There are many different types from which to choose, all exhibiting certain characteristics that can make it the ideal choice for specific needs.

To help planners decide which type of pipe is best for their particular purposes, Trenchless Australasia is pleased to be able to bring readers a comprehensive overview of the pipes most commonly used in trenchless applications.

The following information is offered as an overview. For more detailed information readers should consult the companies and associations involved in the manufacture and supply of pipe directly – for an overview of some of these companies, see our survey over the page.

Steel Pipe

Trenchless applications: Directional drilling, jack-and-bore, horizontal driving (pipe ramming).

Best suited for: Gas transmission, water transmission, water well drilling, pile driving and caisson sleeves.

Limitations: Chemical or corrosive service without protective coatings.

How it is joined: Steel pipe is joined by welding, threading-and-coupling or compression fittings.

Common Diameters: From 3 OD to 1,500 mm OD. Any size and wall thickness that is feasible to transport is available through special order.

Design life: Varies depending on the size, grade and coating application.

Steel pipe has the highest strength-to-weight ratio in relation to cost in the pipe industry. By ordering variations to the content of the raw material, steel pipe can be used in the most extreme of conditions. Steel pipe can also be bent and coiled and is capable of carrying extremely high pressures and volume.

Steel pipe has increased its strength by reducing carbon and increasing yields and tensile strengths. Some sizes can be produced to 100 ksi yield strength. Large diameter pipe can also be regularly produced and shipped in 80 ft lengths, ad with special equipment, in lengths up to 100 ft.

High-density polyethylene (HDPL)

Trenchless applications: HDD, pipe bursting, microtunnelling, sliplining.

Best suited for: Municipal and rural potable water and sewer, forced main sewer, reclaimed water, natural gas, conduit, telecommunications, pipe rehabilitation applications.

Limitations: Continuous temperatures that exceed 60˚C, high concentration of pollutants such as chlorine, petroleum products, organic solvents or their vapours.

How it is joined: Pipe can be either fused (butt fusion or electrofusion) or mechanically joined.

Common Diameters: 15 to 160 mm.

Design life: Up to 100 years, depending on design requirements and water quality.

HDPE pipe can be easily joined to existing infrastructure. HDPE-fused joints are self-restraining and eliminate the need for costly thrust blocks, except at transition to other pipe materials. HDPE has a smooth surface that maintains flow capacity over time. HDPE has performed well during recent earthquakes and tsunamis and has performed well in corrosive environments and does not require protective coatings, cathodic protection, liners or wrapping.

Fibreglass reinforced pipe

Trenchless applications: Microtunnelling, jacking, sliplining, tunnel lining and casings.

Best suited for: Corrosive environments and sanitary sewers. Also available for potable water applications and storm sewers.

Limitations: Gas transmission and other hydrocarbon transmission lines.

How it is joined: Push-together, gasket-sealed joints.

Common Diameters: 450 to 3,000 mm. Larger diameters are possible.

Design life: In excess of 50 years.

Connections to other materials are commonplace. Special fibreglass connections to other materials may be manufactured. Many industry standard connectors, joint seals or laterals are commonly used with FRP.

Fibreglass pipes can be used in a wide range of service conditions. Extreme cold does not affect the product. Fiberglass pipes can be made for operating temperatures up to 70 to 80˚C. The pipe is designed for soil burden, external water pressure and live loading conditions.

The pipe is extremely repairable and easy to modify in the field should conditions warrant. Hydraulic analysis shows superb flow characteristics, ‘n’ value of 0.009 and ‘C’ value of 155. The pipe is extremely abrasion-resistant. Pipe subjected to hydrogen sulphide gases.

Vitrified clay pipe (VCP)

Trenchless applications: Microtunnelling, pipe bursting, pilot tube tunnelling, tunnelling without a casement.

Best suited for: Gravity sanitary and storm sewers.

Limitations: High pressure applications.

