Papers
Plastic Pipes Conference Association # 2014 Chicago
Bill R. Vanhoose, Jarrett A. Nelson, Christa K. McNish, Richard W. Thomas
The Stepped Isothermal Method (SIM) is a form of Time-Temperature Superpositioning (TTS) that involves measuring the creep rate of a sample while it is subjected to a series of isothermal temperature steps. The accelerated temperature results can then be shifted back to room temperature to produce a master-curve. Performing multiple temperature steps on a single specimen reduces the noise associated with sample-tosample variability. This test has been used for over 15 years to characterize the creep behavior of a variety of products made with different polymers. The products include high-strength geotextiles, geogrids, mooring lines, underground storage tanks, and pipe. The polymers evaluated include polyester, polypropylene, polyamides, polyethylene naphthanate (PEN), and polyethylene. The purpose of this study was to validate results obtained by SIM on polypropylene by comparing the SIM results to conventional room temperature creep tests. The results demonstrate that the SIM results correlate well to conventional tests for up to 10,000 hours. Additionally, the SIM results can be considered superior to conventional tests because one can control variables much better over a 24 hour period than a 10,000 hour period.
Related papers
Author(s) : Chris Ampfer, Gene Palermo, Ernest & Oren Lever
This paper looks at the origin of the 10% allowable scratch depth rule for polyethylene (PE) pressure pipe developed in 1971 and research that has been performed over the years since its inception to determine the validity of this rule. The 10% rule has been used by natural gas pipeline operators since the 1970’s to...
Author(s) : Peter Hubbard, Linqing Luo, Andrew Yeskoo, Kenichi Soga, Krista (Moita) Araica, Gus Cicala, Marshall McLeod
Seismically active faults pose a risk to buried water pipelines that can be complicated to quantify. Fault type, slip rate, pipeline geometry, and soil conditions all factor into a complex soil-pipeline interaction. For critical pipelines that cross faults, high-density polyethylene (HDPE) has become an attractive...
Author(s) : Mario Messiha, Britta Gerets, Jan Heimink, Andreas Frank, Florian Arbeiter, Gerald Pinter
A majority of field failure of viscoelastic plastic pipes can be attributed to slow crack growth (SCG) and has become crucial in terms of characterization of newly developed materials – particularly, if they are designed for pressurized pipe applications. In this study, investigations in terms of SCG resistances...
Author(s) : Thomas R. Kratochvilla, Patrick Grünbeck, Christoph Bruckner, Raimund Eremiasch, Harald Wilhelm, Mario Vukelja
In the last decades pipe dimensions of extruded PE pipes have reached new orders of size. Today, PE pipes with outer diameters of up to DN/OD 3500 mm are produced and used for pressure pipe applications like seawater intake/discharge, outfall, sewage and industrial process piping systems. To test the long-term...
Author(s) : Lukas Travnicek, Pavel Hutar, Jan Poduska, Andreas Frank, Florian Arbeiter, Jaroslav Kucera, Jiri Sadilek, Gerald Pinter, Lubos Nahlik
The application of recycled material in pressure piping systems has been considered lately – it was suggested, that the recycled polyethylene could be used as a part of a multilayer pipe together with virgin material. This type of pressure pipes is not availableon the market yet, so their properties can be only...
Author(s) : Kensei INOUE, Mitsuaki TOKIYOSHI, Joji HINOBAYASHI, Takeshi KARINO, Toshinori KAWABATA, Takashi KURIYAMA
As the worldwide problems are over-population, unusual weather like as localized heavy rain and climate change. Against those problem, it has to need new projects to make a new agricultural field, drainage pipeline system and to spread the new underground irrigation system at peat land whereas spots of about 2 million...
Author(s) : Ulrich Schulte, Dr. -Ing. Joachim Hessel
In order to protect the Austrian lakes effectively against the discharge of effluent, a 13 km long pressure pipeline made of high density polyethylene was laid on the bottom of Lake Ossiach back in 1971. The DN355 to DN200 pipes were produced from a first generation HDPE-compound. The classification would have been...
Author(s) : Justin Brandt, Mike Griffin, Tony Cuvo
As plastic pipe gains share in new markets and applications, additional joining methods add further value, enabling continued growth for plastic pipes. To date, definitions of a “fit-for-purpose” mechanical joint for High Density Polyethylene (HDPE) pressure piping systems can vary significantly. As such, mechanical...
