Pipe choices

November 2009 » SPECIAL REPORT
Sorting through pipe materials, applications, and suppliers.
Bob Drake

Pipe is perhaps one of the oldest and most common products used in water infrastructure construction — potable water, wastewater, and stormwater. The amount of pipe of all types installed and, in some cases, ongoing failures caused by improper application or simply pipe reaching the end of its lifecycle, have spawned a highly competitive market, technology advancements, and a wide choice of materials and suppliers.

CE News presents this special report to help civil engineers begin sorting through all of the pipe choices they face when designing water projects. National associations representing the eight most commonly used types of pipe — concrete, corrugated steel, ductile iron, fiberglass, polyethylene, PVC, steel, and vitrified clay — provided responses to four questions. Their answers are presented below. In addition, major manufacturers of each type of pipe are listed with web addresses or phone numbers for reference. Contact manufacturers for information about product lines and manufacturing and distribution locations.
 


The inherent durability and strength of precast concrete pipe make it particularly useful for special installations, including deep fills and heavy loads.

Concrete pipe

Q: What applications and environments particularly favor the use of concrete pipe?

A: Any normal conditions for storm sewers and culverts favor the use of precast concrete pipe. The inherent durability and strength of precast concrete pipe make it particularly useful for special installations, including deep fills and heavy loads. Emerging technologies include liners for sanitary sewers as well as the use of precast concrete pipe for tunneling or for replacement of failed sewers and culverts.

Q: How have the performance and/or application of concrete pipe changed during the last five to 10 years?

A: The biggest change during the last few years is the advancement of the manufacturing of precast concrete pipe by more automated equipment. This has resulted in a better-made pipe with consistent quality. Additionally, precast concrete pipe joints have improved in recent years because of better gasket technology.

Q: How does concrete pipe contribute to a project’s green building, sustainable design, or LEED certification goals?

A: With a verified service life of 100 years, precast concrete pipe is the most durable and sustainable pipe for storm drainage and culvert projects. Precast concrete pipe will directly contribute to a project’s achieving LEED points through construction waste management, materials reuse, recycled content, and regional materials. There are also numerous LEED applications where precast concrete pipe can be used that will help a project maximize the number of LEED points available through its use as a material for sustainable sites, water efficiency, thermal comfort, and numerous other green applications when designing and building a sustainable project. Precast concrete pipe has also been used as earth tubes for heating and cooling of LEED projects that can attain LEED Innovation and Design credits. Precast concrete pipe can be used with little or no backfill material, which reduces select backfill material that is needed for a project. Precast concrete pipe uses recycled steel for its structural steel requirements and contains fly ash or slag material that reduces the amount of cement needed in the pipe, thereby using recycled material that would otherwise be sent to landfills. There have also been many examples of the reuse of precast concrete pipe because of its durability and inherent strength.

Q: What specific resources are available to help civil engineers?

A: The American Concrete Pipe Association (ACPA) offers numerous resources on its website, www.concrete-pipe.org. The ACPA offers a Design Manual, Concrete Pipe Handbook, design data, and software to assist in the design of precast concrete pipe. Also available is the newly revised Concrete Pipe and Box Culvert Installation Manual, as well as several research reports that engineers should review before selecting drainage pipe.

Concrete pipe manufacturers
American Concrete Pipe Company
www.americanconcretepipe.com

Americast
www.americastusa.com

Ameron International
www.ameron-intl.com

Cretex Concrete Products Midwest
www.cretexmidwest.com

Geneva Pipe
www.geneva-pipe.com

Hanson
www.hansonpipeandprecast.com

Independent Concrete Pipe Company
www.icpipe.com

Johnson Concrete Company
www.johnsoncmu.com

Oldcastle
www.oldcastle-precast.com

Rinker
www.rinkerpipe.com

Sherman-Dixie Concrete Industries
www.shermandixie.com

Vianini Pipe Inc.
www.vianinipipe.com

Information contributed by American Concrete Pipe Association (www.concrete-pipe.org).


Polymer-coated, aluminized Type II, and galvanizedcoated CSP can all be supplied in varying gages and used in a variety of fill heights and in many designs.

Corrugated steel pipe

Q: What applications and environments particularly favor the use of corrugated steel pipe (CSP)?

A: Applications favoring corrugate steel pipe (CSP) include culverts, storm sewers, underground detention systems, underground retention systems, bridges, erosion prevention, fish passages, foundation structures, power plant cooling water lines, utility conduits, vehicle and rail grade separations, containment rings and tanks, and pedestrian and animal underpasses and overpasses.

Q: How have the performance and/or application of CSP changed during the last five to 10 years?

A: New coatings — namely polymer-coated and aluminized Type 2 CSP — have come to the forefront. Field performance has proven that, when specified within the industry-recommended environmental conditions, galvanized-CSP can provide a service life up to 50 years, while polymer-coated and aluminized Type 2 CSP can provide a service life up to 100 years. Polymer-coated, aluminized Type II, and galvanized-coated CSP can all be supplied in varying gages and used in a variety of fill heights and in many designs.

