Case Study on Failures of Thermoplastics Pipeline Systems

2015 ◽  
Vol 1111 ◽  
pp. 275-282
Author(s):  
Marius Cocard ◽  
Alin Constantin Murariu ◽  
Emil Moldovan ◽  
Claudiu Burian
Keyword(s):  
Natural Gas ◽  
High Density Polyethylene ◽  
Potable Water ◽  
High Density ◽  
Manufacturing Companies ◽  
Pipeline Systems ◽  
Pipeline Networks ◽  
Water Pipeline

The paper presents some of the most significant situations of tests realised on high density polyethylene pipeline networks from Romania, designed for fluids and gases, which failed during 2008-2014. The inspected objects were assemblies or welded components made of pipes and fittings, as parts of the natural gas and potable water pipeline. The inspections on various assemblies and weldments have identified a number of nonconformities, which have led to failures, generally recorded after welding, during operation. Based on the investigation results, a number of comments and recommendations have emerged, useful for manufacturing companies and for the clients, which could ensue increasing the safety in operation of the high density polyethylene pipeline systems.

Pressure Effects on the Lifetime of Gas High Density Polyethylene Pipes

2021 ◽  
Author(s):  
Yang Wang ◽  
Hui-qing Lan ◽  
Tao Meng ◽  
Bing Wang ◽  
Du du Guo ◽  
...  
Keyword(s):  
Natural Gas ◽  
Induction Time ◽  
High Density Polyethylene ◽  
Reaction Rate ◽  
Low Pressure ◽  
Gas Pressure ◽  
High Density ◽  
Pressure Effects ◽  
Polyethylene Pipes ◽  
Hdpe Pipes

Abstract The purpose of this study was to propose low gas pressure effects on lifetime of natural gas high density polyethylene (HDPE) pipes by thermal-oxidative aging (TOA). The new method to assess the lifetime of HDPE natural gas pipes is based on gas pressure testing. An approach to monitor oxidative induction time (OIT) has been used to predict lifetime. Natural gas HDPE pipes were used to evaluate the effects of low gas pres-sures on oxidative induction time. In order to emphasize the pressure effects, relatively low temperatures at 45, 55, 65 and 75 °C were utilized for the exposure. The low-pressure conditions were created using air at levels of 0, 0.1, 0.2, 0.3 and 0.4 MPa. The property of high density polyethylene pipes was effectively moni-tored using the low pressure oxidative induction time (OIT) test. The results show that the aging reaction rate of high density polyethylene pipes increased exponentially with temperature and gas pressure according to the Arrhenius equation. Analytical models were developed to predict the aging reaction rate and lifetime of natural gas HDPE pipes.

Inductive quantification of energy absorption of high-density polyethylene foam for repeated blunt impact

2020 ◽  
Vol 234 (3) ◽  
pp. 531-545
Author(s):  
Patrick Drane ◽  
Marisel De Jesus-Vega ◽  
Murat Inalpolat ◽  
James Sherwood ◽  
Nese Orbey
Keyword(s):  
Energy Absorption ◽  
High Density Polyethylene ◽  
High Density ◽  
Repeated Loading ◽  
Material System ◽  
Impact Properties ◽  
Prototype Development ◽  
Physical Measurements ◽  
Blunt Impact

Foams are used in a variety of impact energy absorption applications because of their ability to engage in large deformations under steady load transfer during the cell collapse. Quantification of the energy absorption capabilities of foams, including those resulting from repeated loading and unloading, is critical to both modeling and prototype development of systems utilizing these important materials. This paper details a novel process of characterizing a cross-linked high-density polyethylene foam for its applicability within helmet liners designed for low-velocity blunt impact. The foams are characterized using various forms of compression testing and physical measurements. The analyses include examination of the tangent modulus, strain hardness, energy absorption ideality, and energy absorption efficiency. Together, these analyses identify the regions of changing behavior of the nonlinear impact absorption material system. A case study for the materials is presented, which reveals that the examined high-density polyethylene foam exhibits some of the most efficient impact properties during the first impact. However, this case study also identifies that those impact properties can reduce significantly, e.g. a 55% increase in stress in the case of a 0.50 strain-level deformation in the first impact, for a subsequent impact after only a 120 s rest period. The novel combination of testing and analysis presented within this paper enables the developer of a foam energy absorption system to advance their interrogation of foams for repeated large strain deformations and temperature variations.

scholarly journals Studies and Research on the Electrical Resistance of the Polyethylene Insulation Used for the Chemical Protection of the Steel Pipelines Intended for the Natural Gas Distribution