How it is joined: Compression joint with low profile stainless steel collar.

Common Diameters: 100 to 1200 mm.

Design life: Based on projected hydraulic capacity. Service life is greater than 100 years.

New clay pipe may be differentiated from old clay pipe by virtue of the following: factory applied flexible compression joints, no joint leakage, computerised drying and firing schedules increase strength and reduce dimensional variation with vacuum de-airing during extrusion producing a denser body.

Compression couplings and/or epoxy field connections to existing infrastructure can be made quickly and cleanly in the field. VCP should be installed below frost line unless special insulating provisions are made to keep pipe from freezing. Heat is not a problem if temperature change is gradual. Thermal shock should be avoided. Good resistance to traffic load using conventional live load calculations.

The recommended ‘n’ factor is 0.010 to 0.013. Clay pipe is resistant to all of the acids, alkalis and solvents normally found in domestic, commercial and industrial sewers.

Polymer concrete pipe

Trenchless applications: Microtunnelling, pipe jacking.

Best suited for: Sanitary sewer or industrial sewer applications where there is a corrosive environment.

Limitations: Currently not designed or approved for pressure or potable water applications.

How it is joined: The standard joint for tunnelling and jacking installations incorporates a push-on stainless steel collar that is mounted integral to the pipe wall. The steel collar mates against an EPDM or SBR rubber gasket firmly joined to the pipe wall.

Common Diameters: 200 to 2,600 in.

Design life: Projected 100-year plus service life.

Polymer concrete pipe is typically compatible with most existing infrastructure systems. The pipe can be installed into standard manholes and structures or polymer concrete manholes and structures are available.

Freezing and extreme heat typically have no effect on the pipe’s capabilities. If the effluent being carried by the pipe is extremely hot (plus 60˚C), the resin used as the binding agent in the pipe can be changed to match the environment.

Polymer concrete pipe is designed to resist pH values from 1 to 10. It has a compressive strength rating of a minimum of 13,000 psi, making it suited for jacking operations. It is also abrasion resistant and has an ‘n’ value of 0.009.

Polyvinyl chloride (PVC)

Trenchless applications: Segmental sliplining, directional drilling, close-fit pipe lining.

Best suited for: Buried water, buried sanitary sewers and buried storm sewers.

Limitations: Extremely high temperature applications where the temperature of the fluid conveyed is consistently greater than 60˚ C. Extremely high-pressure applications where the pressure in consistently more than 300 psi.

How it is joined: Slipliner pipe has a gasketed joint. Close-fit is butt fused. HDD may be butt fused, or it may use a gasketed joint that is locked together with a spline or stainless steel pins.

Common Diameters: Gasketed PV pipe starts at 40 mm and is available up to 1,500 mm for gravity sewer and up to 1,200 in for pressure pipe.

Design life: A properly designed, installed and operated system will last in excess of 100 years.

Manufacturing improvements have increased the size range available for PVC pipe. Technological advancements have made possible the option of butt fusing in the field, which has opened a number of trenchless applications. Innovations have resulted in alternative joint designs more suitable for sliplining, as well as directional drilling and pipe bursting.

PVC is stiff enough that you do not require special connections. PVC is common in water and sanitary sewer applications and connecting to it is considered routine for most utilities.

PVC has an ‘n’ value of 0.009 and a ‘C’ value of 150. PVC is immune to galvanic corrosion because it is a non-conductor and it is immune to electrochemical reactions caused by acids, bases and salts.

Ductile iron pipe

Trenchless applications: HDD, pipe bursting, jack and bore, microtunnelling.

Best suited for: Water and sanitary sewage.

Limitations: Natural gas.

How it is joined: A variety of different rubber-gasketed joints, Mechanical joints, flanged joints, grooved or shouldered joints, ball-and socket joints and a variety of proprietary restrained joints are also available.

Common Diameters: 75 to 1,600 mm.

Design life: When properly installed, 100-plus years.

