Three Layer Polyethylene/ Polypropylene coating Systems (3LPE/PP), a multi layer coating composed of three functional components: a high performance fusion bonded epoxy (FBE) followed by a copolymer adhesive and an outer layer of polyethylene/polypropylene which provides tough and durable protection. 3LPE/PP Systems provide excellent pipeline protection for small and large diameter pipelines with moderately high operating temperatures.
The 3-LPE/PP Coated Pipe are as Follows:
Pipes are preheated, external blasting is carried out for cleaning and roughness then inspected. In case of high salt contamination the pipes are treated with phosphoric acid and washed with high pressure DM water to neutralize the chloride contents. The pipes are loaded on coating conveyor and heated between 180-2300C or as per powder manufacturer’s recommendation.
Three Layer PE/PP Coting
Layer 1: This is the corrosion protective layer. This layer is of fusion bonded epoxy
which offers very good corrosion protection. The fusion bonded epoxy has a very good
bonding with the blasted steel surface.
Layer 2: This layer is the copolymer adhesive. The copolymer adhesive is a malefic
anhydride grafted polyethylene compound. This material has good chemical bonding to
the fusion bonded epoxy and the top layer polyethylene.
Layer 3: This layer is for physical protection and consists of
polyethylene/Polypropylene. Since the copolymer adhesive and polyethylene are
similar, they bond well with each other.
After coating, pipes are passed through quenching zone to bring down the temperature below 80°C for smooth handling and cut back operation as per client requirement. Pipes are tested with Holiday detector with 25 KV voltage to detect pin holes and other various testing peel test, thickness check, impact test and lab tests etc for coated pipes and raw materials.