. Paul Fisher, Project Manager at Minworth for Severn Trent Water said “The project is the UK’s largest in terms of land scale and with hundreds of men on site, Asset’s quick delivery and ease of installation helps keep our project costs down”. Simon Thomas, managing director at Asset International added: “We continually strive to offer a versatile service for all our orders. Our pipes are made to order and coupled with a rapid manufacture time we offer a number of benefits to projects that require a quick turn around on materials”. “As Weholite allows for swift installation, another advantage is the significant time and cost savings, especially when compared with other traditional materials”.

Carbon Black

Thu, 17 Dec 2009 05:35:00 -0500

As green issues continue to rise up the political agenda, the water industry is being forced to look towards more innovative solutions that play a part in reducing carbon footprints. Plastics specialist, Dr Vasilios Samaras, examines how a material traditionally thought of as being detrimental to the environment is now proving to be the ‘greener’ option.

In an era where global warming is having a significant effect on our climate and catastrophic weather events are devastating local communities, the use of innovation is of vital importance. Historically, the use of traditional materials within the water industry has not only propagated hydraulic inefficiencies but also paid negligible attention to the environment.

Independent research has demonstrated that the use of plastic pipes, contrary to traditional beliefs, sets the foundation that could position the water industry at the cutting edge of the environmental agenda. When you consider that even a small construction site can produce approximately 0.8 tonnes of CO2 per week we begin to understand the importance of looking at the whole picture rather than identifying the areas of least pollution.

The main challenge at the moment is to analyse the carbon footprint in every project and then try to reduce it as much as possible without infringing too much on budget constraints. High-density polyethylene (HDPE) pipes have witnessed a strong growth in usage, particularly within the water industry, and research suggests they can contribute significantly towards the green objective. This will become more evident in the future as the water and construction industries begin the systematic evaluation of the carbon footprint for every individual scheme. Delivery is one of the major areas in which the advantage of plastic pipes becomes apparent and is supported by the use of a simple carbon footprint calculator endorsed by the Environment Agency. For example, considering the CO2 emissions on the delivery of 14 metres of 2.1 metre diameter HDPE pipe (which would be delivered on one vehicle) compared to the equivalent length of concrete pipe, which would have to be delivered over a number of vehicles, it is clear that the CO2 emissions of the plastic is just a fraction of the concrete. This is before we even take into consideration the installation time and plant requirements.

This can be represented graphically as follows: (see figure1). Due to the different mixtures and production methods for concrete pipes three different values have been used to demonstrate the best and worst case scenario. Even in the best case scenario for concrete pipes, the CO2 emissions are 50 per cent higher than the HDPE equivalent. It is also important to emphasise that there is a considerable increase in CO2 footprint of concrete pipes the further they travel from their manufacturing base due to their heavy weight. Of course, this is still a simple calculation, however water authorities across the UK and the private consulting engineers attached to the AMP 4 programme are providing more extensive independent research that adds conclusive evidence to the debate. While the level of the results varies from project to project in every case, the outcome is firmly in favour of plastic.

On one particular flood alleviation project carried out by Asset in the last few months it was calculated that the carbon footprint of the large diameter plastic pipe was only 15 per cent of the concrete equivalent. These statistics contradict research carried out a few years ago that was endorsed by the Department of Trade and Industry that concluded concrete pipes used in gravity sewers were environmentally sound. The work omitted vital carbon contributing factors such as speed of installation, a reduction in plant requirements and one of the major offenders, transport to site. Figure 2 clearly illustrates the advantages of transporting plastic pipes with reference to the carbon footprint. In figure 2, 140 metres of pipes are nested inside one another and are delivered to site in a single load.

