Plastic Pipes Conference Association # 2023 Lake Buena Vista
James F. Mason, Akshay Ponda, Hermann van Laak, Tobias Bauer
The long-term strength of unplasticized polyamide 12 (PA-U12) has been characterized using standard methods for plastic pressure pipe during the qualification process for use in buried piping systems for natural gas delivery operating at low ambient temperatures, usually less than 20 to 30°C at pressures previously served only by steel pipe.
The high strength characteristics of the material also made it interesting as a steel substitute for buried and above-ground industrial pressure pipe applications. So far, typical geometries are diameters up to 6 inch (162 mm) with wall thicknesses up to DR9. Assuming a design factor of 0.63 applied to the PPI TR-4 listed HDB, DR9 PA-U12 pipes have a maximum pressure at 23°C of 496 psig (3.4 MPa), although design pressures will typically be lower. These industrial systems can operate at much higher temperatures, up to ~ 50°C for above-ground installations in pipe supports or up to ~ 65°C for surface-laid oilfield pipes. Design engineers need the temperature dependent strength curves to properly design a thermoplastic pressure piping system. Therefore, the regression curves have been extended by LTHS tests up to 120°C. Corresponding test durations enabled to define the location of knees with determination of second branches. These branches are caused by hydrolytic degradation of the polymer resulting in brittleness of the polyamide after long times at elevated temperature in sufficiently wet environments or services. The first appearance of a knee is at 60° C and approximately 44 years.
This paper describes various standards to which PA-U line pipe and materials must conform, and the development of standardized, temperature dependent, long-term strength reference curves for PA-U12 pressure pipe, including the transition from ductile to brittle behavior at long times and high temperatures. These curves have been standardized first in DVS and followed by ISO based on the combined LTHS data of pipes made from two different PA-U12 180 compounds and one PA-U11 180 compound. An example of a typical PA-U12 180 pipe design is presented, applying chemical resistance derating factors for oil and gas applications in the design process.
Related papers
Author(s) : Ajay Taraiya, Peter Degenhart, Mark Boerakker
In PPXX, a technology was presented for the first time that could bi-axially orient polyolefin pipes. With this technology, it is possible to prepare pipes that have a performance far beyond the standard ones. One approach to achieving this performance is via a continuous in-line process. To optimize the in-line...
Author(s) : Olivera Bilic, Vivek Rohatgi, Brody Peterson, David Hukill
Demand for conduit pipe is expected to surge globally due to rapid industrialization and urbanization in residential and commercial sectors. Just in the U.S., according to Market Research analysis, expected growth of the plastic conduit pipe market is at a CAGR of more than 5% over the next ten years. In response to...
Author(s) : Joe Babcanec, P.E., Issam Khoury, Ph.D, P.E., Shad Sargand,
The use of corrugated HDPE and PP pipe for gravity flow storm sewers is a growing trend throughout the United States. Many of these drainage pipes are buried in shallow cover conditions under roads with heavy traffic. It is well established that thermoplastic pipe installations under shallow cover respond differently...
Author(s) : Yi Zhong, Qianshi Ma, Haihua Yu
BSTRACT The residential district adopts central heating for low temperature radiators system. Due to the disrepair of the secondary heating pipe network that pipe from heat exchange station to user entrance, the running, leaking, dripping and leakage are serious, and the accidents occur frequently. The heat...
Author(s) : Robin Bresser, Ilari Aho, Shima Holder, Tijana Duric, Kaisa Suvilampi
Through innovation and experience, PEX pipe solutions have been enabling comfortable heating and safe plumbing with a successful 50-year track record. They are an important facilitator of the green energy transition and the ambitious climate targets of, for example, the European Union (EU) Green Deal by enabling...
Author(s) : Amster Howard
This paper explores the use of a composite soil stiffness as a valuable design tool to consider when a pipeline traverses through poor soil conditions. Thermoplastic pipe are flexible pipe and require good soil support at the sides of the pipe to minimize deflection. However, sometimes the trench walls are weak soils...
Author(s) : Dr. Michael Pluimer, Sara Stone
The Notched Constant Ligament Stress test (NCLS test, ASTM F2136)[1] is a test method that measures the slow crack growth in High Density Polyethylene. The NCLS test requires a notch on all test specimens to act as a stress concentration at that point so crack propagation can be easily predicted and studied. In...
