State of Technology Report for Force Main Rehabilitation, Final ...

US. Primus Line is a seamless, woven hose made of aramid (Kevlar ® ) fiber in single or double layer
designs (depending on pressure) embedded in a high performance plastic matrix. Kevlar has eight times
the tensile strength of steel. The folded pipe is pulled into an existing pipe from a reel. This is not a CIPP
product so no curing is required. Pressure is used to inflate the liner which then becomes self-supporting.
For water or sewer applications, the inner liner is coated with polyethylene. There is also an outer coating
of wear resistant PE. Primus Line is also used for oil and gas applications in which the liner is coated
with TPU. The main benefit of Primus Line is its ability to handle high pressure. With a single layer of
woven fabric, the pressure rating for 6 inch (150 mm) diameter is nearly 500 psi (34.5 bar) and for 20
inch (500 mm) diameter it is rated at 218 psi (15 bar). The rating can be higher with a double fabric layer.
Primus rates its product based on a factor of safety of 2.5 against the burst strength, but also claims that
long-term creep pressure tests have been conducted in accordance to DIN 16887 and ISO 9080. The
product has a safety coefficient of 2.0 applied to the extrapolated 50 year strength. The only available
product standards for Primus Line are German, namely KTW and W270 for drinking water in Europe,
and DVGW Testing Basis VP 643 (June 2004). For insertion, the existing pipe must be CCTV inspected
and any sharp protrusions that might damage the liner are ground smooth. The Primus Line is pulled
from a reel (up to 6,000 feet [1,829 meters]) into the pipeline. A special pulling head is used to help
protect the liner from any remaining sharp objects. The rate of installations can be up to 1,200 feet (366
meters) per hour. The maximum pulling force is 100 kilo Newtons (kN) and a load cell with recorder is
used to monitor that this force is not exceeded. The main drawback of the Primus Line is that a very
special, proprietary connector is needed to join the line to a welded or flanged connection on the original
pipe. This special connector requires a resin to be injected and cured before the line can be pressure
tested and put back into service. One potential application for the Primus Line might be as a by-pass
pipe. It is very light weight (1.6 to 9.1 kg/m), quick to unreel, and set up.
3.4.5.3 Glass-Reinforced Thermoplastic Liner
Structural Woven Hose Lining
Aqualiner
Aqualiner is an emerging technology that appears to have great promise. It is still undergoing
development trials in Europe and has not yet been commercially released. The developer, Aqualiner, is a
consortium of three UK water companies, a Danish contractor, and a plastics consultant. All of the field
trials have been with Wessex Water in the UK. The Aqualiner installation process is shown in Figure 3­
20. Aqualiner involves winching a glass fiber reinforced polypropylene sock into a deteriorated pipe, and
once the sock is in place, pushing a heated pig with a silicone rubber inflation tube through the sock,
melting the thermoplastic sock against the pipe wall. The inversion bag presses the molten thermoplastic
composite sock against the pipe wall where it cools to form a solid glass reinforced thermoplastic liner.
Pressure in the inflation bag is kept at 45 psi (3 bar) until the liner cools, at which point the bag is deflated
and removed. There is no mixing of chemicals and no environmental releases. The liner is fully
structural (Class IV), capable of handling the internal pressure, and external loads. An application for UK
approval for potable water is in process (DWI Regulation 31) as well as for certification for NSF 61.
Aqualiner will also be able to meet the strain corrosion requirements of Table 6 in EN 13566-4:2002,
which is similar to those in ASTM D3262. Aqualiner will be available in diameters of 6 to 12 inches
(150 to 300 mm) (eventually 18 inches [450 mm]) and will have a 150 psi (10 bar) pressure rating.
Renewal length of up to 500 feet (152 meters) for 12 inch (300 mm) pipe can be undertaken. There are
no product standards yet for this new class of liner product. The closest applicable standard might be EN
ISO 15874 Polypropylene for Hot and Cold Water Installations. Likewise, there are no design standards,
with EN 13566-4:2002, Plastic Piping Systems for Renovation of Underground Sewerage Networks
(CIPP) the most applicable.
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