Q: How does corrugated steel pipe contribute to a project’s green building or LEED certification goals?

A: Steel is North America’s No. 1 recycled material. The high recycled content of CSP can be certified to aid in earning LEED points in the “Materials & Resources Credit 4” category. And the pipe meets all AASHTO and ASTM prime pipe standards.

Steel building products contribute positively toward earning points under Credit 4.1 and Credit 4.2. The following is required by LEED Version 2.1: Credit 4.1 (1 point) "Use materials with recycled content such that the sum of post-consumer recycled content plus one-half of the post-industrial content constitutes at least 5% of the total value of the materials in the project." Credit 4.2 (1 point) "Use materials with recycled content such that the sum of post-consumer recycled content plus one-half of the post-industrial content constitutes at least 10% of the total value of the materials in the project." "The value of the recycled content portion of a material or furnishing shall be determined by dividing the weight of recycled content in the item by the total weight of all materials in the item, then multiplying the resulting percentage by the total value of the item." Since steel (the material) and steel (the building product) are the same, the value of the steel building product is directly multiplied by steel’s recycled content, or, Steel Recycled Content Value = (Value of Steel Product) (Post-Consumer Percent + 1/2 Post-Industrial Percent).

Steelmaking Process* Basic Oxygen Furnace Electric Arc Furnace
Total Recycled Content**  28.9% 82.8%
Recycle Content Value for LEED Certification    
Post-Consumer Content Value 22.3% 46.2%
Post-Industrial Content Value 6.1% 31.1%

* Source: Steel Recycling Institute (www.recycle-steel.org)
** Details add to less than total due to exclusion of "home scrap" for LEED purposes. Check the LEED website for most current data.

Q: What specific resources are available to help civil engineers?

The following resources are available on the National Corrugated Steel Pipe Association’s website, www.ncspa.org, or at http://realdealonsteel.com: Corrugated Steel Pipe Design Manual; Installation Manual; Life Cycle Cost Analysis; Underground Detention System Program; brochures; and fact sheets; calculators, charts, and tools.

Corrugated steel pipe manufacturers

Atlantic Industries Ltd.
www.atlanticindustries.us

Big R Manufacturing, LLC
www.bigrmfg.com

C & K Johnson Industries, Inc.
www.ckjohnsonind.com

CONTECH Construction Products Inc.
www.contech-cpi.com

Dub Ross Company
www.dubross.com

Edwards Culvert Company
740-694-5096

Hawaii Concrete Products, Inc.
808-682-5639

Huron Tank and Culvert
www.huronculvert.com

Illowa Culvert and Supply
www.illowaculvert.com

J&J Drainage Products Company
www.jjdrainage.com

Jennmar Specialty Products
www.jennmar.com

Jensen Bridge and Supply Company
www.jensenbridge.com

Johnston Fargo Culvert, Inc.
www.johnstonculvert.com

Lane Enterprises, Inc.
www.lane-enterprises.com

Metal Culverts, Inc.
www.metalculverts.com

Pacific Corrugated Pipe Company
www.pcpipe.com

Roscoe Culvert
www.roscoeculvert.com

Southeast Culvert, Inc.
www.southeastculvert.com

St. Regis Culvert
www.stregisculvert.com

Thompson Culvert Company
314-731-4242

Wyatt Resources, Inc.
www.wyattresources.com

Information contributed by National Corrugated Steel Pipe Association (www.ncspa.org).


Polyethylene encasement on the spigot end of this DIP will be extended to cover the pipe and protect it from potentially aggressive soils.

Ductile iron pipe

Q: What applications and environments particularly favor the use of ductile iron pipe (DIP)?

A: Ductile iron pipe has been used for decades in water and wastewater pipeline applications: distribution and transmission service for water; collection, interceptor, and force main applications for domestic sanitary sewage; and plant process piping in water and wastewater treatment plants. Ductile iron pipe’s primary advantage is its strength. This allows designs to be achieved with a high degree of conservatism, which gives confidence that actual field conditions will not exceed design limits. It also makes ductile iron pipe a favorite in more difficult installations, such as for high internal pressures, deep bury, and any applications requiring a robust product.

In installation, the nature of the push-on joint allows for field adaptability. The joint is deflectable, affording the routing of ductile iron pipe along smooth curves and making abrupt changes in direction possible with standardized bends and tees. Plus, ductile iron pipe underground joints use gaskets that are installed in the bell, making it possible to cut the pipe in the field to accommodate conditions that may be encountered as the pipe is installed.

