Our site uses cookies necessary for its proper functioning. To improve your experience, other cookies may be used: you can choose to disable them. This can be changed at any time via the Cookies link at the bottom of the page.


Correlating Aldyl A and Century PE Pipe Rate Process Method Projections With Actual Field Performance [PE]

 

System Pressure Rating & Residual Life

Plastic Pipes Conference Association # 2004 Milan

Palermo

The recent Department of Transportation Advisory Bulletin, “Notification of the Susceptibility to Premature Brittle-Like Cracking of Older Plastic Pipe” cited lower ductile inner wall Aldyl “A” and Century polyethylene (PE) pipe as two materials that were known to be susceptible to brittle-like cracking or slit failures. Many miles of these materials are still in service in the United States. The key question is – what is the projected life of these PE pipes still in the ground? The Rate Process Method (RPM) is used to project performance (lifetime) of PE materials at their in-ground temperatures and pressures based on both internal pressure as the primary load and secondary loads such as rock impingement and squeeze-off. This paper will provide a discussion on the Rate Process Method. RPM involves exhuming samples of pipe from service and subjecting them to laboratory elevated temperature sustained pressure testing that results in slit failures. These slit or SCG (slow crack growth) failures are the long-term failure mode for PE materials. A three-coefficient equation is then used to project performance at actual service temperatures and pressures. RPM testing is conducted not only with pressure as the primary load, but is also used to investigate secondary loads such as rock impingement, deflection, bending and squeeze-off. RPM testing was conducted on exhumed Aldyl “A” PE pipe. The RPM projected performance is correlated with actual field experience from two gas utilities for control pipe (primary load only), indented pipe (to simulate rock impingement) and squeezed pipe. This paper also correlates control, indented and squeezed RPM projections for exhumed Century PE pipe with its corresponding field experience from another gas utility.

Please note that the whole article content is available on PPCA website only :

Related papers

2021 Amsterdam : ALLOWABLE SCRATCH DEPTH HISTORY & RECOMMENDATIONS FOR PE PRESSURE PIPE

Author(s) : Chris Ampfer, Gene Palermo, Ernest & Oren Lever

This paper looks at the origin of the 10% allowable scratch depth rule for polyethylene (PE) pressure pipe developed in 1971 and research that has been performed over the years since its inception to determine the validity of this rule. The 10% rule has been used by natural gas pipeline operators since the 1970’s to...

2014 Chicago : Methodology to Determine Design Life of Assemblies of PE Pipe, Heat Fusion Fittings, and Heat Fusion Joints

Author(s) : Dr. Gene Palermo, Dr. Dane Chang, Dr. Jimmy Zhou

The scope of this paper is to provide information for the plastic piping industry on a test methodology that could determine the design life of heat fusion fittings and joints at the end user field conditions of operating stress, operating temperature and desired design life. This methodology is useful not only for...

2010 Vancouver : Changes to CSA Z662 “oil and gas pipeline systems” to incorporate higher performance plastic pipe

Author(s) : Rob. J. Fox, Dr. Gene Palermo

CSA Z662 is the Standard for the use of plastic pipe in Canadian oil and gas pipeline systems. This paper will give an overview of the recently approved revisions to CSA Z662-11 “Oil and Gas Pipeline Systems”, which will be published next year. These revisions include the following : - RCP Requirements for PE pipe, -...

2010 Vancouver : Comparison Between PE4710 (PE4710 PLUS) and PE100 (PE100+, PE 100 RC)

Author(s) : Dr. Gene Palermo

The scope of this paper is to clarify the various pipe material designation codes and other terms ( PE 4710, PE 4710 PLUS, PE 100, PE 100 RC and PE 100+ ) that are used in the piping industry for high density polyethylene (HDPE) materials. These are the benchmark “high performance” HDPE materials used worldwide for...

2010 Vancouver : Use of PE 100 with a minimum required strength (MRS) and categorized required strength (CRS) rating in a natural gas distribution system

Author(s) : G.Palermo

Manitoba Hydro is the electrical and natural gas utility for the province of Manitoba. A project to expand the existing natural gas system was initiated in 2005 which required the installation of a 29 kilometer (18 miles) main to connect a new town to the existing system. Project financial restrictions could not be...

