Case Studies from Around the World
Plastic Pipes Conference Association # 2004 Milan
Alessandro Soresina, David Walton
AEM S.p.A. is the leading Italian company in the management of public utility services, based in Northern Italy (Milan), and operates in the sectors of electricity, gas and heat, telecommunications and other services which include both public and aesthetic lighting.
The parent company, AEM S.p.A.
have been listed on the Italian Stock Exchange since 1998.
With regard to gas distribution in Milan and the surrounding areas this is managed by Aem Gas S.p.A.
(the Gas Distribution company owned by AEM). The network supplies 860,000 customers with almost 1.2 billion cubic meters of gas each year.
In Milan the gas distribution activity started around 1870, with the first gas distribution network providing public lighting for the city. Later on the network was used to supply gas to domestic customers for cooking, water heating and so on.
This early gas (town gas) was produced from coal, and this kind of production lasted for more than one century. The conversion of the gas distribution system from town gas to natural gas took place between 1984 and 1994.
Fig.1. Structure of AEM S.p.A.
The development from this town gas system meant that the current gas distribution network is characterised by:
- Large low pressure network (working at 15x10-3 bar for town gas)
- Many large diameter mains (from 2 inch to 40 inch in diameter)
- “Traditional” mains materials (grey cast iron, ductile iron, steel)
In the 1990’s Aem Gas started a major replacement program of the gas distribution network in order to reduce maintenance costs and improve the networks efficiency and safety. Aem Gas used a variety of pipe lining technologies in order to satisfy the different external constraints connected to this activity. Apart from open trench burial different no-dig technologies have been adopted, such as:
- Slip lining with the accompanying pipeline diameter reduction.
- Close-fit relining with a minimum reduction in diameter.
- Pipe replacement without size reduction or “up-sizing” using “Pipe bursting”.
Polyethylene has been chosen for the renovation or replacement of all low pressure (LP) mains up to 315 mm in diameter. For medium pressure (MP) pipelines steel continued to be used because it was fully compatible with the existing system and the installation technology was well understood.
Related papers
Author(s) : Bruce Mowry, PhD, P.E., Brian Dorwart, P.G., P.E., David Mancini, Bryan Fletcher, Roger Williams, P.E., Rene Brito, EIT, Arnelio Alfonso, P.E .
The City of Miami Beach owns and operates a 54-inch sanitary sewage PCCP force main (FM) that was built in 1977. This FM is the only transmission pipeline for conveying about 22 million gallons per day (MGD) of raw sewage to the wastewater treatment plant. In 2012, the City identified structural deficiencies in the...
Author(s) : Patrick Campbell, Joanne Claronino, Shana Meeus, Joseph Sanders, David Chrystie-Lowe
Polyethylene (PE) potable water mains, with design life of 50 years (BS EN 12201), have been in widespread use in the UK water industry for more than 30 years. PE pipe is light, flexible and reliable in comparison with other pipe materials and the UK water industry has made a considerable investment in replacing...
Author(s) : Vivek Rohatg, Gregor Hiesgen, Mark J. Lamborn, Ashish M. Sukhadia, Douglas E. Simpson, David W. Borrego, Pamela L. Maeger
Maintaining dimensions within specifications is problematic for the extrusion of large diameter thick-wall polyethylene (PE) pipe (> 75 mm wall) due to sag caused by insufficient resin melt strength. However, sag can be controlled through careful resin selection and optimization of the pipe cooling process. This...
Author(s) : Isabelle J. Berger, Andreas Frank, Gerald Pinter, David Nitsche, Dirk Petry
Electrofusion (EF) sockets constitute a well-established and practically proven technology for the joining of polyethylene (PE) pressure pipes. As for the pipes, the potential lifetime of such welding connections is beside other properties also depending on the resistance against slow crack growth (SCG). The current...
Author(s) : Mario Berna, Alessandro Tinarelli
PVC pipes and fittings are currently manufactured using a wide range of stabilizer systems whilst CPVC is currently manufactured using Tin stabilizers. The aim of this paper is to present a new type of heat stabilizer (booster) to be used in combination with Tin stabilizer; surprisingly this product offers...
Author(s) : Lonnie Corley, Dane Chang, Harvey Svetlik, Matt Brandes, Thomas Musto, Frank Schaaf, David Fink
This paper presents a brief overview of a challenging project at the Callaway Nuclear Power Plant where HDPE was utilized to replace degraded steel buried piping in a Safety Related water system. Callaway was the first Nuclear Power plant to obtain NRC approval and successfully place the HDPE piping system into...
