April 2018, Vol.245, No.4
TechNotes
System Repairs Pipe Through Direct Bonding
The patented PolyBrute system is a structural reinforcing system developed by Milliken Infrastructure Solutions (MIS) for the reinforcement or repair of damaged polyethylene and polypropylene pipe.
This system is the first method available in the market that can bond directly to polyethylene and polypropylene materials, while reducing repair time by 50% or more when compared to traditional repair methods, the company said.
The PolyBrute system can be applied in the field without cutting and replacing, and uses just the application of low heat to bond. Additionally, this system can help provide a safer repair alternative, without causing residual damage to the existing pipe. Key applications include olefin pipe in environments that are subject to physical and chemical damage leading to defects such as gouges, cracks, degraded joint connections, squeeze tool damage and poly-coated repair.
This repair system has been extensively tested for MDPE by GTI to develop information on the permanency and life expectancy of the repairs. GTI testing confirmed that sample pipes repaired using the PolyBrute system would last at least 20 years in the field under normal operating conditions. Testing is ongoing and researchers are continuing to monitor the status of specimens under long-term hydrostatic pressure testing.
When installing the system, a technician must:
- Surface prep: Prepare the outer surface and defect for next steps to ensure good adhesion between the pipe and additional layers.
- Repair defect: When necessary, fill the defect using filler material provided by MIS. When filler has cured for about five minutes, sand the area to match pipe circumference.
- Attach machine: After repairing the defect, attach the machine when applicable to the pipe by clamping both ends and tightening the screws to ensure it is well attached. The machine is equipped with elastomer gaskets to ensure clamping that won’t damage the surface of the pipe.
- Apply adhesive layer: The adhesive should overlay the defect and at least two inches beyond either side of the defect along the entire length and circumferential directions on the pipe. Apply shrink film over the adhesive film before and during the step of applying heat to film.
- Fuse adhesive film: This step can be done by hand or machine.
- Apply reinforcing material: Wrap the uncured material in a hoop fashion around the circumference of the pipe. For longer repair areas, the material can be wrapped in a spiral fashion with a 50% overlap around the circumference of the pipe.
- Apply constrictor wrap: Apply the film and perforate to allow reaction gases to escape during cure. Remove constrictor wrap after the material has cured. P&GJ
Comments