An emerging application in the last few years has been the use of ductile iron pipe in trenchless applications such as horizontal directional drilling (HDD). HDD involves drilling a small pilot hole using a drill that is tracked and steered from the surface. Ductile iron pipe’s restrained joints facilitate HDD installations. Advantages for ductile with HDD include great material strength for handling pull-back and external dead and live loading; better distribution of thrust or pulling forces around the bell and barrel; greater allowable pulling forces than other pipe options; generous allowable joint deflections; quick, easy joint assembly; “cartridge” installation option for limited easements or right-of-ways; located from surface with commonly used locators; performance capabilities are not impacted by elevated temperatures; material strength that does not creep or decrease with time; and no significant residual bending stresses remain in the pipe after the pull-back that could adversely affect future serviceability, including tapping.
 

Q: How have the performance and/or application of DIP changed during the last five to 10 years?

A: In 2004, a proprietary model for determining the need for and type of corrosion control was introduced. This model, known as the Design Decision Model evaluates the likelihood of corrosion in consideration of the consequences of a related problem. Featuring polyethylene encasement in accordance with the ANSI/AWWA C105/A21.5 standard, which has been used in water and wastewater systems for more than 50 years, the methods were developed in cooperation with Corrpro Companies, one of the world’s largest corrosion consulting firms. The recommendations found in this system are designed to allow the pipeline to serve for a minimum of 100 years.

In addition, while the standard cement-mortar lining provides improved long-lasting hydraulic attributes for water and most domestic sanitary sewage applications, special linings have also been developed to protect the pipe against exposure to septic sewage and other special internal applications.

Also, while the body of ductile iron pipe is impermeable, gasket materials have been introduced to ensure that contaminants that might have made their way into a proposed trench zone will not permeate into the pipeline and adversely affect the liquids being carried.

The introduction of restrained joints has allowed thrust restraint designs to eliminate thrust blocks and to initiate the installation of ductile iron pipe through trenchless methods such as HDD.

Q: How does DIP contribute to a project’s green building or LEED certification goals?

A: Ductile iron pipe manufactured in the United States is made of scrap iron and steel — wholly recycled raw materials. Depending on the size of the pipe and the nature of the lining being applied, the recycled content for ductile iron pipe can exceed 90 percent. Also, for a given nominal pipe size, ductile iron pipe typically has a larger inside diameter to go along with its smooth cement-mortar lined interior surface. Therefore, a given flow being pumped through ductile iron pipe experiences lower head losses and requires less consumption of energy over an operating service life.

Both of these criteria are being considered to apply to future LEED for Neighborhood Development designs that call for minimum new infrastructure recycled content and energy efficiency for water and wastewater piping.

Natural resource consumption is favorably low in the manufacture of ductile iron pipe. It is also a recyclable material that can be recovered, if need be, and used as a raw material for future pipe.

The iron industry has continued to recognize its responsibilities in the world. Ductile iron pipe is manufactured from 100-percent recycled scrap iron and steel, making it a responsible consumer of natural resources. The manufacturing process recycles process waters, minimizing water discharges which are treated on-site, reuses waste heat from production, and removes all contaminants from gas streams.

Additionally, ductile iron pipe’s strength allows backfills that utilize native soils, which minimizes the need for select materials to be transported to a job site and used in construction.

Finally, there is nothing more sustainable than a pipeline that can be reliably designed for 100 years of service.

Q: What specific resources are available to help civil engineers?

A: The Ductile Iron Pipe Research Association (DIPRA) maintains a library of technical brochures that provide great information related to pipe wall thickness design, corrosion control, thrust restraint design, hydraulic analysis, installation, and comparisons with other pipe materials. All of these publications are available as PDF downloads on DIPRA’s website, www.dipra.org. Also available are computer programs that help engineers calculate the required pipe wall thickness to carry internal and external loads, pipe-on-support design, restrained joint thrust restraint design, and the hydraulic analysis of pumping through ductile iron pipe as compared with other pipe materials.

Additionally, the American Water Works Association (AWWA, www.awwa.org) publishes manual M41 “Ductile Iron Pipe and Fittings” that addresses most standard and special application questions. Also, AWWA standards address manufacture, design, joints, fittings, corrosion control, and installation of ductile iron pipelines.

DIPRA also provides in-house technical services through its Regional Engineer Program, where professional engineers trained in pipe application can discuss applications issues directly with designers and specifiers.
 

Ductile iron pipe manufacturers

American Cast Iron Pipe Company, American Ductile Iron Pipe Division
www.acipco.com

Atlantic States Cast Iron Pipe Company
www.atlanticstates.com

CLOW Water Systems Co.
www.clowwater.com

Griffin Pipe Products Co.
www.griffinpipe.com

McWane Cast Iron Pipe Company
www.mcwane.com

Pacific States Cast Iron Pipe Company
www.pscipco.com

United States Pipe and Foundry Company
www.uspipe.com

Information contributed by Ductile Iron Pipe Research Association (www.dipra.org).


Using direct bury and tunneling, workers installed 4,000 feet of 48-inch-diameter HOBAS pipe in Salt Lake County, Utah, at depths from 2 to 26 feet.

