Subline - Tight-Fit Polyethylene Lining
PIM Corporation's Subline system uses standard polyethylene (PE) pipe to create a close-fit liner within an existing pipe with very little excavation. Up to 3,000 feet of new PE pipe can be inserted into an existing pipeline between entry and exit pits. Moments before installation, a PE pipe is pushed through a special die which folds the pipe into a 'C' shape which is temporarily held by plastic straps. The folded pipe can easily be pulled through an existing pipeline. Once the PE pipe extends completely through the host pipe, its ends are sealed and the pipe is filled with water and pressurized. The pressure causes the plastic straps to break and the PE pipe to unfold and return to its original shape. As a result, the PE pipe fits tightly inside the host pipe, sealing leaks, preventing corrosion, and reducing friction.
- Cold Process: No heating equipment required. The entire process is carried out at ambient temperatures.
- Minimal Elongation: Low winching forces minimize residual stresses after installation.
- Start-Stop Capability: The process may be stopped at any point in the installation process and then safely started again.
- Available for 3' through 60' pipe
- Wall thicknesses from 1/4' to 1' (SDR > 26)
- Installation lengths up to 3,000' in single pulls are possible
- Can negotiate bends up to 45°
- Stops leaks and internal corrosion
- Tight fit, thin wall, and smooth bore maximizes flow capacity
- Uses standard PE pipe with known physical properties and design life
- Installation does not harm adjacent utilities
- Cleaning: The host pipe is cleaned to remove internal corrosion and other deposits.
- Inspection: The pipeline is inspected by CCTV. Any problems, such as protruding taps are dealt with at this time.
- Pipe Preparation: The jointless polyethylene (PE) pipe 'string' is created by the butt-fusion welding of shorter, individual lengths which can be supplied as coils or sticks.
PE Processing: The PE pipe is passed through a Subline machine which forms it into a 'C' shape. Straps are added to help the pipe retain its folded shape while it is pulled through the host pipeline.
Reversion: The PE pipe is filled with water and pressurized. This causes the PE pipe to break its retaining straps and to return to its original, circular shape, forming a close-fit, thin-wall liner.
Reconnection: The lined sections of mains are reconnected to the system and to service lines via proprietary couplings and fittings designed specifically for use with lined mains.