Author(s) : Ian Aldridge, Declan Robinson, Dave Smart, Chris Reed, Martyn, Greig, Trevor Stafford, David Christie-Lowe, Alec Erskine
For the UK polyethylene (PE) gas pipe network, the first installations now exceed 40 years in the ground, with an original design life of 50 years. It was thus timely to review the current condition and performance history of these first generation PE materials. A major 4 year project was started in 2010 to examine...
Author(s) : David Chrystie-Lowe
The many benefits of PE100 pipe materials include flexibility and toughness in addition to being relatively light products that are not subject to corrosion and expected to last well beyond the design lifetime [1]. It is also a distinct advantage that end-load resistant joints can be made using butt fusion (BF) and...
Author(s) : Nick Mark, Eric Bridgstock, David Carey
An insight into a unique approach to the management of electrofusion and butt fusion joint quality on polyethylene pipelines. The presentation will reference experience and learnings from a system that has already been used in the field to great effect (see Abstract) and a new approach to butt fusion (see enclosed...
Author(s) : Mario Berna, Alessandro Tinarelli
The PVC pipes are currently manufactured using a wide range of stabilizer systems. European market was historically based on Lead stabilizers that have been entirely replaced by COS (Organic-based and/or Calcium-Zinc) systems thanks to the Voluntary Commitment of the European Stabilizer Producers Association within...
Author(s) : David Becerril García, Jacinto Cortés-Pérez, Ian D. Moore
Joint performance of joints in gravity flow buried pipelines is very important since joint failure could produce structural or service limits to the system. Standards have been developed to evaluate that joints have the necessary structural and leakage capacities which specify test methods that are not clear and do...
Author(s) : Dr. Amaia Bastero, David López Piquer
The industrial sector has traditionally used metal pipes for transporting a wide variety of chemicals and highly corrosive liquids. When metal pipes are exposed to aggressive media, their lifetime is considerably reduced. Polyethylene pipes, have demonstrated since the 1950s to be a safe, reliable and cost effective...
Author(s) : Sonya Pemberton, David Chrystie-Lowe, Sabah Rafiq, Karolina Modelska, Edward Ingham
A room temperature tensile test using thin films taken from the outside and inside surface of polymer pipes has been developed to study the slow crack growth resistance of ageing PE pipelines via analysis of their strain hardening behaviour. A range of PE materials in service since the early 1970s and 80s are...
Author(s) : Márton Bredács, Andreas Frank, David Nitsche, Andreas Riha, Gerald Pinter
Within this paper the property and lifetime profile of four small diameter PE water pipes for house supply, which were installed between 1968 and 1992 in Vienna and Graz, Austria, were studied. Based on thermo analytical and structure analytical test methods the materials show still expected values for PE even after...
Author(s) : Dr. Dane Chang, Dr. David Marshall, Chris Cox
Plastic pipe applications often require polymers to have adequate abrasion resistance during usage. Although typical polyethylene resins have reasonably good resistance to abrasion and can be broadly used with a variety of chemicals, there are some demanding applications that require a resin with enhanced abrasion...
Author(s) : Alessandro Marangoni
keywords : water, total cost of ownership, installation costs, Italy, Germany This paper is based on a research done on behalf of ECVM by Althesys Strategic Consultants about the competitiveness of some PVC products (window profiles, pipes, flooring) applying the Total Cost of Ownership (TCO) methodology. The TCO...
Author(s) : David Hill Jean Carmier
A multilayer pipe named Excel Plus® made with a protective inner layer in PVDF was developed by GPS PE Pipe Systems, an Aliaxis group subsidiary. In order to assess, in accelerated mode, the resistance of this pipe against chlorine dioxide, a test sample exposure facility was built at the Aliaxis corporate R&D centre....
Author(s) : Cornati Alessandro
In April 2009, a major Earthquake hit the central region of Italy and the historical city of L’Aquila, provoking severe human damages and destruction of many building in the region.The gas distribution system was also affected, and evaluation of the damages organised by Enel Rete Gas, the operator of the system,...
Author(s) : Jane Toogood, Dorothea Wiplinger, Christophe Salles, David Walton
Securing access to safe water and sanitation is recognised as one of the world’s most pressing societal and environmental challenges. Launched in 2007 by Borealis and Borouge,‘Water for the World’ is a programme platform to advance solutions, expertise and know-how to address this challenge. Activities are grouped in...
Author(s) : Ken Murphy, David Lowe
Exova is continuing in the long tradition of Pipeline Developments Limited (PDL) in the UK with research, development, testing, quality assurance (QA) and failure analysis of modern plastic pipe materials and joints. Along with this ongoing work Exova has assessed various non destructive testing (NDT) techniques in...
Members of the Association