Figure 3 shows a massive pre-fabricated section of a 300m3 CSO attenuation tank with a weight of less than five tonnes that was manufactured offsite, delivered and installed in just a few hours. To construct this on site using traditional methods would have taken at least eight weeks. The 300m3 CSO attenuation tank consisting of 3000mm diameter pipes and prefabricated sections which is illustrated in Figure 3 was installed in a very populated area. The tank was placed in the open trench in less than five hours and the total installation including excavation of the trench and back-fill took only few days. This dramatically reduced the environmental impact not only through the CO2 emissions but also through something which is almost impossible to measure, the effects of such a large scale construction on the local community (see figure 4).

The Government has set a challenging target to reduce the UK’s carbon footprint by up to 60 per cent by 2050 and it is therefore essential that the construction and water industries synchronise their efforts to ensure a significant reduction in CO2. As the years pass we will encounter examples showing how HDPE pipes stand up to the environmental test against its competitors. Meanwhile designers and specifiers can feel confident that they are working towards a greener agenda. Dr Vasilios Samaras is technical engineer at water management specialist, Asset International Limited.

Plastic Solutions Provider Selected For Innovative Hydro Power Project

Thu, 17 Dec 2009 05:33:00 -0500

A pioneering hydro-power scheme has chosen leading water management solutions provider, Asset International Ltd (Asset), to provide the water transportation pipes at their pro-environment energy production project at Glendoe, near Loch Ness. The scheme, which is owned and operated by Scottish and Southern Energy (SSE) working with Hochtief Construction AG as the main contractor and subcontractor Highlands Quality Contractor (HQC), is the largest civil engineering project in Scotland and is using the high density polyethylene (HDPE) pipe manufactured by Asset, in their aqueduct system for transporting vast amounts of surface water to a reservoir in the Glendoe hills.

The Weholite pipe will help transport the water from an area of over 75sq kilometers, at what is the first large-scale conventional hydro electric station to be built in Scotland for almost 50 years. The station is already generating enough electricity to power every home in a city the size of Glasgow. The water is collected in a reservoir above the power station, where annual rainfall is approximately 2000mm. As the Weholite pipe is high density polyethelyne, it is the ideal choice for an area such as Glendoe where temperatures can reach 25 degrees below zero, it doesn’t become brittle as it adjusts to extreme temperatures.

Weholite pipes are also much lighter than concrete and ductile iron pipes, meaning they can be transported up the mountain easily and quickly. Dennis Kearney, director of HQC, said: “Given the demanding conditions we had to work with, Weholite pipe was the best product for the job. We have 9,500 km of the pipe running in hills 2500 metres high, it was imperative that we selected a lightweight and durable pipe”. Asset also managed to redesign transport costs for the project by helping to reduce the pipeline to include a 50/50 split between 2m and 1.8m pipes, so the loads could be nested and transported together.

Julius Wallace, Glendoe site manager for Hochtief Construction AG, said: “Asset provided many cost-reducing benefits; as the HDPE pipe comes in longer lengths than alternative products, we saved time and money during the joining process. “The HDPE pipe is more flexible, with standing larger grading envelopes for bedding and back-filling material and is less brittle for transportation and installation than the fibre-glass GRP pipe traditionally used for projects like this. We haven’t needed to cover costs for specialist bedding material as we were able to use self-compacting rock that can be processed on site.” The power station began creating power in December 2008 and work is now ongoing to reconstruct the surrounding landscape.

Neil Sandilands, project manager at Scottish and Southern Energy said: “Because the pipes are lightweight they’ve been easily transported up the steep inclines and then easily manoeuvred into place on the mountain-side. We also reduced our health and safety worries thanks to the speed and ease with which the pipes can be handled. “The fact that Asset managed to save our costs while also reducing carbon emissions means they were the right choice for such an eco-friendly scheme”. Landscaping and final reinstatement will be complete in June 2009, meaning the pipes and other equipment will not be visible from any buildings or roadsides.

Simon Thomas, managing director at Asset, said: "We are delighted that Weholite has featured so prominently in such an innovative and eco-friendly project like Glendoe. As a company we have a strict environmental policy and relish the opportunity to be involved in sustainable schemes. Our efforts to reduce loads and the fact that Weholite is manufactured in the UK means it’s a much more carbon friendly choice than other traditional products". “As Weholite allows for swift installation, an additional cost benefit is the significant time savings, especially when compared with other traditional materials”.

