scholarly journals Effect of joint contamination on the quality of butt-fused high-density polyethylene (HDPE) pipe joints

2002 ◽  
Vol 29 (5) ◽  
pp. 787-798 ◽  
Author(s):  
Jack Q Zhao ◽  
Lyne Daigle ◽  
Denis Beaulieu
Keyword(s):  
Failure Criterion ◽  
High Density Polyethylene ◽  
Quantitative Methods ◽  
Failure Modes ◽  
High Density ◽  
Welding Interface ◽  
Hdpe Pipe ◽  
Pipe Joints ◽  
Joint Quality

Butt fusion is an effective method for joining high-density polyethylene (HDPE) pipe on job sites. However, there is lack of quantitative methods to evaluate pipe joint quality. The objective of this study was to develop such a quantitative approach to determine the effect of joint contamination on the quality of the fused joints. The study included testing a total of 21 butt-fused HDPE pipe joints that were made under different dust conditions. The results of the tests were then used to determine the effect of dust contamination on the quality of the fused joints. Microscopic examination of the fracture surfaces of the test specimens showed that not all the contaminants at the welding interface were squeezed out into the beads formed during the fusion process. Four failure modes were identified and a failure criterion was established to categorize the quality of a fused joint into four grades: bad, poor, good, and excellent. Among the properties of the materials considered, tensile energy to break (TEB) and maximum strain were found to be the most acceptable parameters for distinguishing between joints of different quality. Furthermore, the results showed that under optimum joining conditions, the quality of butt-fused joints can be as good as that of the parent pipe.Key words: polyethylene pipe, butt fusion, joint contamination, tensile energy to break, failure criterion.

Experimental Studies on J-Integral of Welded Buried High-Density Polyethylene Pipes

2011 ◽  
Vol 291-294 ◽  
pp. 1116-1121 ◽  
Author(s):  
Fang Juan Qi ◽  
Jian Li ◽  
Zhi Juan Yang ◽  
Min Fang
Keyword(s):  
High Density Polyethylene ◽  
Failure Modes ◽  
Welded Joint ◽  
Experimental Studies ◽  
Welding Process ◽  
Fracture Initiation ◽  
High Density ◽  
Fracture Parameter ◽  
J Integral ◽  
Hdpe Pipe

Investigation shows that one of the failure modes of HDPE pipe is the crack slowly grows across the thick direction and leads to failure at last. So that it is very important to study the resistance to crack initiation properties of HDPE pipe and its butt-fusion welded joint. The J-integral is applied to character the fracture initiation of a tough polymer for which the concept of linear elastic fracture mechanics (LEFM) are inapplicable for reasonably sized specimen due to extensive plasticity. In this paper, the multiple specimen resistance curve technique was employed for J-integral. The normal single side notched three-point bend (3PB) specimen was used to study the characteristic fracture parameter of high-density polyethylene pipe and its butt-fusion joints at different temperature. Testing results show that values of characteristic fracture parameter are affected by the welding process and experimental temperature respectively. The toughness value of HDPE butt-fusion joint is lowered than that of HDPE pipe. With the temperature decreasing, the toughness value of HDPE pipe and Butt-fusion welded joint decrease. And the same time testing results also show that J-integral can describe the fracture character of high-density polyethylene exactly. Testing results can be used for the engineering design and failure analysis of HDPE pipe.

Study on Fracture Properties of High-Density Polyethylene (HDPE) Pipe

2004 ◽  
Vol 261-263 ◽  
pp. 153-158 ◽  
Author(s):  
Fang Juan Qi ◽  
Li Xing Huo ◽  
You Feng Zhang ◽  
Hong Yang Jing
Keyword(s):  
Welded Joints ◽  
High Density Polyethylene ◽  
Failure Modes ◽  
Welded Joint ◽  
High Density ◽  
Replica Method ◽  
Silicon Rubber ◽  
Hdpe Pipe ◽  
Fusion Welded Joints ◽  
Pipe Materials

