Gunther, Sandstrum
# 2001 Munich
Washington Gas has been researching a number of innovative methods for the repair and replacement of older large diameter cast iron mains. We considered direct burial, rolldown, U Lining, PIM, and guided boring. The ideal replacement technique would allow for a fully rated (64 psi or 5 bar) system which would have a low installation cost, a minimum 50 year life, rapid and easy installation, and provide a safe, secure, all- fused system. Trenchless technology is very attractive due to the low cost and minimal disruption to our customers. We wanted to replace an older 24" cast iron pipe operating at 20 psi (1.4 bar) with an inserted 16" IPS plastic main rated for 64 psi. Washington Gas would require the following performance criteria : 1. The polyethylene (PE) pipe must be rated at 64 psi and yet have the maximum internal diameter. Thus high density Standard Dimension Ratio (SDR) 17 was chosen. 2. The PE pipe must have a very high resistance to slow crack growth because of the potential stresses and damage that would be inherent in insertion. 3. The pipe must have the highest resistance to rapid crack propagation since it would be unrestricted inside several sections of a 24" cast main. Furthermore, it would be possible to have dramatic swings in pipe temperature, and if the pipe were to be impacted with enough force to break through the casing rapid crack propagation (RCP) could, in theory, initiate. 4. Controlling the gas flow is also critical, therefore a 16" squeeze off tool was developed and tested by Mustang Manufacturing. Ideally, the PE pipe would have to be able to be squeezed to 100% shutoff with no damage or reduction in usable life. 5. Joining the PE pipe was also an important consideration. It was imperative to develop and test plastic-to-steel transition fittings as well as complying with the requirements of the Plastic Pipe Institute (PPI) universal procedure (PPI TR - 33/99). We selected a material that would meet all of these criteria and that is PE-100. It is impervious to RCP because it has a critical temperature of zero degrees Fahrenheit (-18 degrees Celsius), and has a slow crack growth resistance of over 2000 hours in the PENT test. PE-100 can withstand substantial backhoe hits and mechanically induced damage that would cause failures in other piping systems. The PE-100 material we chose was Phillips 8300 pipe made from Solvay TUB 121 resin. On August 21, 2000 Washington Gas installed the first 16" IPS PE-100 material in the United States. We will monitor its performance closely over the next 10 years.
Related papers
Author(s) : Steve Sandstrum, Chris Ziu
The market for high performance polypropylene (PP) piping systems in North America continues to evolve. Generally, PP piping systems have performed exceptionally well in a variety of challenging HVAC, industrial and plumbing applications. As a result, the engineering community in North America is embracing higher...
Author(s) : Steve Sandstrum, Stefan Dreckoetter, Zak Schultz
This paper provides a historical overview of the development of polypropylene (PP) for piping applications. The discussion includes a historical review of each step in the evolutionary trend for PP piping materials over the last 40 years and culminates with a focus on the most recent development in PP piping...
Author(s) : Steve Sandstrum, Stephen Boros
As the technical performance and reliability of polyethylene pipe systems have grown, so too has the range of application and the complexities for designing and sourcing the variety of components necessary for these projects. In today’s global market, major industrial and/or municipal investments such as raw water...
Author(s) : Sandstrum Steve
The term “hydroelectricity” conjures images of massive concrete dams and vast reservoirs that harness the power associated with moving water. More recently, however, technological advancements and environmental awareness have resulted in renewed interest in small-scale hydroelectric projects. These unique...
Author(s) : S.Sandstrum
Historically, the procedure for butt fusion joining of polyethylene (PE) pipe in the United States has been qualified on the basis of two fundamental tests that are widely recognized within the North American industry. These are the tensile impact (TI) test method found in ASTM F2634 and the bend-back or reverse-bend...
Author(s) : Jos Robeyns, Philippe Vanspeybroeck, Steve Sandstrum
ISO CD 29561 applies to glass fibre reinforced polyethylene pipes and fittings intended to be used for the conveyance of water under pressure for general purposes, as well as for the supply of drinking water. The pipeline may be buried, above ground, or outside buildings. The temperature of the medium to be...
Author(s) : S.Sandstrum
Historically, polyethylene (PE) gas pipe systems in the United States have operated at service conditions for which the likelihood of a failure due to a rapid crack propagation (RCP) event has been nearly non-existent. The exceptional safety record for PE piping systems in this critical application has resulted in a...
Author(s) : Sandstrum, McKinley
The market for high density polyethylene (HDPE) pipe continues to expand across a variety of end use applications. As this growth continues to accelerate, users within the market place have become more familiar with the traditional method of joining HDPE pipe, namely butt fusion, and have become more educated in the...
Author(s) : Steve D. Sandstrum, White G. Jee
Polyethylene pipe produced from resins meeting the criteria for the PE 100 designation were first introduced on an international scale in the late 1980’s. Since, that time these piping products have grown to become recognized as the international standard for longterm performance in the use of polyethylene pipe. The...
Author(s) : Sandstrum
The use of polyethylene pipe in potable water systems has grown considerably over the past thirty years on both a domestic (North America) and international (Global) basis. Factors driving this growth have included material improvements, standards development, expansion of innovative construction techniques and...
Author(s) : Sandstrum
Members of the Association