Author(s) : Sunwoong Choi, Robert Stakenborghs , Pyeongan Lee, Byoungho Choi
This work developed a hydro-axial tension (HAT) test as a whole pipe axial tensile test and applied to evaluate the polyethylene (PE) pipe and fusion joints containing various flaws. HAT test was designed to utilize hydrostatic pressure to cause axial tension in pipes. The experimental and numerical analysis was...
Author(s) : Jacob John, Suresh Shenoy, Patrik Roseen
Cross-linked polyethylene (PEX) pipes continue to gain popularity in plumbing and indoor climate applications around the globe. This study focuses on increasing the sustainability of PEX pipes by utilizing recycled PEX and production waste streams into PEX production. Different methods available for recycling and the...
Author(s) : Aisha Khaleel, Suleyman Deveci, Sulistiyanto Nugroho, Fatima AlHameli
The use of polyethylene pipes in transportation networks of pressurized water and gas have shown superb performance over the history. High density, high-molecular-weight, and bi-modal polyethylene materials, known as PE80, PE100 and PE100RC, have successfully served the market for many years in standard applications....
Author(s) : Jessica Hinczica, Mario Messiha, Florian Arbeiter, Gerald Pinter
In Europe, only 1.8 million tons of recycled material is processed in new products within the building and construction sector [1]. Recyclates and blends of recyclates with virgin materials are already used for different products in the plastic pipe industry, such as cable trays, or storm water management...
Author(s) : Jiyong Park, JaeHyuck Han, YoungGu Kim, Eunjin Park
This study investigates the influence of various parameters on polymer design to determine the slow crack growth. HDPE(High Density Polyethylene) materials with different molecular weight distribution and comonomer content for PE100-RC pipe were investigated with cracked round bar test. The cracked round bar test...
Author(s) : Michael Pluimer, Christian Herrild, Patrick Vibien
With enhanced interest in a circular economy and the potential use of recycled HDPE within HDPE conduit, a research project was undertaken to investigate the necessary technical requirements when using recycled HDPE. High Density Polyethylene (HDPE) conduit is a durable product designed to protect cables...
Author(s) : Mitsuaki TOKIYOSHI, Yutaka SAWADA, Yasuhiko OTSUKI, Kensei INOUE, Takashi KURIYAMA, Toshinori KAWABATA
Polyethylene reinforced with short glass fibres (PE-sGF) pipe, manufactured by combining short fiber glass (sGF) with PE100 as a reinforcing material, has a higher pipe rigidity in the pipe circumferential direction than that of PE100 because of the reinforcing effect of the reinforcing material and a performance...
Author(s) : Kevin White, Shad Sargand
The current standard of practice for the installation of agricultural mains is in accordance with ASTM F449, Standard Practice for Subsurface Installation of Corrugated Polyethylene Pipe for Agricultural Drainage or Water Table Control. ASTM F449 has several limitations. Currently, the allowable maximum height of...
Author(s) : Carine Lacroix, Philippe Louvel, Danielle Mark, Dominique Gueugnaut
A test program was carried out on two Polyamide resins, Polyamide 11 (PA11) and Polyamide 12 (PA12), both certified for gas networks. Polyamide’s advantage lies in its implementation, similar to that of polyethylene, and its properties allowing it to operate at up to 18 bar for gas, all other conditions being equal....
Author(s) : Chantz Denowh, Robert Stakenborghs, Liang Yu
The use of spoolable reinforced thermoplastic pipe (RTP) technologies in the onshore oil and gas industry has expanded significantly over the past decade. It is anticipated that interest will only continue to grow as oil and gas operators transition to transporting alternative fuels such as hydrogen and carbon...
Author(s) : Amster Howard
This paper focuses on the confusing plethora of choices that a design engineer in the United States faces when selecting installation instructions for buried pressure thermoplastic pipelines. For polyethylene pipe, the decision is between AWWA Manual M55, ASTM D2774, ASTM F1668, the PPI Handbook, MAB-3, PE Field...
Author(s) : Chris Greggs
Much has been done to improve the quality and efficiency of HDPE pipe installations over the years. Now, a totally new concept for fusion where the machine meets the pipe where it lays to improve worksite safety, boost jobsite efficiency, and minimize the amount of time spent between fusions has been developed. This...
Author(s) : Jay Parvez, Richard Nichols
All thermoplastic and thermoset pipes must consider the impacts of cyclic loading on overall performance. Since its first use, PVC pipes have been tested for its resilience to such loading. As testing evolved over time, the method to determine cyclic capacity for gasketed PVC pipes has improved. Previously, the...
Members of the Association
