Client:
Major global oil company
Year of Construction:
2019
Type of Construction Measure:
Rehabilitation of a DN 400/16” fire main
Our Services:
• Pipe construction engineering
• Material supply and logistics
• Installation of the Primus Line® system
• Site management
Situation:
A major global oil company was confronted with a leaking DN 400/16” PVC pipe located inside a refinery transporting water for the fire protection system. Analysing the site and pipe structure for the client, Primus Line recommended to install four sections with a total length of 160 m to be renovated. The clearly laid out project plan has been tailored exactly to the conditions of the site and the clients’ needs and requirements.
Technical Details:
Material of Host Pipe: PVC
Transported Fluid: Firefighting water
Diameter of Host Pipe: DN 400/16”
Operating Pressure: 10 bar
Primus Line® System: DN 400/16” PN 32;
connectors DN 400/16” with flanges ANSI class 150 Total Length: 160 m Number of Sections: 4 sections with multiple bends up to 90° Installation Time: 5 working days
Rehabilitation System:
The Primus Line® system is referenced in EN ISO 11295:2017 – classification on design and applications of plastics piping systems used for renovation and replacement. It also complies with the technical standard DVGW VP 643 – flexible textile-reinforced plastic inliner for pipe-relining of gas high pressure pipes. The sys-tem consists of a Kevlar®-reinforced liner and specifically developed end fittings. The liner accommodates the operating pressure of the pipe, due to the reinforcement layer and does not bond to the host pipe. An annulus space remains. Due to the material flexibility, the liner can traverse angles of up to 90° and can be installed in lengths of more than 1,000 m in one pull and has an installation speed of up to 600 m per hour.
During factory acceptance testing, a burst pressure test was conducted on the produced liner DN 400 high pressure as well as the connector. The test results showed a burst pressure of the liner of 92 bar. Long term tests according to DVGW VP 643 and ISO 9080 determined a fabric factor of 2.0 to achieve a life span of 50 years. In addition, a safety factor of 1.25 is incorporated. Hence, the pipeline can be safely operated with a MOP of 10 bar. The inner coating of the liner is made from polyethylene (PE).
Project Description:
The construction site with 5 installation pits was set up by the client. After finishing the pits, the fire main to be renovated was isolated from the network and shut down. Spool pieces were cut in the pits and all the fittings and T-pieces were removed.
The pre-installation CCTV inspection revealed an existing film and deposits on the inner surface of the PVC pipe. The necessary cleaning was performed by pulling rubber disks/plungers through the host pipe. After a subsequent CCTV inspection, the pipe showed the “free inner diameter” and was ready for the insertion of the Primus Liner. The Primus Line hose which was pre-folded at the manufacturer’s facility was delivered to the site coiled onto special installation drums. Based on the U-shaped hose, the pulling forces were reduced to a minimum and therefore the 90° bends along the installation sections were not challenging.
The maximum tolerable pulling force for the Primus Line hose DN 400/16” PN 32 is 100 kN. During the four installations, a pulling force of maximally 50 kN was measured.
After pulling the Primus Liner in, it was inflated to its round shape and the connectors were assembled. Each rehabilitated section was leak-tested by performing a pressure test. With the installation of the spool pieces in the pits, the rehabilitation of the fire main was completed successfully and handed over to the client.