Author(s) : Mark Boerakker, Rudy Deblieck, a Harm Caelers, Arno Wilbers, Tine Boonen a DSM, Britta Gerets, Mirko Wenzel
Components made of plastic are facing ever-increasing demands with respect to their production, use and durability. This also holds for gas and drinking water pressure pipes made of high-density polyethylene (PE-HD), where service lifetimes of up to 50 years and in some cases even 100 years are required. One of the...
Author(s) : Britta Gerets, Mirko Wenzel, Kurt Engelsing
The strain hardening test (SHT, ISO 18488 [1]) becomes increasingly important for the characterization of high-density polyethylene (HDPE) grades and pipes made thereof. With regard to small pipe diameters, a smaller test specimen than the one defined in ISO 18488 has been developed. SHT results were demonstrated to...
Author(s) : Hermann van Laak, Jan Heimink, Mario Messiha, Andreas Frank, Christoph Bruckner, Thomas Kratochvilla
For high pressure pipes above maximum operation pressure of 10 bar, this paper emphasizes PA-U12 as the easy to install alternative to steel. It underlines the superb performance of PA-U12 pipes for alternative installation techniques without need for a separate mechanical protection. An unplasticized polyamide 12...
Author(s) : Nolene Byrne, Rasike De Silva, Keith Lenghaus, Tim Hilditch
Plastic pipes have been utilized in the Australian gas distribution network since the early 1970s. The most common plastic type found in Australia is polyethylene (PE), although nylon is extensively used in New South Wales. Early installation of PE pipe was completed using the first generation high density type PE50...
Author(s) : Liang Yu, Akshay Ponda, Dane Chang
Following the development of US shale oil and gas production since 2007, the demand for thermoplastic pipes with better corrosion resistance, and lower installation and operation cost than carbon steel pipe, has been growing significantly. Nylon 12 has been qualified for hydrocarbon transportation in offshore...
Author(s) : Carlos Domínguez, Álvaro Pérez, Nuria Robledo, Cristina González, Beatriz Paredes, Rafael A. García-Muñoz
Last methodologies for fast evaluation of the SCG resistance on polyethylene pipe materials are analyzed in this work and compared with traditional PENT and FNCT tests. Strain Hardening (SH), Crack Round Bar (CRB) and Accelerated Creep Test (ACT) will be good alternatives for evaluating PE100RC resins. Moreover, SH...
Author(s) : Amanda Hawkins, Jason Lawrence, Xiangli Meng
High Density Polyethylene pipes are used in various applications due to the material’s superior chemical resistance, pressure capability, and ductility. For the material to perform at the optimal design criteria, the connections and fabrications must be fused using repeatable procedures that specify proper fusion...
Author(s) : Hiroto Taguchi, Kaori Numata
We elucidated the creep failure behavior of polyamide pipes. We conducted the hydrostatic test and Notched Pipe Test (NPT) at 80 and 90 °C for up to 10000 h for PA pipes whose creep failure behavior has not been fully elucidated yet. In the tests, the change in the failure mode from ductile failure to brittle...
Author(s) : Dominique GUEUGNAUT, Adil BOUJLAL, Aymeric LOPITAUX, Bertrand SEVRE
A special concept has been developed by GRTgaz Research and Innovation Center for Energy (RICE) for temperature mapping at the interface of an electrowelded assembly.The technical solution consists of a tubular piece in place of the real PE pipe, made of a non-weldable polymer with thermal parameters close to those...
Author(s) : Joaquín Lahoz Castillo
Irrigation networks in Spain extensively make use of plastic pressure pipes systems. Some recent failures focus the attention on Rapid Crack Propagation phenomena. Larger high-pressure PVC-u pipes are involved in most incidences detected. The level of gelation of those pipes were measured per EN-ISO 1452-2 test...
Author(s) : Cheng Zhi, Mingyuan Hu, Kaige Duan, Chaoxi Zhou, Dongming Yu
The PE properties are obviously improved by crosslinking modified to TPEX, which can approach to that of PEX, while still remaining thermoplastic. It can be processed by the common forming method of thermoplastic; the products can be hot-melted and the scrap can be processed to be reused. The two-layer structure...
Author(s) : Suleyman Deveci, Senthil K. Kaliappan, Joel Fawaz, Umesh Gadgoli
A series of non-commercial bimodal high density ethylene-α-olefin copolymers with systematically controlled molecular parameters over a wide range that would result in extremely low and high strain hardening modulus were prepared and tested Strain hardening modulus has been published as a standard test method (ISO...
Members of the Association