A large selection of fittings and appurtenances are available for quick and easy connection to ductile iron pipe. Transition couplings, transition gaskets and adaptors are available for connections to other piping materials with different outside diameters.

The strength of ductile iron is its primary feature. It has the capacity to sustain internal, external, columnar and tensile loadings. Because ductile iron pipe has a moderate and dependable coefficient of thermal expansion, few problems are created by changes in service temperature.

The Hazen-Williams ‘C factor’ for cement-mortar-lined ductile iron pipe averages 144 for new pipe and 140 for old pipe (up to 75 years old). The ‘n’ value is generally accepted as 0.011 for cement mortar lining and 0.01 for special lining supplied for ductile iron pipe subjected to hydrogen sulphide gases.

Concrete pipe

Trenchless applications: Pipe jacking, microtunnelling.

Best suited for: Storm drains, culverts and sanitary sewers.

Limitations: Not suited for high-pressure applications. When installed in aggressive environments, protection of the concrete with some type of barrier is needed to prevent deterioration.

How it is joined: Commonly joined using a confined O-ring gasket or profile gasketed joints.

Common diameters: 300 to 3600 mm. Larger diameters can be manufactured using special designs.

Design life: Can be expected to last at least 100 years in a normal, non-aggressive installation.

Concrete pipe is compatible with all types of infrastructure. Concrete pipe is not affected by freeze-thaw, heat or live loads, as long as the pipe is designed for the expected loading. It is desirable to have some cover over the pipe if extreme construction loadings are anticipated.

The Manning roughness coefficient, n, for concrete pipe varies between 0.009 to 0.010. Design values for n are recommended between 0.011 and 0.013 to account for manholes, bends, slime buildup and accumulation of debris.

Higher strength concrete has resulted from higher strength cements, more precise mix designs, admixtures and control of the amount of water used in the mixing process. Automation has resulted in more consistent quality.

Pipe and Conduit Survey 2007

AGRU Australia Pty Ltd Supplies: HDPE, PVDF, ECTFE Minimum diameter: 10 mm Maximum diameter: 1,400 mm

Amiantit Meyer Polycrete Ltd Supplies: PRC Minimum diameter: 200 mm Maximum diameter: 2,600 mm Applications: Microtunnelling, Pipe Jacking, Open Cut

Utilities: Wastewater and Gas Asmuss Plastic Systems Ltd Supplies: PVC, ABS, PVDF Minimum diameter: 125 mm Maximum diameter: 300 mm Utilities: Water, Gas

David Moss Corporation Supplies: HDPE, PVC, Rubber and Ventilation Lengths available: Polyethylene: 20 mm, 25 mm, 32 mm, 38 mm, 50 mm PVC: 50 - 375 mm Ventilation: 305 – 1,400 mm Utilities: Electricity, Communications Standards/certificates: AS/NZS 4058:2007 precast concrete pipes (pressure and non-pressure)

Derwent Pipelines Pty Supplies: Ductile iron, PVC, Steel Utilities: Water, Wastewater, Irrigation DIXON Industries Pty Supplies: Teflon coating, Fusionmaster Maximum diameter: 1,200 mm Utilities: Water, Gas, Mining

The EXCEL Group Supplies: Vitrified Clay Lengths available: 150 mm, 225 mm, 300 mm, 900 mm, 1,000 mm, 1,200 mm Minimum diameter: 400 mm Maximum diameter: 1,200 mm Applications: Microtunnelling, Pipe Jacking Utilities: Water

Hobas Engineering GmbH Supplies: Fibreglass reinforced Minimum diameter: 200 mm Maximum diameter: 2,700 mm Applications: Microtunnelling, Pipe Jacking, Slip Lining Utilities: Hydro Power, Wastewater, Electricity

