Papers
Plastic Pipes Conference Association # 2016 Berlin
Maarten Kruijer
To ensure the structural integrity of long term load bearing thermoplastic (like PVC or HDPE/PP) components, the time-dependent behavior of the raw (thermoplastic) material needs to been assessed and integrated in the design procedure. This paper describes how the time-dependent material behavior can be integrated in the design process. As an example, the design of a PVC sewage inspection chamber is elaborated more in detail.
Over the past decades many non-plastic sewage products have been replaced by thermoplastic equivalents. Thermoplastics are more easy to process to a particular complex shape, easier to handle (lighter in weight) and have a lower carbon footprint. On the contrary, thermoplastics in general show time-dependent behavior which is more complex to deal with compared to for instance concrete. Especially, in load-bearing applications, the plastic component is subjected to external loads during its complete lifetime. This leads to the fact that deformations will continue in time and can ultimately lead to premature failure. It is therefore a key issue to have a clear understanding of the time dependent constitutive behavior of the used thermoplastic. In addition, it has to be incorporated in the design methodology for thermoplastic pipes and sewage products.
Having such a design methodology, premature failure can be avoided and effectiveness /competitiveness of thermoplastics over other raw materials is increased as heavy over dimensioning is no longer needed. It aids to reduce the costly trial–and–error time and direct towards a ‘first–time–right’ design. Especially for injection moulded products the (experimental) trial and error approach is costly, as for each design, mould adjustments may be required.
In this paper the design methodology incorporating the time-dependent behavior is presented and applied in the development and optimization of a PVC inspection chamber. An inspection chamber can be installed up to 6 meters deep, and as such, being subjected to a 6m water column (0.6 bar) during its entire lifetime. As a consequence, continuing deformations of the chamber can lead to failure or unfit for usage after a period of time.
To this end, firstly the base material is tested for its time dependent constitutive behavior by creep experiments. Subsequently, a viscoelastic material model is set-up for the PVC and is implemented in a finite element program. Finally, the mechanical (long-term) requirements for the chamber are outlined and the design procedure is used to engineer the PVC chamber to be optimized for its usage.
Related papers
Author(s) : Ricardo Pascual
Social awareness with aspects related to the conservation of the environment and sustainability, the acceptance by citizens of the need to reduce consumption, reuse products, repair as far as possible and, fundamentally, the action of recycling at the end of its life, facilitates the availability of recycled plastics...
Author(s) : Shane Harton, Andrew Sell, Carl Dolgow
The torque rheometer has been the standard instrument used in poly(vinyl chloride) (PVC) quality control (QC) testing for decades. ASTM D2538 has provided standard, comprehensive testing and analysis procedures since 1969 that have allowed the vinyl industry to coalesce around this simple, yet robust, set of...
Author(s) : 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...
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) : Antonio Rodolfo Jr., Vanderley M. John
Unplasticized (U-PVC) ABNT NBR 5647-2 regular industrial pipe samples, with nominal diameter DN 100, outside diameter 110 mm, nominal wall thickness 7.8 mm, Ca/Zn stabilized, were studied using an essential work of fracture (EWF) approach. These pipe samples were also tested for the degree of gelation via...
Author(s) : Cindy Bray
For over two decades, the plastics pipe industry in Australia has aimed to recycle the maximum amount of usable plastic pipe and other suitable materials into new plastic pipes through programs such as take-back schemes and providing collection facilities on manufacturing sites. In Australia long-term sustainability...
Author(s) : Tobias Johnsen, Ole Grøndahl Hansen
With a growing global population that will primarily settle in urban areas, more and more agricultural land will be converted into dwellings, roads etc. As the demand for food in 2050 will be 60% greater than today, a conflict between Sustainable Development Goals 2 (Zero Hunger) and 11 (Sustainable Cities and...
Author(s) : Lucy Croker, Matthew Hynes, Cindy Bray
In Australia, the first Environmental Product Declarations (EPDs) covering plastic pipes were published circa 2015/16 by two local manufacturers, supported by the peak industry association. Although this was a milestone event at the time, the reality was that the broader industry did not understand the information...
Author(s) : Roland Valk, René Hermkens, Sjoerd Jansma
The use of hydrogen gas as an energy carrier is seen as a key component of the energy transition. This creates new challenges, including in relation to the transport and distribution of this gas. The low-pressure (natural) gas distribution grid in the Netherlands currently consists of 64% PVC and is presumed to be...
Author(s) : A. Marangoni
The competitiveness of plastic pipes vs. non plastic pipes for water and sewer networks relies on both a superior performance to cost ratio and environmental benefits that can be offered to the utility industry, across the whole lifecycle of these networks. In order to help the European pipe network owners in...
Author(s) : Tobias Johnsen
To ensure the highest possible quality of plastic pipes for the Nordic market, the Nordic Poly Mark currently only allows virgin material or own reprocessed material. In order to accelerate the circular plastic pipe economy in the Nordics, a partnership between a PVC pipe waste collection system, a PVC pipe producer...
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...
Author(s) : Karin Jacobson, Daniel Ejdeholm
Plastic pipes often have much better corrosion resistance than metallic pipes and have, in addition, the benefits of low weight and flexibility. Thanks to this, they are often used to convey chemicals. There is, however, still a large potential for a much more extensive use of plastic pipes for this application. The...
Author(s) : Ignacio Muñoz
Society has recently lived few strange and peculiar years, to say the least. COVID impacted personal lives, businesses, industries. And it is undeniable, the big elephant in the room arrived years before COVID and will remain much more: CLIMATE CHANGE. As broad as this topic is, this paper focuses on the impact that...
Author(s) : J. Lahoz
An investigation project was launched in 2020 to clarify the relationships between the processing conditions and the design lifetime of PVC-U 250 pipes. Ca/Zn stabilized pressure pipes were extruded with different processing temperatures and characterized by their DSC B-onset temperature and degree of gelation. Their...
Author(s) : Ludo Debever, Peter Sejersen
The Circular Economy Action Plan is a major building block of Europe’s Green Deal, the European Climate Change strategy. It has far-reaching consequences for the entire EU industrial fabric and its business models. The EU’s transition from a linear to a circular economy aims to reduce on natural resources and pave...
Author(s) : Dr. Ricky Selle
Structural behavior of flexible plastic manholes is very different from rigid concrete products. Although this is state-of-the-art knowledge, no international or EN standard exists on structural design of these products. Therefore, traditional soil models and soil pressure coefficients are usually applied if...
Author(s) : Guido Quesada
Spigot bevels (also referred to as chamfers) for plastic pipe joints using elastomeric seals are well-known and often prescribed in standards such as ISO 1452 for PVC-U and 16422 for PVC-O. The most common type of bevel is a simple straight cut at a 15° angle with respect to the pipe axis, leaving approximately 50%...
Author(s) : Guido Quesada, Mark Weih
The Plastic Retainer Ring (PRR) gasket is an old friend of pipe joints, and it is still used among other sealing solutions developed more recently. With origins traced back to the end of the 1960s, it is recognized among the first solutions developed for gasketed plastic pipe joints. It is very likely to have...
Author(s) : Luciana Oriqui, Mauro Adamo Seabra, Antonio Rodolfo Jr.
The Brazilian PVC pipe industry maintains specific mechanisms of intense and continuous evaluation of the products regularly offered to the market. These programs are carried out by an independent third-party technical entity, within known public rules and based on the best practices of conformity assessment. Their...
Members of the Association