Butt-fusion welding is the main technology to join high-density polyethylene (HDPE) plastic pipes, which are widely used in transport the water, gas and corrosive liquid. Investigation shows that one of the failure modes of HDPE pipe is the crack slowly grows across the thick direction and leads to failure at last, so that it is very important to study the resistance to crack initiation of HDPE pipe and its butt-fusion welded joint. In this study, the elastic-plastic fracture mechanics parameter, crack opening displacement (COD) is used to describe the fracture initiation behaviors for the HDPE materials and its butt-fusion welded joints. The resistance to initiation fracture of HDPE pipe materials and butt-fusion welded joints were investigated at different temperature by using multiple specimen resistance curve method and silicon-rubber replica method. The results show that saturation initial crack COD- δis of HDPE pipe materials and butt-fusion welded joints decreases with the decreasing temperature. The δis of butt-fusion welded joints is lower than that of HDPE pipe materials. Investigation also proved that the silicon-rubber replica method is more suitable for HDPE engineering material than the multiple specimen method. At the same time the statistic distribution of the δis of HDPE butt-fusion welded joint was conducted. The results show that the value of the δis has the statistic variance inherently. The optimum fitting distribution of COD is Weibull distribution with three parameters.

Determination of Updated Fatigue Properties of PE 4710 Cell Classification 445574C High Density Polyethylene

2014 ◽  
Author(s):  
Timothy M. Adams ◽  
Shawn Nickholds ◽  
Douglas Munson ◽  
Jeffery Andrasik
Keyword(s):  
Carbon Steel ◽  
Pressure Vessel ◽  
High Density Polyethylene ◽  
Nuclear Power ◽  
Fatigue Testing ◽  
High Density ◽  
Labor Costs ◽  
Cell Classification ◽  
Service Water ◽  
Hdpe Pipe

For corroded piping in low temperature systems, such as service water systems in nuclear power plants, replacement of carbon steel piping with high density polyethylene (HDPE) is a cost-effective solution. Polyethylene pipe can be installed at much lower labor costs that carbon steel pipe and HDPE pipe has a much greater resistance to corrosion. The ASME Boiler and Pressure Vessel Code, Section III, Division 1 currently permits the use of non-metallic piping in buried safety Class 3 piping systems. Additionally, HDPE pipe has been successfully used in non-safety-related systems in nuclear power facilities and is commonly used in other industries such as water mains and natural gas pipelines. This report presents the results of updated fatigue testing of PE 4710 cell classification 445574C pipe compliant with the specific Code requirements. This information was developed to support and provide a strong technical basis for material properties of HDPE pipe for use in ASME Boiler and Pressure Vessel Code, Section III New Construction and Section XI repair or replacement activities. The data may also be useful for applications of HDPE pipe in commercial electric power generation facilities and chemical, process and waste water plants via its possible use in the B31 series piping codes. The report provides fatigue data in the form of Code S-N curves for fusion butt joints in PE 4710 cell classification 445574C HDPE pipe.

scholarly journals Prolonged Storage of Lemons Using Individual Seal-packaging

1990 ◽  
Vol 115 (2) ◽  
pp. 251-255 ◽  
Author(s):  
E. Cohen ◽  
S. Lurie ◽  
B. Shapiro ◽  
S. Ben-Yehoshua ◽  
Y. Shalom ◽  
...  
Keyword(s):  
Water Potential ◽  
Water Relations ◽  
High Density Polyethylene ◽  
Storage Period ◽  
High Density ◽  
Prolonged Storage ◽  
Citrus Limon ◽  
Plastic Film ◽  
Maturity Indices

`Eureka' lemons [Citrus limon (L.) Burro. f.] treated for commercial storage were held for 6 months at 13C. One-half of the fruits were individually sealed in high-density polyethylene (HDPE) plastic film and half not sealed. The HDPE-seaIed lemons showed little change in the water relations characteristics, while unsealed lemons lost weight and decreased in water potential throughout the storage period. The maturity indices in the two treatments were generally similar during the first 3 months of storage, after which maturation of wrapped fruit was slower than that of the control. The overall marketable quality of the fruit was higher in HDPE-sealed lemons than in unsealed. From these results, it appears feasible to introduce seal packaging in packing lines where lemons will be placed in extended storage.