World’s largest plastic pipe rolls off production line at Asset International

Mon, 17 Aug 2009 15:35:00 -0400

Leading water management solutions provider, Asset International Ltd, has opened a new production line at its factory in south Wales. The £2 million investment in the state-of-the-art production line and fabrication bay will enable Asset to produce a 3.5m diameter plastic pipe, the first of this size to be produced. The new pipe, which is the world’s largest high-density polyethelyne pipe, provides large-scale solutions for customers looking for easy to install, flexible pipes that mirror the strength of traditional materials.

Asset, which is part of UK-based infrastructure, building and construction products group Hill & Smith Holdings Plc, is now in its 12th year of trading, and with a turnover of more than £10 million, is experiencing increasing demand for its high-density polyethelyne (HDPE) pipe systems known as Weholite. Simon Thomas, managing director at Asset, said: “The new facilities will allow us to double our output capacity and provide our customers with an increasingly wider range of solutions.” “We’ve already secured several forward orders for the new size pipe and are experiencing a great deal of interest from potential customers who would usually use more traditional materials but are now realising the benefits of Weholite. “The new 3.5m diameter pipe will offer further opportunities for the use of the pipes including in pre-fabricated SUDS solutions in-line with the Government’s future water strategy for flood alleviation in England and Wales.

From one extreme to the other

Mon, 17 Aug 2009 15:35:00 -0400

High density polyethylene pipes (HDPE) are now common place for a variety of purposes and are increasingly being used as a replacement to more traditional materials, such as concrete or iron, thanks to its reliable, long lasting and durable properties. Dr Vasillios Samaras, senior technical engineer at HDPE pipe manufacturer Asset International looks at how the pipe is increasingly being used for projects that subject it to extreme conditions and how the material is able to cope with the most severe forces that Mother Nature can throw at it.

While it is accepted that plastic pipes provide a cost-effective solution for a range of piping applications, HDPE pipe is increasingly being used for a wide variety of purposes in more extreme environments. The last three decades have seen a significant increase in the use of plastic pipes in innovative engineering solutions such as marine applications, and hydro-projects where temperatures can plummet to extreme lows. HDPE pipe is the top choice for the growing number of marine applications that require pipelines installed on the sea-bed. Treated ductile iron or concrete pipes do not offer anywhere near the excellent level resistance to abrasion, corrosion and chemicals that HDPE proffers. As a result, the cost does not to need to incorporate extras such as surface coatings or other additional preparations.

Rigid pipe materials are susceptible to cracking or breaking completely; whereas HDPE pipe has a natural ability to flex, which enables it to adjust to different loading conditions, vibrations, stresses and movements without causing any damage to the pipe system while under water. Flexible pipes are extremely versatile when compared with rigid pipes, and have important structural performance advantages. Unlike rigid pipes, flexible pipes have excellent resistance to differential settlements. When overloaded, the structured-wall pipe will simply deform further to generate greater passive pressures until the system regains equilibrium. Solid-wall polyethylene pipes reach sizes of up to 1.6 m in diameter and have already been installed in several projects throughout the UK but the need for larger sizes is growing. Structured-wall polyethylene pipes carry every benefit associated with their older sister, the solid-wall polyethylene pipe, in the marine field. And now plastic pipe manufacturers are able to use high quality structured-wall technology that can reach size of up to 3.5 m diameter. Larger pipe sizes generally have a decreasing ability to cater for settlements and uneven seabeds.

