Plastic Pipes Conference Association # 1998 Gothenburg
Ifwarson, Andersson
This paper presents experimental data for PEX, PEM, PP and PVC pipes exposed to different chemicals. More than 150 plastic pipes of PEX, PEM, PP and PVC have been pressure tested with different chemicals. The chemicals used are; 97% Sulfuric acid, 100% Acetic acid, 30% Sodium hydroxide and a solution of 50% Trimethylbensene and 50% n-Decan. The results are compared with hydrostatic pressure tests in water. Extrapolation using Arrhenius are discussed and demonstrated. Discussions about the failure mechanisms are presented illustrated by fractography. Based on the results a description of a new testing procedure to investigate the chemical resistance for plastic pipes is also presented.
Related papers
Author(s) : Sverre Tragethon, Martin Andersson
Global mega trends push for investments in sewage treatment capacity & efficiency. A trend is to go for central regional treatment sites, typically remotely located from dense populated cities. This calls for high capacity pressure sewage transmission pipelines. Reliable operation is of course of paramount importance...
Author(s) : Lars Jacobsson, Hans Andersson and Linda Karlsson
Problems sometimes occur in tightness testing of plastic pipelines using pressurized water and accounting for the diametrical expansion, particularly so for larger sizes and higher pressure rating. Pipelines that are in fact tight enough for acceptance are rejected when first tested. A study consisting of two parts...
Author(s) : Lars Jacobsson, Hans Andersson, Daniel Vennetti and Sven-Erik Sällberg
Leakages are reported in flange joints of large pipelines for water supply although mounted according to recommended practise. FEM analyses and full scale experiments have been performed in order to better understand the functioning of the joints. The objectives were to find out about the sensitivity to mounting and...
Author(s) : Lars Selling and Ingrid Andersson, Christophe Salles and Lars Höjer
Kungsors Plast AB, in co-operation with Borealis, has pioneered the underground plastic piping for petrol filling stations with the first polyethylene piping used by Shell Sweden in 1981. The retail sector with petrol filling stations has used PE-based underground piping since the early 1980s. With increased...
Author(s) : Andersson
The lifetime of plastic pipes has been studied at Bodycote Polymer AB for more than 30 years. This paper will compare two test methodologies for evaluating multi-layer pipes. An attempt will be made to investigate antioxidant consumption as a function of exposure time for three different PE based multi-layer pipes...
Author(s) : Oertli, Ifwarson
While guaranteed lifetimes of pressure pipes in use is roughly 50 years, it is commonly accepted that a well designed and manufactured HDPE/MDPE pressure pipe would last as long as 100 years without failures. With ever-growing world population and intensifying pollution, it has become increasingly difficult supplying...
Author(s) : Andersson
The lifetime of plastic pipes has been studied at Bodycote Polymer AB (formerly Studsvik Polymer AB) for more than 27 years. This paper presents some of the factors found to control the lifetime of plastic pipes. How to extrapolate the lifetime of plastic pipes will be presented and discussed. A question will also be...
Author(s) : Ifwarson, Aoyama
This paper presents experimental data for three Japanese polyolefin pipe grades exposed to chlorinated water. The chlorine concentrations used are 0.5, 1 and 3 ppm. Results are presented in creep rupture diagrams. The results are compared with hydrostatic pressure tests using 0 ppm of chlorine. Extrapolations using...
Author(s) : Leijstrom, Ifwarson
This paper presents experimental evidences and experiences obta~nedfrom the use of the so-called Miner's rule for determination of lifetime expectancies of plastic pipes subjected to varying testing conditions, i.e. altering temperatures and pressures. Results obtained from some unique long-term pressure tests of PE,...
Author(s) : Leijstrom, Ifwarson
This paper presents results and experiences obtained at Studsvik Material AB from the use of the Standard Extrapolation Method (SEM) according to I S O n R 9080. Results obtained from SEM calculations are demonstrated in creep rupture curves for pipe materials of PE, PP and PEX. Attention is also given to problems...
Author(s) : Gedde, Smith, Ifwarson, Viebke
Polyolefin pipes subjected to extensive hoop stresses fail in a ductile manner (stage I). At lower stresses failure is brittle and may in certain cases be preceded by degradation of the polymer (stage 111). Reviewed in this paper are the changes in polymer structure and antioxidant concentration profiles preceding the...
Author(s) : Ifwarson, Leijstroem
The lifetime of plastic pipes has been studied at Studsvik for nearly 20 years. This paper presents results obtained from hydrostatic pressure testing of pipes made from polyethylene, crosslinked polyethylene and polypropylene. Examples of how different factors influence the lifetime of plastic pipes are explained in...
Author(s) : Eriksson, Ifwarson
Since 1978 STUDSVIK has been testing a PEMoD-grade from Unifos Kemi AB for applications in the temperature range 30 - 60 C. The aim has been to study the long term properties of the material and thus to enable its life to be determined. Pressure testing has show; that the material is expected to last for 50 years at...
Members of the Association
