Technical Basis for Maximum Allowable Indentation Depths in HDPE Pipes for Proposed ASME Section III Code Case on Alternative Requirements to Appendix XXVI for Inspection and Repair

2019 ◽  
Author(s):  
Douglas Scarth ◽  
Prabhat Krishnaswamy ◽  
Phillip Rush ◽  
Douglas Munson
Keyword(s):  
High Density Polyethylene ◽  
Large Diameter ◽  
Cooling Water ◽  
Water Systems ◽  
Parent Material ◽  
Surface Conditions ◽  
Service Water ◽  
Piping Systems ◽  
Technical Basis ◽  
Hdpe Pipes

Abstract Mandatory Appendix XXVI of Section III of the ASME B&PV Code contains rules for the construction of Class 3 polyethylene pressure piping systems. The scope is limited to buried portions of Class 3 service water or buried portions of Class 3 cooling water systems, consisting of PE4710 High Density Polyethylene (HDPE) materials. The minimum Pennsylvania Notched Test (PENT) rating for the HDPE material is 2,000 hours. Appendix XXVI contains acceptance standards for the maximum allowable depths of gouges, cuts or other surface conditions that are characterized as indentations. The acceptance standards are considered to be very restrictive, in particular for large diameter HDPE pipes. Less restrictive maximum allowable indentation depths for pipes with a minimum PENT rating of 2,000 hours were developed based on use of results from tests performed on pressurized HDPE pipes containing flaws in the parent material. These maximum allowable indentation depths were implemented into the new Section III Code Case N-891 on alternative requirements to Appendix XXVI for inspection and repair. The technical basis for the maximum allowable indentation depths is described in this paper.

Technical Basis for Proposed Revisions to ASME Section III Code Case N-891 on Maximum Allowable Indentation Depths in HDPE Pipe to Extend Applicability to PENT Ratings Up to 10,000 Hours

2020 ◽  
Author(s):  
Douglas Scarth ◽  
Prabhat Krishnaswamy ◽  
Phillip Rush ◽  
Douglas Munson
Keyword(s):  
High Density Polyethylene ◽  
Large Diameter ◽  
Surface Conditions ◽  
Test Conditions ◽  
Hdpe Pipe ◽  
Piping Systems ◽  
Current Maximum ◽  
Higher Temperature ◽  
Technical Basis ◽  
Hdpe Pipes

Abstract Mandatory Appendix XXVI of Section III of the ASME B&PV Code contains rules for the construction of Class 3 pressure piping systems comprised of PE4710 High Density Polyethylene (HDPE) with a minimum Pennsylvania Notched Test (PENT) rating of 2,000 hours. Appendix XXVI contains acceptance standards for the maximum allowable depths of gouges, cuts or other surface conditions that are characterized as indentations. The acceptance standards are very conservative, in particular for large diameter HDPE pipes. Less restrictive maximum allowable indentation depths for PE4710 HDPE pipes with a minimum PENT rating of 2,000 hours were previously developed based on analyses of tests on HDPE pipes containing scratches. These less restrictive maximum allowable indentation depths were published in the ASME Section III Code Case N-891 as an alternative to the acceptance standards in Appendix XXVI. The PENT rating of PE4710 HDPE material can significantly exceed 2,000 hours, and the current maximum allowable indentation depths in Code Case N-891 are overly-restrictive for the higher PENT ratings. Maximum allowable indentation depths for PENT ratings up to 10,000 hours have been developed, and are proposed to be implemented into a revision of Code Case N-891 and Appendix XXVI. The technical basis for the maximum allowable indentation depths for these higher PENT ratings is provided in this paper. The proposed revisions to Code Case N-891 include a provision to permit use of results from accelerated PENT testing at a higher temperature and stress level than standard PENT test conditions. The technical basis for the use of results from accelerated PENT testing is also provided in this paper.

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.

B31.1 Compliant Design of CFRP Buried Piping Systems

2015 ◽  
Author(s):  
Neda Stoeva ◽  
Timothy M. Adams ◽  
Tomas Jimenez ◽  
Scott Arnold ◽  
John Uhland
Keyword(s):  
Carbon Fiber ◽  
Composite System ◽  
Large Diameter ◽  
Material Behavior ◽  
Piping System ◽  
Service Water ◽  
Piping Systems ◽  
Cfrp Composite ◽  
Welded Pipe ◽  
Fiber Fabric