In this respect, structured-wall pipes have an advantage because their pipe wall design will more readily adjust itself. The pipe not only has to prove strong and durable once installed, it needs to withstand several testing demands during the sinking process. Throughout sinking, the pipe is subjected to stresses much higher than those experienced during its actual use. A large bending radius capability is needed to allow for the ideal smooth ‘S-bend’ sinking operation. For pipes with a large diameter, the pulling force needed to uphold the bending radius can be extremely high, so a good bending radius capability is crucial. As plastic pipes can be submerged using open ends, the force on the pipe system during sinking is significantly decreased. The smooth and controlled ‘S-bend’ sinking operation is further enabled by the natural buoyancy of plastic pipes and the bending radius capability of 50 times the outside diameter. It is also crucial that the pipe must not be over-stressed or moved on the seabed, so a suitable weighting system is required. Thanks to the flexibility of structured wall pipe, it corrects itself following any influence from weighting.

As a high-quality structured wall system, this product has proven itself in several marine installations both for water intake lines, cooling water systems and sewage out-falls. It is also worth noting that an additional benefit of structured-wall pipe for marine applications is the significant time and cost savings procured during installation. Long piping sections can be prepared and welded on land before sinking, saving manpower once the pipe has been laid. As plastic pipes are laid during using the simple “float and sink method” minimum equipment, boat and manpower is required, providing further cost and time savings.

The Longman Out-fall in Inverness installed in 1998, is a prime example of such product versatility thanks to the decision to use structured wall pipe for a sea out-fall. 500 metres of 1.65m pipe was installed in 100 metre strings, saving the client installation time and considerable costs. The lower carbon footprint of HDPE (which can be up to 85% less than concrete) is also an attractive prospect for many end-users keen to meet green initiatives, especially for transatlantic projects. As the pipe is lightweight and can be easily nested, the reduction in deliveries significantly reduces carbon emissions during transportation. Asset International regularly delivers fully nested loads to the Falklands Government providing dramatic reductions in delivery costs and carbon emissions.

The HDPE is used in water transportation applications in the Falklands where temperatures can plummet well below freezing, especially in marine environments. HDPE is an ideal choice as steep variations in temperature will not affect the pipe’s structure, unlike concrete and ductile iron pipes which are highly susceptible to cracking or damaging in extreme cold. HDPE pipe is also used for projects closer to home that expose water transportation pipes to sharp fluctuations in temperature. A pioneering hydro-power scheme in Glendoe, near Loch Ness has recently used HDPE pipe for transporting vast amounts of water from a reservoir high up in the Glendoe hills down to a power station, covering an area of 15 sq kilometres. Once again the lightweight nature of the pipe meant installation and transportation up the steep mountain-side was quick and easy, saving time and costs. Additionally, it was the ideal choice for an area such as Glendoe where temperatures can reach similar extremes as experienced in the Falklands.

What distinguishes HDPE from its rivals is the diversity of applications for which the pipe is ideal. While HDPE pipe has proven itself in a number of applications, the cost of delivery and speed of installation places it high above traditional pipe materials. Furthermore, its prominent role in green applications and its lower carbon footprint means HDPE pipe is a highly competitive product and looks set to remain so. Dr Vasilios Samaras is technical engineer at water management specialist, Asset International Limited.

Solution Plugs Flooding Issue in Norfolk

Mon, 17 Aug 2009 15:33:00 -0400

An innovative water management solution has become the product of choice in a project designed to reduce the risk of flooding to a residential area in Norfolk. The £340k project in Cromer is the second flood alleviation scheme - delivered by Barhale Construction on behalf of Anglian Water Services - to involve the use of Weholite - a high-density polyethylene (HDPE) pipe manufactured by Asset international Ltd. Part of the Anglian Water AMP4 investment programme, Asset’s solution is designed to attenuate and control the excess flow of storm water running down to the residential area of Barclay Close from a commercial park/centre situated above on raised land.

Weholite became the product of choice after Anglian Water Services utilised the product in a similar project in March 2007, which subsequently gained recognition as runner up at the Chartered Institution of Water and Environmental Management (CIWEM) AGM in May 2007 David Chadwick, sub programme delivery manager of the Anglian Water @ One Alliance, commented: “Flood alleviation is high on the agenda of our customers and we are eager to develop more efficient solutions such as Weholite pipes as part of our major investment programme in this area. “Asset’s bespoke product provided the ideal solution for both flood alleviation schemes in Cromer. In addition to reducing our project time-frame, we gained an estimated 30% cost saving overall”.

