pe sleeve  

https://www.slrfoundry.com/pipes-list/polyethylene-sleeving-for-di-pipe.html

Polyethylene Sleeving for DI Pipe

Polyethylene sleeving, often referred to as PE film or polyethylene film, is commonly used as a corrosion protection solution for ductile iron pipes in various industries, including water distribution and wastewater management.

Polyethylene Sleeving (PE film) for Ductile Iron Pipe

PE sleeving is the Polyethylene or a mixture of polyethylene and/or ethylene and olefin copolymers sleeve (film) with a thickness of 0.2mm that is wrapped on the external walls of the pipe on the construction site. It can prevent direct contact between cast iron pipes and the soil. Meanwhile, it also prevents underground moisture from corroding the pipelines. It is used to supplement the basic pipe coating (metallic Znic + HCPE finishing layer) in certain cases of highly corrosive soils or in the presence of stray currents.

The anti-corrosion mechanisms for PE sleeve (film) wrapped outside zinc coating are as follows: First of all, PE sleeve can separate the pipelines from corrosive soil and inhibit the generation of electrochemical cells. At the same time, it can also isolate stray currents. The PE sleeve is a kind of anti-corrosion method whose performance is achieved through the changing of a corrosive environment: it can change the corrosive environment from non-homogeneous soil with strong aggressivity into one that is homogeneous with weak aggressivity.