Polyethylene encasements (Polywrap) have long been proven as a cost-effective way to prevent corrosion and extend the life of ductile iron pipe systems. Polywrap works by creating a barrier between the corrosive soil and the pipe and effectively slowing down the corrosion rate. This is achieved by creating an environment where the initial oxygen that is buried with the pipe is depleted, creating minor surface oxidation. The Polywrap prevents any further oxygen from entering the space between the wrap and the pipe, thereby preventing any further corrosion of the pipe. Polywrap also has a high dielectric strength that combats stray currents in the soil that also can corrode ductile iron.
Enhanced polyethylene is made from 8-mil thickness, linear low-density polyethylene and manufactured according to ANSI/AWWA C105/A21.5. This standard requires that the Polywrap be manufactured from 100% virgin polyethylene resins with properties that meet certain tensile strength, elongation, dielectric strength, impact resistance, and tear resistance parameters. In addition to these properties, the enhanced polyethylene is manufactured with additives that help combat initial corrosion and anaerobic bacteria.
AA Thread’s VB3 Enhanced Polyethylene is a three-layer, co-extruded film. The film not only creates a barrier between the corrosive soil and the pipe but is infused with an antimicrobial biocide as well as a volatile corrosion inhibitor (VCI). It exceeds all of the ANSI, AWWA, and ASTM standards required of polyethylene encasements. The antimicrobial additive fights anaerobic corrosion caused by sulfate-reducing bacteria. The biocide in the wrap will prevent the growth of bacteria on the pipe system. The VCI mixes with any corrosive liquids that might seep between the wrap and the pipe and neutralizes them.
AA Thread Seal Tape has been in business since 1979 supplying wholesalers and distributors in the water/wastewater and plumbing industries with quality products, including polyethylene encasements for ductile iron pipe, pipe wrapping tapes, detectable/non-detectable tapes, PTFE thread seal tapes, sealants, and more. Learn more at aathread.com