2017 ◽  
Vol 54 (1) ◽  
pp. 63-66
Author(s):  
Stefan Mihai Filip ◽  
Razvan George Ripeanu ◽  
Eugen Avrigean
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Electrical Resistance ◽  
High Density Polyethylene ◽  
High Density ◽  
Metal Corrosion ◽  
Gas Distribution ◽  
Chemical Protection ◽  
Mechanical Factors ◽  
Different Thickness

The paper aims to find solutions to some of the problems the staff operating the natural gas networks have to face, which are the low, medium and high pressure, and the corrosion of the steel pipelines. This metal corrosion can be dealt with by insulating it through various procedures, the latest being the different thickness polyethylene strips insulation. The goal of the paper is to observe the insulation areas on the pipeline which can be destroyed by mechanical factors during operation and the method of remedying these faults with high density polyethylene strips.

scholarly journals Study On Temperature Distribution In T Fittings - Polyethylene Natural Gas Pipes Assemblies

2015 ◽  
Vol 67 (1) ◽  
pp. 67-72
Author(s):  
Eugen Avrigean
Keyword(s):  
Temperature Distribution ◽  
Natural Gas ◽  
High Density Polyethylene ◽  
High Density ◽  
Gas Distribution ◽  
Influence Of Temperature ◽  
Polyethylene Pipes ◽  
Operational Safety

Abstract The present paper intends to approach theoretically and experimentally an important topic concerning the operational safety of the polyethylene pipes used in natural gas distribution. We discuss the influence of temperature in the high density polyethylene elbows during welding to the polyethylene pipes.

An Area-Depth Approximation Model of Microdrilling on High-Density Polyethylene Soft Films Using Pulsed Laser Ablation

2019 ◽  
Vol 7 (4) ◽  
Author(s):  
Sandeep Ravi-Kumar ◽  
Xiao Zhang ◽  
Benjamin Lies ◽  
Liangkui Jiang ◽  
Hantang Qin
Keyword(s):  
Laser Ablation ◽  
High Density Polyethylene ◽  
Pulsed Laser ◽  
Surface Damage ◽  
High Density ◽  
Approximation Model ◽  
Simulation Validation ◽  
Nanosecond Pulsed Laser ◽  
Reduced Surface

Abstract Microdrilling based on laser ablation has been widely applied for manufacturing micro-/nanofeatures on different materials as a noncontact thermal removal approach. It has the advantages of high aspect ratio manufacturing capability and reduced surface damage. However, laser ablation is a complicated process that is challenging to model. In this paper, a standardized modeling procedure was demonstrated to predict the area and depth of laser ablation based on experimental study and simulation validation. A case study was conducted where microdrilling of high-density polyethylene (HDPE) was investigated using a 1064 nm nanosecond pulsed laser. Blind microholes were fabricated on the HDPE samples by ablating under different laser powers and numbers of pulses. Gain factors were defined and determined by the experimental data. A quantitative area-depth approximation model was formulated based on the gain factors. A comparison of the measured and the simulated results of microholes presented average 96.5% accuracy for the area and 85.7% for the depth. This research provided a simple but effective approach to predict dimensions of microholes on various substrates using laser ablation under different laser powers and the numbers of pulses, which could pave the way for development and modeling of laser ablation on polymers.

scholarly journals Energy Efficiency Benchmark in Textile Manufacturing Companies

2021 ◽  
Vol 25 (1) ◽  
pp. 331-342
Author(s):  
Linda Čerdancova ◽  
Kristiāna Dolge ◽  
Edgars Kudurs ◽  
Dagnija Blumberga
Keyword(s):  
Natural Gas ◽  
Statistical Data ◽  
Electricity Consumption ◽  
Manufacturing Companies ◽  
Textile Production ◽  
Regression Methods ◽  
Gas Consumption ◽  
Natural Gas Consumption ◽  
Production Company

Abstract Within the framework of the study a case study is performed, the data provided by a Latvian textile production company on their electricity and natural gas consumption, as well as production volumes over a three-year period have been analysed. The specific indicators of electricity, natural gas and CO2 emissions have been calculated and the obtained results are shown in graphs. The correlation of specific indicators with production volumes was analysed by correlation coefficient and linear regression methods. An analysis of statistical data for the calculated specific indicators over a three-year period has been performed. The obtained results show high seasonality of natural gas consumption and close connection between electricity consumption and production volumes.

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