scholarly journals Influence of Backfill Compaction on Mechanical Characteristics of High-Density Polyethylene Double-Wall Corrugated Pipelines

2019 ◽  
Vol 2019 ◽  
pp. 1-24 ◽  
Author(s):  
Hongyuan Fang ◽  
Peiling Tan ◽  
Bin Li ◽  
Kangjian Yang ◽  
Yunhui Zhang
Keyword(s):  
Finite Element ◽  
High Density Polyethylene ◽  
Three Dimensional ◽  
Local Buckling ◽  
Element Model ◽  
High Density ◽  
Model Matching ◽  
Exterior Wall ◽  
Finite Element Software ◽  
Hdpe Pipe

For flexible pipelines, the influence of backfill compaction on the deformation of the pipe has always been the focus of researchers. Through the finite element software, a three-dimensional soil model matching the exterior wall corrugation of the high-density polyethylene pipe was skillfully established, and the “real” finite element model of pipe-soil interaction verified the accuracy through field test. Based on the model, the strain distribution at any position of the buried HDPE pipe can be obtained. Changing the location and extent of the loose backfill, the strain and radial displacement distributions of the interior and exterior walls of the HDPE pipe under different backfill conditions when external load applied to the foundation were analyzed, and the dangerous parts of the pipe where local buckling and fracture may occur were identified. It is pointed out that when the backfill is loose, near the interface between the backfill loose region and the well-compacted region, the maximum circumferential strain occurs frequently, the exterior wall strain is more likely to increase greatly on the region near crown or invert, the interior wall strains increase in amplitude at springline, and the location of the loose region has a greater influence on the strain of the pipe than the size of the loose area.

Application of Nondestructive Testing in Quality Controlling of High-Density Polyethylene Silicore Plastic Duct

2013 ◽  
Vol 470 ◽  
pp. 693-696
Author(s):  
Bai Yan Gong ◽  
Yu Hong Lu ◽  
Juan Ren
Keyword(s):  
Nondestructive Testing ◽  
Product Quality ◽  
High Density Polyethylene ◽  
High Density ◽  
Important Indicator ◽  
Breaking Elongation ◽  
Sampling Inspection ◽  
Weight Impact ◽  
Falling Weight

Some key quality problems has been exposed in several years of quality supervision sampling inspection of industry products for HDPE silicore plastic duct, such as dimension, breaking elongation, performance of falling weight impact and ring stiffness. Quality consistency is an important indicator in evaluating product quality. Nondestructive testing can be used to evaluate the quality of the whole pan and batch of silicore plastic duct, and it will play important role in product quality controlling.

scholarly journals Effect of thawing on the quality of frozen mechanically deboned meat

1990 ◽  
Vol 62 (5) ◽  
pp. 407-415
Author(s):  
L. Riihonen ◽  
P. Linko
Keyword(s):  
High Density Polyethylene ◽  
High Density ◽  
Quality Product

The effect of thawing conditions on the quality of mechanically deboned beef (MDB) and mechanically deboned pork (MDP) recovered using a pressure-based Inject Star deboner was investigated. Samples were recovered using a freshly disinfected machine, and immediately packed in 3 kg portions in high density polyethylene (HDPE)-coated cartons or in Cryovac vacuum bags. Three methods of thawing were used: microwave thawing and thawing at +4°C and at +21°C. All samples were analysed chemically and microbiologically immediately after thawing. Microwave thawing resulted in a better quality product (P

Dynamic Testing of High Density Polyethylene Vent and Drain Configurations

2012 ◽  
Author(s):  
Douglas Munson ◽  
Timothy M. Adams ◽  
Shawn Nickholds
Keyword(s):  
Carbon Steel ◽  
High Density Polyethylene ◽  
Nuclear Power ◽  
Power Plants ◽  
Dynamic Testing ◽  
High Density ◽  
Steel Pipe ◽  
Labor Costs ◽  
Service Water ◽  
Hdpe Pipe

