- Polyvinyl Chloride
Polyvinyl Chloride (PVC) pipe is used widely in the construction of distribution systems. The ease of construction, lower cost, and resistance to corrosion are the main reasons for its wide use. In addition, PVC has a very favourable C factor that lessens its resistance to flow and therefore has better hydraulic performance characteristics than other types of pipe materials.
- Asbestos Cement
Asbestos Cement (AC) pipe is made from asbestos fibre, silica sand, and cement. The strength of the pipe is derived mostly from the asbestos fibre. AC is not prone to corrosive attack, burning or deterioration because of the materials used in its construction. The pipe is lighter than a ductile iron pipe of equal size and class, and is relatively easy to handle and join. Because of its smooth uniform bore, AC pipe has a carrying capacity slightly less than PVC pipe. AC pipe is rigid and cannot be bent or twisted.
Since the pipe is manufactured to cast iron Outside Diameter (OD) sizes, the pipe is compatible with piping systems manufactured to cast iron OD sizes such as PVC Class pipe and ductile iron pipe. AC pipe is manufactured in accordance to AWWA C400 and is generally available in three pressure classes for sizes 10 to 90 cm (4 to 36 inch). Pipe classifications and hydrostatic strengths are listed in the table above.
- Ductile Iron
Ductile iron is manufactured in sizes ranging from 10 to 60 cm (4 to 24 inches). Ductile iron pipe will take some bending and twisting without breakage. To protect internal pipe walls from corrosion, cement mortar or other approved linings are used. Bituminous or polyethylene coatings are used to protect the outside of the pipe,
The pipe is manufactured to cast iron OD sizes as are PVC and AC pipe. It is easily adaptable for use in distribution systems having cast iron OD sizes. Ductile iron pipe is manufactured in accordance to AWWA C151 and CSA B131 (ANSIA 21.51). For all pipe sizes, 7.5 to 45 cm (3 to 18 inch), the pressure rating is 2400 kPa (350 psi) with an accompanying maximum hydrostatic test pressure equalling 3450 kPa (500 psi). Wall thicknesses are different for each pipe size.
- Steel Pipe
Steel pipe is used mostly for transmission mains where internal pressures are higher than would normally be experienced in distribution systems. Steel pipe has a very high tensile strength and can withstand enormous internal pressures before failing. Steel pipe is lighter than ductile and concrete pipe and has a competitive cost when installed in high pressure applications.Because of iys metal composition, steel pipe is subject to attack by corrosive water and/or soils. To protect the pipe, internal coat tar epoxy linings and cement linings are used. For exterior pipe protection, polyethylene linings are used. Cathodic protection is another form of corrosion prevention.
- Concrete Pressure Pipe
Concrete pressure pipe combines the compressive strength of an inner steel cylinder, reinforced with steel wire. Concrete pressure pipe is manufactured in accordance to AWWA C300, C301, C302 and C303. The pipe is available in pressure ranges from 300 to 2800 kPa (45 to 400 psi) depending on the desired size and applicable AWWA specification.
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