Fiberglass pipe

Q: What applications and environments particularly favor the use of fiberglass pipe?

A: Fiberglass pipe is best suited for the following applications:

• Direct bury and aboveground applications in potable water transmission, force main or gravity sewer systems, and all applications where there is a corrosive carrier or external environment.

• Trenchless applications including sliplining, microtunneling, directional drilling, pipe jacking, pipe bursting, tunnel lining, and casings.

• Varied-length applications where sections are limited or where long sections will minimize the number of joints. The typical delivered length is 20 feet; however both short sections (for example, 5 feet or 10 feet) and longer lengths of up to 40 feet are used.

• Leak free joints where fiberglass pipe utilizes a number of gasket-sealed joints. Typically, the pipe joints are push-together coupling or bell-spigot joints. Restrained joints are available from some manufacturers for curved or otherwise stressed pipe sections.

• Large diameters where the pipe is available from 18 to 158 inches in diameter, depending on the manufacturer.

• Long 50-year design life which impacts life-cycle cost evaluations. Fiberglass piping has a more than 40-year history, both worldwide and in the United States. In addition, there is a 20-year U.S. history specific to the municipal sector. While the total installed footage is not known, there has been more than 5 million feet of large-diameter pipe installed to date by Hobas Pipe, USA. Many cities have used fiberglass exclusively in recent large-diameter sewer rehabilitation programs. For example, fiberglass now makes up more than 15 percent of the greater-than-48-inch-diameter piping in the city of Houston.

• Engineering standards including ASTM D3262 for gravity systems and AWWA C950 for pressure applications.

• Wide range of service conditions including extreme cold, which does not affect the material. The pipe can be manufactured for operating temperatures up to 180° F. and pressures up to 250 pounds per square inch. The pipe is extremely repairable and easy to modify in the field should conditions warrant. In addition, the pipe is extremely abrasion resistant.

• Specific applications where each pipe is designed for soil burden, external water pressure and live loading conditions.

• High-flow characteristics where hydraulic analysis shows superb flow characteristics — Manning’s n = 0.009 and Hazen Williams C = 155.

• Emerging applications include the capability to design and manufacture elliptical and other non-round fiberglass pipe for sliplining, tunnel lining, and casings where the previous carrier pipe was not round in shape.

In summary, fiberglass pipe has universal applications with leak-free joints, inherent corrosion resistance, superior low-friction hydraulic characteristics, and long life service. While cost savings accrue from using smaller-diameter, high-flow-rate pipe, there are also installation savings from reduced transportation and onsite handling costs (high strength/ weight-ratio pipe) and reduced labor and installation time (longer pipe with fewer joints). Fiberglass pipe is an engineered product that may be custom manufactured with fiberglass manways and fittings to meet the most difficult job site applications.

Q: How have the performance and/or application of fiberglass pipe changed during the last five to 10 years?

A: Design engineers are gaining knowledge and experience with fiberglass pipe material rather than relying on standard civil engineering curriculums that typically address traditional piping materials. Municipal and consulting engineers are gaining on-the-job exposure to and experience with new marketplace materials such as fiberglass piping. This is making a major impact in many market areas, including the large-diameter municipal piping sector. For example, nine out of 10 of ENR’s top 500 design firms are specifying fiberglass piping for the municipal market. In addition, more than 70 million feet of underground fiberglass piping has been installed in petroleum service, including crude oil production fields and most retail service stations.

From a life-cycle cost approach, fiberglass piping has been found to be the lowest cost, long-term alternative for many applications. Fiberglass piping exhibits long life in septic sewers; long-term high-flow rate hydraulics due to its non-porous interior wall; high-strength, leak-free joints; and oversized diameters, all of which contribute to the lowest long-term cost, even though in some cases, a slight premium may be paid for the initial product.

Q: How does fiberglass pipe contribute to a project’s green building or LEED certification goals?

A: Fiberglass pipe manufacturers have joined with underground fiberglass tank designers to develop large-capacity community septic systems in remote locations without sewage treatment systems, and large-capacity underground fiberglass tank rainwater harvesting/storage and stormwater runoff retention systems. These systems capture and reuse groundwater resources that meet LEED certification goals.

Q: What specific resources are available to help civil engineers?

A: Two handbooks for engineers address design and installation of municipal fiberglass pipe. AWWA M45 - Fiberglass Pipe Design addresses design. The second handbook and video, “Design and Installation of Buried Pipe,” provides installation contractors with proper fiberglass pipe installation and burial methods. It is published by the American Society of Civil Engineers under its Continuing Education program and cosponsored by the Institute.

The Institute website (www.fiberglasstankandpipe.com) offers links with fiberglass pipe manufacturers that will provide job lists detailing the projects installed to date and published technical information describing their products. Fiberglass pipe manufacturers also offer guide specifications to aid engineers that may not have experience with their products. Institute fiberglass pipe manufacturers also offer field service representatives to work onsite with new installation contractors to be sure proper installation methods are followed.