For corroded piping in low temperature systems, such as service water systems in nuclear power plants, replacement of carbon steel pipe with high density polyethylene (HDPE) pipe is a cost-effective solution. HDPE pipe can be installed at much lower labor costs than carbon steel pipe, and HDPE pipe has a much greater resistance to corrosion. This paper presents the results of the seismic testing of selected vent and drain configurations. This testing was conducted to provide proof of the conceptual design of HDPE vent and drain valve configurations. A total of eight representative models of HDPE vent and drain assemblies were designed. The models were subjected to seismic SQURTS spectral acceleration up to maximum shake table limits. The test configurations were then checked for leakage and operability of the valves. The results for these tests, along with the test configurations, are presented. Also presented are the acceleration data observed at various points on the test specimens.

Modern Bimodal High Density Polyethylene for the Nuclear Power Plant Piping System

2009 ◽  
Author(s):  
Adel N. Haddad
Keyword(s):  
High Density Polyethylene ◽  
Nuclear Power ◽  
Large Diameter ◽  
Water System ◽  
High Density ◽  
Nuclear Industry ◽  
Piping System ◽  
Service Water ◽  
Hdpe Pipe ◽  
Related Service

Originally introduced in the 1990s, bimodal HDPE, pipe resins are still finding new niches today, including even nuclear power plants. HDPE pipe grades are used to make strong, corrosion resistant and durable pipes. High density polyethylene, PE 4710, is the material of choice of the nuclear industry for the Safety Related Service Water System. This grade of polymer is characterized by a Hydrostatic Design Basis (HDB) of 1600 psi at 73 °F and 1000 psi at 140 °F. Additionally bimodal high density PE 4710 grades display >2000 hours slow crack growth resistance, or PENT. HD PE 4710 grades are easy to extrude into large diameter pipes; fabricate into fitting and mitered elbows and install in industrial settings. The scope of this paper is to describe the bimodal technology which produces HDPE pipe grade polymer; the USA practices of post reactor melt blending of natural resin compound with black masterbatch; and the attributes of such compound and its conformance to the nuclear industry’s Safety Related Service Water System.

Tensile Stress-Strain Properties and Elastic Modulus of PE 4710 Cell Classification 445574C High Density Polyethylene Pipe Material

2013 ◽  
Author(s):  
Timothy M. Adams ◽  
Jie Wen ◽  
Shawn Nickholds ◽  
Douglas Munson
Keyword(s):  
Elastic Modulus ◽  
High Density Polyethylene ◽  
Tensile Testing ◽  
Axial Direction ◽  
Tensile Tests ◽  
High Density ◽  
Pipe Material ◽  
Yield Strain ◽  
Cell Classification ◽  
Hdpe Pipe

For corroded piping in low temperature systems replacement of buried carbon steel pipe with high density polyethylene (HDPE) pipe is a cost-effective solution. The ASME Boiler and Pressure Vessel Code, Section III, Division 1, Code Case N755-1 currently permits the use of HDPE in buried Safety Class 3 piping systems. This paper presents the results of tensile testing of PE 4710 cell classification 445574C pipe compliant with the requirements of Code Case N755-1. This information was developed to support and provide a strong technical basis for tensile properties of HDPE pipe. The data may also be useful for applications of HDPE pipe in commercial electric power generation facilities and chemical, process, and waste water plants via its possible use in the B31 series piping codes. The paper provides values for yield stress, yield strain, ultimate strain, and elastic modulus. The standard tensile tests were conducted consistent with the requirements of ASTM D638-10. Specimens were cut in the axial direction from cell composition PE 4710 cell classification 445574C HDPE piping spools. In addition, the results are compared to previous tensile testing conducted on the PE 3608 cell classification 345464C and PE 4710 cell classification 445474C HDPE materials.

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