This paper presents the implementation of a Carbon Fiber Reinforced Polymer (CFRP) composite system as a long term replacement for a non-safety, non-seismic, non-QA, low pressure service water buried pipeline. The existing pipeline (to be replaced) consists of approximately 1800 feet of large diameter (primarily 54in.), carbon steel, spiral wound, seam welded pipe, which was built and installed using AWWA standards, but is maintained in accordance with the B31.1 Power Pipe Code [1]. The CFRP pipe installation is to be done as an internal repair, and designed to comply with ASME B31.1 as a stand-alone pipe (pressure boundary). In lieu of using the limited evaluation of PCC-2 [2], which is focused on local repairs; a complete design evaluation of the entire piping system to B31.1-2010 is conducted, which is consistent with and acceptable under PCC-2. Since B31.1 does not provide detailed guidance on the design of buried piping systems, the criteria presented in this paper use the base design requirements of B31.1 adjusted to include applied soil and surcharge loads. The selected CFRP repair is the TYFO® Fiberwrap® system which consists of a carbon fiber fabric (CFRP, TYFO SCH-41-2X), and glass fiber fabric (GFRP/dielectric barrier, TYFO SHE-51A), saturated with epoxy. This composite system is built up of unidirectional CFRP layers; thus, the presented design approach also considers anisotropic material behavior, and evaluates the hoop and axial loads and capacities separately. The criteria are presented for plants considering alternative repair and replacement techniques for buried and above ground non-safety pipes.

scholarly journals Selection of materials for biofouling detection in cooling water systems

2017 ◽  
Vol 18 (4) ◽  
pp. 1162-1172
Author(s):  
Joana Melo Mota ◽  
Maria Diná Afonso
Keyword(s):  
High Density Polyethylene ◽  
Vibration Amplitude ◽  
Food Industry ◽  
Cooling Water ◽  
Water Systems ◽  
Vibration Sensor ◽  
Surface Shear Stress ◽  
Surface Shear ◽  
Effective Roughness ◽  
Selection Of

Abstract This work aimed to select materials capable of favouring biofouling build-up in order to develop plain coupons as alternative to expensive commercial biofouling mesh coupons. Plain coupons of copper, stainless steel (SS), polyvinyl chloride (PVC) and high density polyethylene (HDPE) were dipped and tested in a cooling water from a food industry. PVC and HDPE coupons showed promising responses and appear to be preferable since they are corrosion-free. Moreover, an experimental vibration sensor monitored biofilm adhesion on SS and PVC tubular coupons (simulators of the respective sensor tubes), inside which flowed the water aforementioned. The SS sensor tube and tubular coupons displayed the most satisfactory results, i.e. the highest vibration amplitude and the highest adhered biofilm mass, respectively. Biofilm adhesion onto the materials tested depended on their surface shear stress, effective roughness and hydrophobicity, as determined by scanning electron microscopy and goniometry.

Use of Polyethylene (PE) Pipe in Safety-Related, Class 3, Service-Water Piping

2008 ◽  
Author(s):  
Prabhat Krishnaswamy ◽  
Eric M. Focht ◽  
Do-Jun Shim ◽  
Tao Zhang
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Elevated Temperatures ◽  
Slow Crack Growth ◽  
Large Diameter ◽  
Modes Of Failure ◽  
Service Water ◽  
Division 1 ◽  
Piping Systems ◽  
Technical Issues

The ASME Boiler and Pressure Vessel Code Committee (BPVC) has recently published Code Case N-755 that describes the requirements for the use of Polyethylene (PE) pipe for the construction of Section III, Division 1 Class 3 buried piping systems for service water applications in nuclear power plants. The code case was developed by Special Working Group–Polyethylene Pipe (SWG-PP) within Section III (Design) of the BPVC. This paper provides a critical review of the design requirements described in CC N-755 from pressure boundary integrity considerations. The various technical issues that need to be addressed for safety-critical PE piping are discussed in this paper. Specifically, the premise of allowing defects in pipe that are 10% of the wall thickness has been reviewed especially for cases involving large diameter piping [> 304.8 mm (12 inches)] that is to be operated at elevated temperatures as high as 60°C (140°F). One of the common modes of failure in PE piping under sustained internal pressure is due to slow crack growth (SCG) from manufacturing or installation defects in the pipe wall. The effect of pipe diameter and stresses on the crack driving force for a 10% deep flaw is calculated for comparison with the material resistance to SCG at elevated temperatures.

Tensile Testing and Material Property Development of High Density Polyethylene Pipe Materials

2008 ◽  
Author(s):  
Timothy M. Adams ◽  
Siegrid Hall ◽  
Rudolph J. Scavuzzo ◽  
Douglas Munson ◽  
Jeffrey W. Andrasik ◽  
...  
Keyword(s):  
Pressure Vessel ◽  
High Density Polyethylene ◽  
Tensile Testing ◽  
Water Systems ◽  
High Density ◽  
Test Program ◽  
Polyethylene Pipe ◽  
Cell Class ◽  
Service Water ◽  
Division 1

