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