A Guide to the Selection of Jointing Methods for Polyethylene Pressure Pipes
In the trench we face different situations, conditions, or tasks that can be managed in different ways. At times we want to install a new pipe, while in others we just want to repair an existing one. However, we have to bear in mind that not all pipes have the same characteristics and that the available space to work on the trench is usually limited. Therefore, there is always a jointing technique that will be more appropriate or will make the installation easier.
A Good Practice Guide for Flange Jointing of Polyethylene Pressure Pipes
Flanged joints are normally used to connect PE pressure pipelines to valves, pumping stations and pipelines of other pipe materials. A flanged joint to be used for PE pipes consists of different components, might be manufactured by different companies. The joint must be able to transfer long-term axial forces with maintained tightness, which requires use of suitable components and a correct assembly.
Read more: TEPPFA Technical Guidance Document - AGU201402
A Good Practice Guide for the Electrofusion Jointing of Larger Diameter Polyethylene Pressure Pipes
Polyethylene piping systems are being increasingly accepted in larger diameters (above 315 mm) as a result of their proven performance advantages and the cost elective installation techniques which can be employed.
Electrofusion (EF) is an important and reliable jointing method for polyethylene pipes and a wide range of EF fittings approved to EN 12201-3/ EN 1555-3 are ordered in the market.
Usually EF training and certification is only applied to smaller dimensions, the common influencing factors for good installation practices and the preventive measures to avoid welding failures are often not understood.
Read more: TEPPFA Technical Guidance Document - AGU/2014/01
One of the tests in European approval procedures involves the test for Taste & Odour. It is the first and basic requirement for the approval of materials for drinking water application. This means that all legally approved materials for drinking water application in the market have met the stringent requirements of this test.
Many countries are using a so-called "Positive List" (PL) where all chemical substances used in the plastic piping system are listed. Clearly there is an interest to ensure that substances that could migrate into the drinking water do not cause harm to human health. These tests ensure that defined limit values are not exceeded and that these PL limits are established with very high safety factors.
Suppliers of materials for drinking water distribution, have to meet these strict requirements. So legally approved plastic materials for drinking water application are classified as not harming human health with respect to listed substances of the Positive List. In several EU countries, various tests are used to secure the highest quality level regarding the potential migration of substances into the drinking water.
The conclusions from long term experience in use and from the application of modern analytical techniques are clear. Plastic pipes that have been legally approved do not negatively affect the quality of drinking water. Moreover, they contribute significantly to its safe supply for human consumption.
Read more: Plastic Pipes do not Contaminate Drinking Water
Design of Buried Plastics Pipe Systems
In 1999, a key technical study was concluded regarding the design of thermoplastic pipe systems. This project resulted in a much better understanding of the flexible behaviour of plastic pipes and their installation aspects. A design graph was developed, predicting the deflection of pipes in practice.
Sponsored by TEPPFA and PlasticsEurope, the project team consulted a wide range of industry experts from across the sector. Leading professors throughout Europe were given the possibility to check their calculations for pipe installation. A steering committee from industry was also set up to oversee and support the work in whatever shape and whatever form that was needed.
Read more: Abstract, Design Parameters
Expected Lifetime of Plastic Pipes
Several significant studies regarding the predicted lifetime of plastic pipes have been carried out. A report published in The Netherlands officially confirmed in 2006 that the life span of existing PVC pipes when installed according to the correct conditions is more than 100 years. A similar study has been published regarding the durability of PE pipes and there are other technical references.
Read more: Lifetime of PVC pipes 1, Lifetime of PVC pipes 2, Lifetime of PVC pipes 3,Lifetime of PE pipes 1, Lifetime of PE pipes 2
Energy Consumption – GUA Study
A comprehensive study carried out by PlasticsEurope and GUA, an Austrian environmental consultancy has important implications for the use of plastic products and hence plastic pipe systems. The study found that substituting plastics where possible by more traditional materials throughout Western Europe would require additional energy equivalent to 22.4 million tons of crude oil. The result in additional greenhouse gas emissions would be 97 million tons, equivalent to 30% of the EU-15 Kyoto target for the period 2000 – 2012.
Read more: GUA Summary, GUA Full Study
Life Cycle Assessment Studies of Pipes
The Vienna Institute of Environmental Management compared different pipe materials used for water supply and sewer applications. More commonly known as the Windsperger Study, this critical study published in 1999 examined the various aspects of Life Cycle Assessment as applied to plastic pipes and comparative materials. Its conclusion that “no distinct inferiority against other materials can be justified with existing LCA-studies” is fundamental in terms of the environmental contribution provided by plastic pipe systems.
Read more: Windsperger Study