Working in partnership with the flooding sub programme design team of The@One Alliance - a collaborative organisation formed to deliver the AMP4 programme - Asset was commissioned to design a bespoke off-line storage tank with flow control devices The solution consisted of two 2,100mm diameter Weholite tanks which will contain water diverted from an existing manhole via a new sewer, and will have a capacity of 480m3 of water when full. During periods of heavy rain, water will be stored in the tank and released by gravity at a controlled rate through a 40 ltr/sec Hydroslide valve, when the storm abates. For this specific project, it was estimated that the volume of trucks required to deliver and off-load the materials would be reduced from 50 to eight by using Weholite, proving less disruptive to the surrounding environment and residential area during construction. Disturbance to the community was also significantly reduced as one lane of the neighbouring road remained open throughout the project. The amount of land available for the project restricted use of materials and solutions extensively.

The Weholite tank requiring only 315m², provided a tangible solution for various reasons, as Andy Pearce of Barhale Construction, explained: “The tank provided significant labour, installation time and cost savings, with an estimated three-fold reduction compared with traditional materials such as pre-cast concrete. “Health and safety was also a key factor. The product pre-fabricated and then joined on-site, decreased the amount of time workers spent in the trenches and in confined spaces”. Simon Thomas, managing director of Asset, based in Newport, South Wales, commented on the benefits of utilising Weholite, compared with traditional materials such as concrete. He said: “Our product is significantly lighter than other materials, providing benefits to the water company in terms of time and cost savings, and to the contractor during transportation and installation of the pipes. “By working in partnership with water companies such as Anglian Water Services, we aim to provide durable and sustainable solutions to water infrastructure issues across the UK. Our increasing partnerships with water companies and flood alleviation schemes is testament to the strength and reliability of the Weholite product”.

Pioneering pipe system awarded patent

Fri, 14 Aug 2009 11:38:00 -0400

Leading water management solutions provider, Asset International Ltd, has been awarded a patent for an innovative combined sewer overflow (CSO) solution that will cut on-site construction costs of CSO chambers by at least 30%.

South-Wales based Asset has received the patent rights for their LiteSpeed chamber which prevents the discharge of foul water into surface water drainage systems. Asset worked in conjunction with Morrison Construction Services Ltd and Hyder Consulting to develop the chamber, which is designed to answer CSO engineering requirements.

The LiteSpeed patent will benefit many flood alleviation projects, included in the Asset Management Programme (AMP 4/5), thanks to the flexibility, efficiency and savings in time and cost of the product. As LiteSpeed is manufactured using Asset’s high density polyethylene (HDPE) pipe, known as Weholite, it is lightweight and can be delivered in any length satisfying specific and bespoke designs. The lightweight nature of the product dramatically reduces its installation time not only resulting in a lower health and safety risk for onsite personnel, the reduction in onsite installation means minimal disruption to local communities and the environment.

Simon Thomas, managing director at Asset International Ltd said: “Asset can manufacture and deliver the CSO chambers rapidly and to exact specifications. The use of Weholite lends itself to bespoke engineering designs therefore reducing the need for in situ build solutions that have long programme times. The quick manufacture and delivery time of the factory-built LiteSpeed means projects will see direct results in time and cost savings and an improvement in quality.” The environmentally friendly solution requires one delivery to site and thanks to its minimal waste and rapid installation it provides greater energy savings than other traditional materials such as concrete or GRP.

LiteSpeed also comes with a 120 year design life, excelling previous durations by forty years. Mr Thomas added: “We’re excited to be the only HDPE solutions provider in the UK that can offer such an innovative system, enabling us to offer significant cost savings and reductions in design and installation time for our customers.”

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Sat, 17 Jan 2009 05:46:00 -0500

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