The Institute administered a three-year University of Houston (UH) research project that simplifies life cycle cost calculations. An interactive Life Cycle Model that includes default settings based on an international literature search is published on the UH website at www2.egr.uh.edu/~civeb1/CIGMAT/research.htm#ClayPipe.
 

Fiberglass pipe manufacturers

Ameron Fiberglass-Composite Pipe Group/USA
www.ameron-fpg.com

Ameron Municipal Fiberglass Pipe
www.ameronbondstrandrpmp.com

Future Pipe Industries, Inc.
www.futurepipe.com/usa

Hobas Pipe USA
www.hobaspipe.com

U.S. Composite Pipe Co.
www.uscompositepipe.com

Information contributed by Fiberglass Tank & Pipe Institute (www.fiberglasstankandpipe.com).


The stormwater detention system installed under a parking lot uses 48-inch-diameter corrugated highdensity polyethylene (HDPE) pipe.

Polyethylene pipe

Q: What applications and environments particularly favor the use of polyethylene (PE) pipe?

A: Highly acidic or alkaline soils and flows do not attack polyethylene (PE) pipe and thus it is routinely specified in these harsh conditions and services. In systems where exfiltration of flow (water, sanitary sewer, and gas) or infiltration of leachate or soils (water, stormwater) is strictly forbidden, PE pipe systems, with their leak-free and water-tight joints, have proven to be a most economical choice.
Although PE pipe is routinely installed using open-cut (trench) methods, the flexibility and monolithic pipe string of fused PE pipe (or long coil lengths of smaller diameters) does not require joint constraints, making it a natural choice for trenchless installation practices including horizontal directional drilling, sliplining, and pipe bursting. Lastly, the relatively longer lengths of PE pipe (20 to 50 feet) compared with traditional pipe materials lowers installation times (and cost) while reducing the number of joints per run of pipe, further decreasing potential joint problems.

PE pipe is the only material routinely specified and used in every utility service including natural gas distribution, potable water distribution, sanitary and forced sewer, stormwater management, electrical and communication conduit, hot and cold water service lines, geothermal heating and cooling, and subsurface drainage. Other applications include oil and gas production, methane and leachate collection (landfill), radiant heating, industrial, and mining slurries and flows.

Most recently, PE pipe has been tested, evaluated, and put to work in several nuclear power plants in safety- and non-safety-related service water systems. Working with the American Society of Mechanical Engineers, the development of a Code Case was recently completed which has instructions for PE pipe including how the pipe is to be supplied, design parameters, installation rules, fusion joining requirements, and pressure test criteria.

One of the driving reasons for the acceptance of PE pipe was the corrosion and fouling (from tuberculation) of carbon and stainless steel pipe systems. The other driver was the cost of installing these lines. Today, 400 feet of PE pipe can be installed per day compared with 40 to 60 feet for steel lines at a cost one-fifth that of steel. This significant cost reduction has allowed the plants to now install redundant systems, making the plants safer.

In the past few months, the Nuclear Energy Institute bestowed its Top Industry Practice Award to the Catawba nuclear station in South Carolina and the Callaway nuclear plant in Missouri, recognizing their innovations in replacement of carbon steel pipe with PE. These developments have established a new standard within the nuclear industry.

Q: How have the performance and/or application of PE pipe changed during the last five to 10 years?

A: During the last decade, the introduction of high-performing PE resins (PE 3608 and PE4710) has allowed pipe systems to operate at a higher design stress without sacrificing safety or service life. Along with improvements in manufacturing capabilities allowing diameters as large as 63 inches, new opportunities have been opened in pressure systems where only traditional materials (steel) had been used before.

In gravity flow systems, continued development of profile designs and the introduction of larger diameters have further increased the applicability of PE pipes in stormwater systems. Burial depths in excess of 100 feet and diameters as large as 60 inches give design engineers more options to incorporate corrugated PE pipe’s inherent physical properties in providing longer lasting and sustainable underground infrastructure solutions.

Further advances through the use of composites, incorporating either other plastics or non-plastics, will increase the use of plastic pipe in the future.

Q: How does PE pipe contribute to a project’s green building or LEED certification goals?

A: PE pipe provides a sustainable solution whose performance has been validated for more than 50 years. Starting with a leak-free joint for pressure systems, or a watertight joint in gravity flow applications, PE pipe is the green choice for municipal water, sewer, and stormwater applications. A lower carbon footprint is the hallmark for PE pipe, starting with its low energy requirements for manufacturing. Continuing through transportation and installation, the energy needed to completely install a PE pipe system pales in comparison with the economic and carbon costs of pipe made from metal or concrete. And with PE pipe’s resistance to corrosion and abrasion it will last for generations to come. This translates to direct savings to the consumer and the environment.

