Sustained Pressure Test Results for Surface Scratches in PE4710, Cell Classification 445574C High Density Polyethylene Pipe Material

2019 ◽  
Author(s):  
Jason Hebeisen ◽  
Timothy M. Adams ◽  
Douglas Munson
Keyword(s):  
High Density Polyethylene ◽  
Slow Crack Growth ◽  
Crack Depth ◽  
High Density ◽  
Pipe Material ◽  
Cell Classification ◽  
Nominal Diameter ◽  
Diameter Pipe ◽  
Piping Systems ◽  
Different Depths

Abstract Mandatory Appendix XXVI of the ASME Boiler and Pressure Vessel Code (BPVC), Section III, Division 1 currently permits the use of high-density polyethylene (HDPE) in buried safety Class 3 piping systems. There have been concerns about how the slow crack growth (SCG) of HDPE emanating from surface scratches that may occur during fabrication or installation. The current allowable scratch depth in Appendix XXVI is 5% of the pipe wall thickness for pipe 4 inch and less in nominal diameter pipe and 0.040 inch (1mm) for pipe greater than 4 inch nominal diameter. This report presents the results of further investigation into the SCG rates by testing of notched PE 4710 HDPE pipes made from PE 4710 cell classification 445574C bimodal resins that meet the requirements of Appendix XXVI. These tests were conducted by first making razor-cut surface scratches in 4 inch, 8 inch, and 16 inch nominal diameter piping made by three different piping manufacturers using three different resins. The pipes were end-capped and pressure-tested at elevated temperature until failure, or until a prescribed number of test hours were reached. The razor cuts were at different depths and lengths so as to result in a variety of stress intensities, net section stresses, and nominal stresses. Following failure, or after the prescribed number of test hours was reached, the pipe specimens were inspected to determine the amount of SCG. This paper presents the results of the testing and recommended ASME BPVC Appendix XXVI changes for allowable crack depth based on the testing are provided.

Development of Crack Growth Curves and Correlation to Sustained Pressure Test Results for Cell Classification 445574C High Density Polyethylene Pipe Material

2013 ◽  
Author(s):  
Timothy M. Adams ◽  
Jason Hebeisen ◽  
Jie Wen ◽  
Douglas Munson
Keyword(s):  
Crack Growth ◽  
High Density Polyethylene ◽  
Failure Time ◽  
Slow Crack Growth ◽  
Growth Curves ◽  
High Density ◽  
Pipe Material ◽  
Test Results ◽  
Cell Classification ◽  
Failure Times

Code Case N755-1 of the ASME Boiler and Pressure Vessel Code, Section III, Division 1 Code currently permits the use of high density polyethylene (HDPE) in buried Safety Class 3 piping systems. There have been concerns with the Slow Crack Growth (SCG) of HDPE emanating from scratches that may occur during fabrication or installation. The possible use of tensile coupon tests for determining the life span of the pipe with surface scratches could provide a more cost effective testing method than does the use of sustained pressurized crack pipe tests. This paper presents the results of further investigation into the SCG rates of notched PE 4710 HDPE pipe made from a cell classification 445574C bimodal resin. The da/dt versus KI curves were developed from notched coupon testing. Standard fracture methods were then used to predict the failure time of the notched pressurized pipe specimens subjected to long-term hydraulic stress. The results for the SCG depth of the externally notched sustained pressurized pipe tests are provided along with the notched coupon test results. The actual failure times of the notched pressurized pipe tests are compared to the predicted failure times for the same specimens.

Experimental study of the crack depth ratio threshold to analyze the slow crack growth by creep of high density polyethylene pipes

2014 ◽  
Vol 122 ◽  
pp. 22-30 ◽  
Author(s):  
Lucien Laiarinandrasana ◽  
Clémence Devilliers ◽  
Jean Marc Lucatelli ◽  
Emmanuelle Gaudichet-Maurin ◽  
Jean Michel Brossard
Keyword(s):  
Experimental Study ◽  
Crack Growth ◽  
High Density Polyethylene ◽  
Slow Crack Growth ◽  
Crack Depth ◽  
High Density ◽  
Polyethylene Pipes ◽  
Depth Ratio ◽  
Crack Depth Ratio

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.

Application of Crack Layer in Modeling of Slow Crack Growth in High-Density Polyethylene

2013 ◽  
Author(s):  
Haiying Zhang ◽  
Zhenwen Zhou ◽  
Alexander Chudnovsky
Keyword(s):  
Crack Growth ◽  
High Density Polyethylene ◽  
Slow Crack Growth ◽  
Growth Failure ◽  
High Density ◽  
Large Set ◽  
Layer Model ◽  
Crack Layer ◽  
Basic Parameters ◽  
Engineering Polymers

Crack layer model provides a comprehensive foundation for modeling of fracture growth, failure analysis, and lifetime prediction. During the past two decades, it has been widely applied for modeling various aspects of brittle fracture in general. This paper illustrates in details the procedure of implementation by an example of slow crack growth in a commercialized high-density polyethylene undergoing creep conditions. Firstly, we determine experimentally the basic parameters employed in constitutive equations of crack layer model such as draw ratio λ, the specific energy of transformation γtr, and drawing stress σdr, etc.. Secondly, we implement crack layer model numerically in lab-developed “Simulator”. The paper provides a paradigm for implementation of crack layer model in slow crack growth, and a blueprint for potential software development that can be used in ranking and the lifetime assessment of a large set of engineering polymers.

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.

Limit Load of Pre-Cracked Polyethylene Miter Pipe Bends Subjected to In-Plane Bending Moment

2010 ◽  
Author(s):  
Tarek M. A. A. EL-Bagory ◽  
Maher Y. A. Younan ◽  
Hossam E. M. Sallam ◽  
Lotfi A. Abdel-Latif
Keyword(s):  
High Density Polyethylene ◽  
Crack Depth ◽  
Testing Machine ◽  
Bending Moment ◽  
Limit Load ◽  
Factor H ◽  
Bend Angle ◽  
Pipe Bend ◽  
Piping Systems ◽  
Plane Bending

The main purpose of the present paper is to investigate the effect of crack depth on the limit load of miter pipe bends (MPB) under in-plane bending moment. The experimental work is conducted to investigate multi miter pipe bends, with a bend angle 90°, pipe bend factor h = 0.844, standard dimension ratio SDR = 11, and three junctions under a crosshead speed 500 mm/min. The material of the investigated pipe is a high-density polyethylene (HDPE), which is used in natural gas piping systems. The welds in the miter pipe bends are produced by butt-fusion method. The crack depth varies from intrados to extrados location according to the in-plane opening/closing bending moment respectively. For each in-plane bending moment the limit load is obtained by the tangent intersection (TI) method from the load deflection curves produced by the testing machine specially designed and constructed in the laboratory. The study reveals that increasing the crack depth leads to a decrease in the stiffness and limit load of (MPB) for both inplane closing and opening bending moment. Higher values of the limit load are reached in case of opening bending moment. This behavior is true for all investigated crack depths.

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