The Impact of Heavy Hydrocarbon Permeation on PE Pipe

Papers # 2014 Chicago

DOT/PHMSA held a Government/Industry Pipeline R&D Forum on July 18-19, 2012. Five working groups met to discuss key pipeline technical challenges facing industry and government. The Design/Materials/Welding-Joining & Valves working group identified the effects of hydrocarbon permeation on plastic pipe strength and fusion performance as a gap that needs to be addressed. There is mounting evidence in certain regions that PE gas distribution pipelines are being exposed to hydrocarbon contamination. Because PE is nonpolar, it is a very poor barrier to nonpolar hydrocarbons as might be found in the natural gas industry. In the case of liquid permeation, the diffusion phenomenon occurs in areas of gross contamination when liquid hydrocarbon condensates form in gas pipelines, or when soil surrounding the pipe is heavily contaminated with liquid hydrocarbons (diesel, gasoline, etc.). The presence of these hydrocarbons in the plastic matrix can have a negative influence on two important aspects associated with gas operations: thermal fusion quality and pipe strength. The magnitude of the impact depends on the amount of contamination. The most common issue is that heat joining techniques on hydrocarbon permeated pipes may result in lower strength joints. Because the source of contamination can be both internal and external, it can affect any type of saddle and butt fusions. If the pipe wall is weakened, it may require derating. Also of interest is the impact of impregnated hydrocarbons on slow crack growth (SCG). It is not understood whether the presence of hydrocarbons inhibits or accelerates SCG. This paper will provide an update on the status of the two year research project that GTI has undertaken to quantify the effects of hydrocarbon contamination on PE pipe. Current results will be presented and discussed at the conference presentation.

Related keywords : hydrocarbon, pipe, gas, impact, data, strength, industry.
Please note that the whole article content is available on PPCA website onlySource : 2014 Chicago


Related papers

DEVELOPMENT OF CYCLIC PRESSURE FATIGUE (CPF) TEST METHOD

Author(s) : Ernest Lever 2018 Las-Vegas

Six different polyethylene materials were tested using Cyclic Pressure Fatigue (CPF) as the accelerating process to correlate the results to conventional long-term hydrostatic test results that were previously developed as part of the material qualification process. The designation of the materials was unknown to the...

PE4710 MITERED ELBOW DESIGN JUSTIFICATION BY FINITE ELEMENT ANALYSIS

Author(s) : Gerry Groen, Ernest Lever, Oren Lever 2016 Berlin

A design justification for reinforcement of fabricated Polyethylene elbows is presented. The acceptance criteria is that the average stress in the mitered wall of fabricated elbow shall not exceed the hoop stress in the matching pipe. ASTM and ISO standards have established requirements for the geometry, production...

Reducing operational risk in vintage plastic distribution systems

Author(s) : Ernest Lever, Yongming Liu, Yiming Deng 2016 Berlin

This collaborative program will provide an integrated set of quantitative tools that will provide a structured approach to reducing operational risk in vintage plastic distribution systems susceptible to Slow Crack Growth failures. A novel endoscopic structured light scanning tool will be developed and prototyped for...

THE EFFECTS OF HEAVY HYDROCARBON PERMEATION ON POLYETHYLENE PIPE

Author(s) : Ernest Lever, Karen Crippen 2016 Berlin

The objective of this project was to develop methods to be used by any plastic testing laboratory to quantify the effects of hydrocarbon permeation on: 1) the fusibility of plastic pipe; 2) the life expectancy of existing fused joints that have been subjected to hydrocarbon permeation; 3) the Hydrostatic Design Basis...

An Evaluation of Aged MDPE Gas Pipes

Author(s) : Karen S. Lively, Pamela L. Maeger 2014 Chicago

Medium Density Polyethylene (PE80/PE2708 type) pipelines have been used globally in natural gas service applications for over 50 years. The condition of existing pipelines is critical to assessing existing infrastructures for utility operators and various regulatory bodies. This paper includes a review of the...

Bi-Directional Shift Factors Revisited

Author(s) : Ernest Lever 2014 Chicago

The Popelar bidirectional shift factors have been now been used about a quarter century to great effect. The question has been raised as to whether the shift factors are applicable to modern materials. GTI has been using rheological principles and Dynamic Thermo Mechanical Analysis (DTMA) to routinely develop...

Remaining Life Expectancy and Risk Profile of Vintage Aldyl A Piping

Author(s) : Ernest Lever 2014 Chicago

Aldyl A piping systems are closing in on fifty years of service in North America. Several North American gas utilities are assessing the remaining lifetime expectancy of their Aldyl A piping systems and preparing replacement programs. GTI has been actively involved in multiple research efforts related to Aldyl A...

Innovative Methodology for Fitting Lifetime Prediction and Process Control

Author(s) : Lever, Palermo, Wright, Oliphant 2006 Washington DC

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...

Design and Pressure Rating of PE Fittings, Stress Concentrations, Slow Crack Growth and the USE of ISO9080

Author(s) : Lever 2004 Milan

It has long been established that the primary long-term failure mode of PE fittings is Slow Crack Growth (SCG) from the area of highest stress concentration. This area of highest stress concentration is usually situated at the edge of the fusion joint, be it a conventional socket, sidewall or electrofusion joint....

Members of the Association

BOREALISBOROUGEINEOS O&PIRPCKorea Petrochemical IND. Co., LTDLyondellBasellPetroChina Dushanzi Petrochemical CompanyPRIME POLYMERSABICSCG Chemicals & Thai PolyethyleneSinopecTASNEE
TOP