PE pressure pipe systems have a zero leak rate because of a heat fusion process that produces a monolithic pipe string. That not only means natural resources are saved but the energy to treat and pump water is conserved as well.

In municipal storm sewer systems, improvements in joint design have delivered measurable benefits. Today’s corrugated PE pipe comes with a factory-installed rubber gasket providing an exceptional soil-tight joint. For increased performance levels, the bells and gaskets can be easily modified to deliver water-tight performance — to the same level required for sanitary sewer systems. And with pipe lengths of 20 feet, PE stormwater pipe systems need just about one-third the number of joints as compared with concrete pipe systems.

PE water pipe is not subjected to galvanic corrosion and is resistant to tuberculation of dissolved minerals. That means it doesn’t rust, the water won’t be discolored, and it doesn’t lose its long-term hydraulic efficiency caused by buildup.

Stormwater systems are also subjected to harsh chemicals and aggressive flow conditions. Corrugated PE pipe is unaffected by roadway salts, brackish water, roadway pollutants, and corrosive flows and “hot” soils. A superior joint limits infiltration and exfiltration that can prematurely end a system’s design life. And lastly, abrasion resistance can deliver an exceptional service life.

Designers can take advantage of PE pipe in geothermal heating and cooling systems that can reduce energy consumption as much as 50 percent; in gray water systems that reuse a significant amount (50-percent-plus) of a building’s wastewater onsite; in solar hot water collection systems as preheating for the incoming water; and in rainwater harvesting to conserve potable water.

Crosslinked PE (PEX) pipe is widely used for heat-transfer applications — both low-temperature (radiant floor heating, snow melting, and ice rinks) and distribution piping for temperatures as great as 200° F for hot water baseboard, convectors, and radiators. PEX pipe is also approved for fire sprinkler systems according to NFPA 13D.

Q: What specific resources are available to help civil engineers?

A: For more than 50 years, the Plastics Pipe Institute, by itself and in conjunction with other national standard organizations and associations, has provided extensive information on applications and uses for PE pipe. Its website includes all of its documents (available for free downloading), including model specifications and design guidance (http://plasticpipe.org/general/general_publications.php).

The PPI Handbook of Polyethylene Pipe and the Corrugated Polyethylene Pipe Design Manual are available on the website and can also be downloaded for free. The PPI Handbook of Polyethylene Pipe is also available as a printed hardback book and is available for purchase at: www.plasticpipe.org/general/ppi_handbook.php.

Other pertinent publications the PPI has contributed to are AWWA M55 - PE Pipe Design and Installation; American Gas Association Plastic Pipe Manual; and Residential PEX Water Supply Plumbing Systems Design Guide.
 

Polyethylene pipe manufacturers  

Advanced Drainage Systems. Inc.
www.ads-pipe.com

A-D Technologies
www.adtechnologies.com

Aquatherm
www.aquatherm.de

Baughman Tile Company, Inc.
www.baughmantile.com

Blue Diamond Industries
www.bdiky.com

Bow Plastics
http://bow-group.com

Charter Plastics, Inc.
www.charterplastics.com

Chevron Phillips Chemical Company, Performance Pipe
www.cpchem.com/enu/performance_pipe.asp

CONTECH Construction Products Inc.
www.contech-cpi.com

Crumpler Plastic Pipe
www.cpp-pipe.com

Endot Industries Inc.
www.endot.com

Flying W Plastics, Inc.
www.flyingwplastics.com

Fratco/Francesville Drain Tile Corp.
www.fratco.com

Hancor, Inc.
www.hancor.com

High Country Fusion
www.hcfusion.com

Ideal Pipe
www.idealpipe.ca

Independent Pipe Products Inc.
http://independentpipeproducts.com

Industrial Pipe Fittings, LLC
www.hdpefittings.com

IPEX Inc.
www.ipexamerica.com

JM Eagle
www.jmeagle.com

KWH Pipe Ltd.
www.kwhpipe.ca 

Lamson Pipe
www.lamsonpipe.com

Lane Enterprises Inc.
www.lane-enterprises.com

Mercury Plastics
www.mercuryplastics.com

National Pipe & Plastics, Inc.
www.nationalpipe.com

NIBCO
www.nibco.com/cms.do

Pacific Corrugated Pipe
www.pcpipe.com

Plastic Tubing Industries
www.ptifla.com

PolyPipe, Inc.
www.polypipeinc.com

Prinsco, Inc.
www.prinsco.com

Quality Culvert
www.qualityculvert.com

REHAU, Inc.
http://na.rehau.com

Soleno, Inc.
www.soleno.com

Southeast Culvert
www.southeastculvert.com

Springfield Plastics, Inc.
www.spipipe.com

TIMEWELL
www.timewellpipe.com

Uponor
www.uponor-usa.com

Viega NA
www.viega.net

Watts Canada
www.wattscanada.ca

Watts USA
www.watts.com

WL Plastics
www.wlplastics.com

Zurn Industries
www.zurn.com

Information contributed by Plastics Pipe Institute, Inc. (www.plasticpipe.org).