Humes Supplies: Concrete, Vitrified Clay, Steel, Corrosion Protection Linings Lengths available: 2,400 mm Minimum diameter: 275 mm Maximum diameter: 5,100 mm Applications: Microtunnelling, Pipe Jacking Utilities: Water, Wastewater, Sleeve Standards/certifications: AS 4058 AS 9001 - 2000

Hynds Pipe Systems Supplies: Concrete Minimum diameter: 610 mm Maximum diameter: 2,032 mm Applications: Pipe Jacking, Joint Pipes Utilities: Wastewater, Stormwater

Iplex Pipelines Australia PTY Limited Supplies: Fibreglass reinforced, Polymer Concrete, PVC, HDPE Lengths available: 3 m, 4 m, 6 m, 12 m, 18 m, Coils 100 m. Minimum diameter: 32 mm Maximum diameter: 3,000 mm Applications: Microtunnelling, Pipe Jacking, Pipe Bursting, Slip Lining, HDD Utilities: Water, Communications, Wastewater, Gas, Electricity Standards/certifications: All Iplex manufacturing plants have ISO 9002 quality assurance programs. All pipes are manufactured to relevant Australian Standards.

Kenkar Plastics Pty Ltd Supplies: HDPE Utilities: Water, Wastewater, Gas, Electricity, Stormwater Leap Australasia Supplies: Fibreglass reinforced, Polymer concrete, Vitrified Clay Lengths available: 1 to 2 m Minimum diameter: 100 mm Maximum diameter: 2,000 mm Applications: Microtunnelling, Pipe Jacking, Slip Lining Utilities: Wastewater

Marley NZ Ltd Supplies: Concrete, PVC, Vitrified Clay Minimum diameter: 75 mm Maximum diameter: 200 mm Utilities: Water, Wastewater Maskell Productions Ltd Supplies: Fibreglass reinforced Lengths available: Anything up to 12 m Minimum diameter: 50 mm Maximum diameter: 3,000 mm Applications: Slip Lining Utilities: Water, Wastewater Standards/certifications: ISO9001

Mico Pipelines Supplies: Ductile iron, HDPE, PVC, ACO, Vitrified Clay Utilities: Water, Wastewater

Pipe King Supplies: PVC, SC DMV Minimum diameter: 40 mm Maximum diameter: 225 mm Utilities: Stormwater

Plasson Australia Types of fittings do you supply: HDPE Lengths available: All sizes Minimum diameter: 16 mm Maximum diameter: 500 mm Applications: Microtunnelling, Boring, Pipe Bursting, Slip Lining Utilities: Water, Wastewater, Communications, Gas, Electricity Standards/certifications: AS4129

Rocla Pipeline Products Supplies: Concrete Minimum diameter: 225 mm Maximum diameter: 3 m Lengths available: 2.44 m is standard Applications: Pipe Jacking Utilities: Water, Wastewater

Tyco Water Supplies: PVC, Ductile iron, Steel, ABS Lengths available: 2 – 13.5 m Minimum diameter: 114 mm Maximum diameter: 2,400 mm Applications: Boring, Microtunnelling, Pipe Jacking, Slip Lining Utilities: Water, Wastewater Standards/certifications: AS1579/ AS4801/ AS1477/ AS3518/ AS2280

Van Leeuwen Pipe and Tube Supplies: Steel, Carbon and Stainless Lengths available: Made to measure Utilities: Water, Gas, Construction and Infrastructure Standards/certifications: ISO 9001 Certificate

Vinidex Pty Ltd Supplies: HDPE, PVC Lengths available: PVC: 150 mm-375 mm, Polyethylene: 16 mm to 1,000 mm Minimum diameter: 16 mm Maximum diameter: 1,000 mm Applications: Microtunnelling, Pipe Bursting, Slip Lining, Directional Drilling Utilities: Water, Communications, Wastewater, Gas, Electricity, Industrial and Mining

WorldPoly Pty Ltd Supplies: PVC, PVDF, PE, PP Minimum diameter: 1,200 mm Maximum diameter: 1,600 mm