Degradation of service water systems is a major issue facing nuclear power plant owners, and many plants will require repair or replacement of existing carbon steel piping components. High Density Polyethylene pipe has been used in non-safety service water systems for over nine years and found to perform well, but it is not currently permitted in the ASME Section III Boiler and Pressure Vessel Code, Division 1 for use in nuclear safety-related systems. To assist in the implementation of High Density Polyethylene pipe in the ASME Boiler and Pressure Vessel Code, Section III, Division 1 for Safety Class 3 applications, EPRI initiated a High Density Polyethylene pipe and pipe material testing program. This test program includes tensile testing and fatigue testing of High Density Polyethylene piping and piping components and the development of slow crack growth data. To determine the material and engineering properties needed, extensive tensile testing of specimens cut from High Density Polyethylene pipe was conducted. The initial tensile test program was conducted on PE 3408 with cell classification 345464C and a second, not yet finalized, phase was added to test PE 4710 with cell classification 445474C. The data developed during the testing were used to establish ultimate strain, elastic moduli, yield stress and yield strain values for both new and aged materials. Because extruded HDPE properties vary in the hoop and axial directions and the properties are highly affected by temperature, specimens were cut in both the hoop and axial directions and were tested at temperatures ranging from 50° F to 180° F. This paper provides a description and overview of the PE 3408 cell class 345464C test program. In addition, an overview and summary of the test results for the PE 3408 cell class 345464C are provided.

Bending Fatigue Testing of Pipe and Piping Components Fabricated From High Density Polyethylene Materials

2012 ◽  
Author(s):  
Timothy M. Adams ◽  
Douglas Munson ◽  
Siegrid Hall ◽  
Jeffrey W. Andrasik
Keyword(s):  
Pressure Vessel ◽  
High Density Polyethylene ◽  
Fatigue Testing ◽  
Water Systems ◽  
Fatigue Tests ◽  
High Density ◽  
Test Program ◽  
Bending Fatigue ◽  
Service Water ◽  
Division 1

Degradation of service water systems is a major issue facing nuclear power plant owners, and many plants will require repair or replacement of existing carbon steel piping components. High Density Polyethylene piping has been used in non-safety service water systems for over nine years and found to perform well, and is now permitted in the ASME Section III Boiler and Pressure Vessel Code, Division 1 for use in nuclear safety-related systems. To assist in this implementation of High Density Polyethylene piping in the ASME Boiler and Pressure Vessel Code, Section III, Division 1 for Safety Class 3 applications, Electric Power Research Institute initiated a testing program that includes tensile and fatigue testing of High Density Polyethylene piping and components and the development of data to evaluate slow crack growth that can emanate from surface scratches. Straight cantilever bending fatigue tests on PE 4710 pipe with a minimum cell classification of 445474C were previously conducted and the results presented at the 2008 PVP Conference in Chicago, Illinois. The tests were designed to comply with the requirements for fatigue testing given in Mandatory Appendix II of the ASME Boiler and Pressure Vessel Code, Section III, Division 1. Based on the straight pipe tests, Stress Intensification Factors can be calculated for other piping components. This paper reports on follow-on testing of PE 4710 cell classification 445574C piping components. The fatigue testing results showed one of the unique characteristics of High Density Polyethylene piping: a significant decrease in material stiffness from the first few test cycles to a lower value that remains almost constant until failure. Thus, Stress at Failure vs cycles at failure curves and Stress Intensification Factors were determined twice: first based on the initial cycle results and again at the midlife of the fatigue tests. This paper provides a description and overview of the test program, testing methods and materials tested. In addition, an overview and summary of the test program results are provided.

scholarly journals Modeling benzene permeation through drinking water high density polyethylene (HDPE) pipes

2015 ◽  
Vol 13 (3) ◽  
pp. 758-772 ◽  
Author(s):  
Feng Mao ◽  
Say Kee Ong ◽  
James A. Gaunt
Keyword(s):  
Drinking Water ◽  
High Density Polyethylene ◽  
Distribution Systems ◽  
Water Distribution ◽  
Large Diameter ◽  
Small Diameter ◽  
High Density ◽  
Ethyl Benzene ◽  
Constant Input ◽  
Hdpe Pipes

Organic compounds such as benzene, toluene, ethyl benzene and o-, m-, and p-xylene from contaminated soil and groundwater may permeate through thermoplastic pipes which are used for the conveyance of drinking water in water distribution systems. In this study, permeation parameters of benzene in 25 mm (1 inch) standard inside dimension ratio (SIDR) 9 high density polyethylene (HDPE) pipes were estimated by fitting the measured data to a permeation model based on a combination of equilibrium partitioning and Fick's diffusion. For bulk concentrations between 6.0 and 67.5 mg/L in soil pore water, the concentration-dependent diffusion coefficients of benzene were found to range from 2.0 × 10−9 to 2.8 × 10−9cm2/s while the solubility coefficient was determined to be 23.7. The simulated permeation curves of benzene for SIDR 9 and SIDR 7 series of HDPE pipes indicated that small diameter pipes were more vulnerable to permeation of benzene than large diameter pipes, and the breakthrough of benzene into the HDPE pipe was retarded and the corresponding permeation flux decreased with an increase of the pipe thickness. HDPE pipes exposed to an instantaneous plume exhibited distinguishable permeation characteristics from those exposed to a continuous source with a constant input. The properties of aquifer such as dispersion coefficients (DL) also influenced the permeation behavior of benzene through HDPE pipes.

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