PVC pipe, such as this 36-inch ASTM F679 PVC gravity sewer pipe being installed in Frisco, Texas, is compatible with any natural soil condition and does not require corrosion protection.

PVC pipe

Q: What applications and environments particularly favor the use of PVC pipe?

A: PVC is today’s most widely utilized pipe material in the United States and Canada for transporting fluids. PVC pipes’ combination of outstanding performance and value for more than five decades has resulted in their holding majority shares of both the new sanitary sewer and new water distribution pipe markets in the United States and Canada. Owner and contractor familiarity with PVC pipe is well established. PVC pipes are also often used for sewer force mains, agricultural and turf irrigation piping, stormwater drainage, and a variety of industrial piping applications. Emerging applications for which PVC pipes are well suited include reclaimed/recycled water systems, trenchless directional drilled installations, and pipeline rehabilitation.

PVC pipes offer great advantage in environments that are corrosive to metals and metal-reinforced pipe. Since PVC is a non-conductor, both galvanic and electrochemical effects are non-existent in PVC pipe and fittings. PVC suffers no damage from attack of normal or corrosive soils and is not affected by sulfuric acid in the concentrations found in sanitary sewer systems. As a result, no linings, coatings, or cathodic protection are required when PVC pipe is used.

Since PVC pipe does not corrode, there is no tuberculation caused by corrosion by-products. No tuberculation means that there is no reduction in flow areas and flow coefficients as PVC piping systems age. The long-term result of PVC pipe’s resistance to tuberculation is reduced costs for operations and maintenance. PVC pipes are hydraulically smooth and leak-free.

PVC offers much higher tensile strength than other thermoplastic pipe materials. PVC has superior stiffness (modulus) compared with other thermoplastic pipes, which enables PVC pipe to better resist buckling and limit long-term deformation under soil load. PVC resists hydrocarbon permeation better than other thermoplastic pipes (AWWA Research Foundation) and PVC is more resistant to water disinfectant-induced oxidation than other common thermoplastic pipes.

Q: How have the performance and/or application of PVC pipe changed during the last five to 10 years?

A: Technology improvements in manufacturing controls and testing techniques enable manufacturers to produce a consistent product of higher quality. The demand for larger-diameter PVC pipes and fittings (as large as 48 inches for pressure pipe and 60 inches for gravity pipelines) has grown most rapidly during the last 10 years.

New and innovative restrained joining technologies have enabled PVC pipe to become a major and often preferred option for trenchless installation projects such as horizontal directional drilling, sliplining old or damaged pipes, and pipe bursting. Applications for this technology cover every aspect of piping installations including both pressure and non-pressure situations in the water, sewer, electrical, industrial, and telecommunications industries.

PVC pipe design technology has also been advanced within the last 10 years. Wide-ranging testing and research in the area of cyclic pressure performance of PVC pipe has been completed. U.S. and Canadian manufactured PVC pipes were tested under a variety of pressure surge situations through millions of pressure cycles to establish conservative performance boundaries for PVC pressure pipe. This comprehensive evaluation of PVC pipes by researchers at Utah State University enabled them to develop a cyclic pressure design approach that has been incorporated in PVC pipe standards AWWA C900 and AWWA C905.

PVC pipe strain testing was also reported within the last 10 years. Knowledge of a plastic pipe material’s capacity to endure long-term strain without cracking is important for proper design and performance. Pipe bending and ring deflection produce strain in a pipe material. Professor Al Moser of Utah State University evaluated the PVC pipes for longer than 22 years. PVC pipe test specimens were strained in a range of 1.0 to 95 percent. Each specimen was pulled to a predetermined strain. Some specimens were notched. Notching the samples intensified the strain. Intensified strain in combination with maintaining a lower temperature combined to accelerate brittle fracture, if it is going to occur. The specimens were placed in a freezer at 0° F. After 22 years under test, Moser reported that no failures occurred, even in the notched specimens. The tests demonstrated that under a constant strain condition, if the initial strain can be achieved, failure will not occur in PVC pipe. Additionally, PVC pipes, manufactured from compounds of cell classes 12364 and 12454 in accordance with ASTM D1784, do not lose stiffness with time.

More recent independent research into the ability of PVC pipe to prevent contamination via permeation in environments contaminated by petrochemical solvents and chemicals was funded by the Water Research Foundation (formerly AwwaRF) and conducted at Iowa State University. Researchers concluded that PVC itself is impervious to gasoline, BTEX, and trichloroethylene (TCE) in groundwater at commonly encountered levels of contamination.