2006 Washington DC : Innovative Methodology for Fitting Lifetime Prediction and Process Control

Author(s) : Lever, Palermo, Wright, Oliphant

The piping industry has a need for a well-founded methodology to predict lifetime of pipeline components subject to stress concentration. Another useful tool would be a method to assess the impact of manufacturing processes on the slow crack growth (SCG) properties of a resin that can be used for process control in a...

2006 Washington DC : Introducing PE100 for Medium Pressure Gas Networks in South America

Author(s) : Belforte, Gerard, Palermo, Guerra

South America is a region with a fast increase in economic growth and energy needs, and natural gas represents a strategic energy source not only for producers like Argentina but also for net importers like Uruguay and source-differentiated countries like Brazil. The fast development of the economy leads to request of...

2006 Washington DC : New Test Method to Determine Effect of Recycled Materials on Corrugated HDPE Pipe Performance as Projected by the Rate Process Method

Author(s) : Palermo, Vibien, Oliphant, Kosari

The corrugated HDPE pipe industry is considering the responsible use of recycled materials in their pipe production and also in their pipe standards. One of the key requirements for successful use of recycled materials is ensuring performance of the resulting HDPE corrugated pipe. As slow crack growth (SCG) has been...

2006 Washington DC : Using the CRS Concept for Plastic Pipe Design Applications

Author(s) : Palermo

The CRS (Categorized Required Strength) concept was developed within the ISO pressure rating system to provide more flexibility to the design engineer. One of the major uses of CRS is to provide a design basis of 100 years for plastic piping applications. With the CRS concept plastic pipe can now have a design basis...

2004 Milan : Can ISO MRS and ASTM HDB Rated Materials be Harmonized

Author(s) : Zhou, Palermo

ISO MRS and ASTM HDB rating systems have been successfully used for more than four decades in Europe and North America. MRS differentiates well the three generations of HDPE materials by classifying them as PE63, PE80 and PE100. However, HDB classifies all three generations of HDPE as only one PE 3408. When...

2001 Munich : Complex Yield Behaviour of PE100 Resin on Plane Strain Tensile Specimen

Author(s) : Choi, Lee, Broutman, Edwards, Palermo, Cho, Choi, Park

In recently designated plane strain grooved tensile (PSGT) methodology of ASTM F2018 standard, a groove in the direction perpendicular to the loading axis allows biaxial stress state to be generated under a uniaxial loading. The biaxial stress state produced very closely approximates the internally pressurized pipes...

2001 Munich : PPI Adopts International Pressure Rating Method for Plastic Piping Materials

Author(s) : Palermo

In addition to the HDB (Hydrostatic Design Basis) pressure rating obtained using ASTM D 2837, PPI (Plastics Pipe Institute Inc.) now also lists the MRS (Minimum Required Strength) pressure rating obtained with ISO 9080 in PPI’s publication TR-4, “Hydrostatic Design Bases (HDB), Pressure Design Bases (PDB), Strength...

1998 Gothenburg : An Alternate Method for Determining the Hydrostatic Design Basis for Plastic Piping Materials

Author(s) : Broutman, Edwards, Shah, Palermo

The Alternate Methods Committee of the Plastics Pipe Institute's Hydrostatic Stress Board (HSB) has initiated development of an alternate method for determining the hydrostatic design basis (HDB) for plastic piping materials. After reviewing several test methods, the plane-strain tensile method, developed by Choi and...

Increasing Importance of Rapid Crack Propagation for Gas

Author(s) : Palermo, Michie, Chang

Rate Process Method Applied to Service Life Forecast of PE Molded Fittings

Author(s) : Palermo

Members of the Association

BOREALISBOROUGEFormosa Plastics CorporationHanwha TotalEnergiesINEOS O&PIRPCKorea Petrochemical IND. Co., LTD (KPIC)LyondellBasellORLEN UnipetrolPetroChina Dushanzi Petrochemical CompanyPRIME POLYMERSABICSCG Chemicals & Thai PolyethyleneSinopecTASNEE