Considering the extensive and widespread use of PVC pipe by the drinking water industry, the Water Research Foundation and the Australian Commonwealth Scientific and Industrial Research Organization (CSIRO) co-funded a research project to evaluate the long-term performance of PVC water pipes that was published in 2007. Researchers carefully analyzed 40-plus years of available in-service pipe performance information. Their model projects that water utilities can expect a minimum service life of 100 years from PVC pipe when properly designed and installed. From the relatively low failure rates that the researchers project for PVC pipes in service for as long as 110 years, PVC pipe is arguably a best-practice option for achieving sustainable water distribution/transmission systems.

Q: How does PVC pipe contribute to a project’s green building or LEED certification goals?

A: As issues regarding environmental protection and sustainability have moved higher on public and political agendas, the demand for PVC pipe has also risen. Indeed, the PVC pipe industry owes much of its success to environmentalists and the environmental movement. More importantly, our environment has benefited immensely as a result of the widespread use of PVC pipe.

For a pipe to be considered sustainable it needs to be produced with minimal environmental and carbon footprint, exhibit as small of a life cycle cost as possible, be maintenance-free or require minimal maintenance, and be able to be recycled at the end of its useful life.

An Australian (CSIRO) study compared the embodied energy of various pipe products and concluded that, “Within all scenarios, virtually all the various forms of PVC pipes produced lower embodied energy results than any other piping material.” Embodied energy is defined as “the quantity of energy required by all of the activities associated with a production process, including the relative proportions consumed in all activities upstream to the acquisition of natural resources and the share of energy used in making equipment and in other supporting functions, i.e., direct energy plus indirect energy.” The study considered the energy required to manufacture the raw materials, transport of the raw materials, the pipe manufacturing process, as well as the embodied energy implications of using different piping solutions to achieve a similar hydraulic performance over a fixed length. The latter is important because thermoplastic pipes are more flow efficient as a result of their smoother interior surfaces.

Thus, PVC pipe use lowers carbon dioxide emissions that contribute to global warming. PVC pipes are generally easier to cut in the field and can be joined to standard appurtenances (valves, fittings, hydrants, etc.) without the need for special connections or adaptor couplings. Properly assembled PVC pipe joints are leak-free and PVC pipe’s strain ability resists cracking. By and large, PVC pipes also require little or no maintenance when designed and installed correctly.

PVC pipes are not reactive with water and consequently do not adversely change water quality. Chlorinated drinking water has no appreciable oxidizing affect on PVC pipe. Non-plasticized PVC pipe has the added advantage of providing the greatest resistance to biological growth of all common water and wastewater pipe materials. While there are some chemical solvents that can alter or attack PVC pipe, the concentrations required to do so are much higher than those normally encountered in pipeline installations.

Furthermore, PVC is produced by combining ethylene (derived from either natural gas or petroleum) and chloride from salt (sodium chloride). As a result only 43 percent of PVC comes from a non-renewable resource in the form of fossil fuels. PVC pipes can also be recycled and only require a small fraction of the energy necessary to recycle pipes comprised of metal or concrete.

Q: What specific resources are available to help civil engineers?

A: The Uni-Bell PVC Pipe Association’s website provides access to available technical information, software, and its comprehensive Handbook of PVC Pipe – Design and Construction.

PVC pipe manufacturers

CertainTeed Corporation
www.certainteed.com/products/pipe

CONTECH Construction Products Inc.
www.contech-cpi.com

Diamond Plastics Corporation
www.dpcpipe.com

IPEX Inc.
www.ipexamerica.com

JM Eagle
www.jmeagle.com

National Pipe & Plastics, Inc.
www.nationalpipe.com

North American Pipe Corporation
www.northamericanpipe.com

Northern Pipe Product Inc.
www.northernpipe.com

Pipelife Jet Stream, Inc.
www.pipelife-jetstream.com

Information contributed by Uni-Bell PVC Pipe Association (www.uni-bell.org).


Steel pipe can be configured with various joint types, and can be fabricated into elbows of any angle, reducers, wyes, crosses, and tees.

Steel pipe

Q: What applications and environments particularly favor the use of steel pipe?

A: In the water industry, welded steel is a particularly favored material for potable water pipe systems of 30 inches diameter and larger. It is adaptable for high internal pressure applications, a direct result of the availability of a wide selection of steel yield and tensile strengths.

Steel pipe has the benefit of being the most versatile pipe material available. It can be configured with various joint types, and can be fabricated into elbows of any angle, reducers, wyes, crosses, and tees.

Steel pipe is used to transport a potpourri of fluids long distances, and with the application of any number of high-quality coatings, is adaptable through all types of soil environments as well as exposed piping systems.

Steel pipe is used for many other liquid transport applications, such as for energy distribution at power plants and for the oil industry. It has also become an important part of wind energy, as thousands of steel towers are installed to supports the wind turbines.

Q: How have the performance and/or application of steel/welded steel pipe changed during the last five to 10 years?

A: The availability of high-quality coatings further expands the corrosion protection options available t


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